Preparing for your Cisco Certified Network Associate (CCNA) can be a nerve-racking experience. The CCNA requires that you take an exam to prove your competence in routing, switching and connectivity. This exam is valid for three years, at which time you will need to re-take the CCNA to continue your certification.A CCNA is a beginning-level certification, and gives you a solid foundation in Cisco networking. The demand for CCNAs has been rising over the last several years, so if you are interesting in network engineering or you want to give you career a boost, this certification is a must. There are many training programs aimed at preparing you for this exam. If you are serious about taking the CCNA, you should take advantage of these programs to ensure your successs in passing the CCNA. If a classroom setting is too expensive, time-consuming or just not practical to help you prepare, there are many training programs that you can purchase and use at home. With this type of training, you can learn at your own pace. Because this kind of preparation is so popular, there are a variety of programs available to meet your preparation needs. These programs can include training videos hosted by real-world professionals walking you through specific tasks and giving you hands-on knowledge. Accompanying materials may include workbooks to help you master your skills, and practice questions that can help you prepare for the questions on your CCNA exam. Adequate preparation is a must if you are serious about getting your CCNA certification. With the large variety of programs available, you should look around and find the one that suits your learning needs the best. Some good things to look for in a CCNA training program are:-Tips and training from real-world professionals If you want to learn through videos, find a program that is instructed by a well-qualified professional. The highest certification that you can obtain is a Cisco Certified Internetwork Expert (CCIE). A CCIE with real-world Cisco network experience would be the best instructor. -Accompanying Materials Workbooks are a great way to practice and enhance your skills and retain knowledge.. Other great preparation materials inlcude practice questions. Combined with video instruction and workbooks, knowing how to apply your knowledge and skills in an exam situtation may be the final resource you need to be fully prepared for your CCNA.Taking and passing a CCNA is an important step in your career, so you should be prepared. Find a training program that will prepare you and give you the skills, knowledge and confidence you need to pass the CCNA.
Wednesday, January 9, 2008
Cisco Networking Academy @ Edison Community College
Edison Community College offers classes to achieve technical certifications using the Cisco Networking Academy Program. All classes also apply toward several Associate degrees.
Potential certifications represented by our Cisco Academy classes include:
Cisco Certified Network Associate (CCNA)
Cisco Certified Network Professional (CCNP)
Cisco Firewall Specialist
Cisco Advanced Wireless LAN Field Specialist (AWLANFE)
CompTIA A+
CompTIA Server+
CompTIA Security+
Panduit Certified Technician (PCT)
CLASSES
CIT 211S OPERATING SYSTEMS CONCEPTS (HP IT ESSENTIALS II)In depth study of operating systems concepts, organization and functions that are incorporated in any modern operating system including commands used in a working systems environment. Topics include single and multi-user systems, single and multi-tasking systems and graphical user interfaces. Operating systems for microcomputers, work stations, minicomputers and mainframe computers are explored.
CIT 215S MICROCOMPUTER HARDWARE (HP IT ESSENTIALS I)In-depth, hands-on exploration of microcomputer hardware, components and peripherals. Emphasis on the importance of the microcomputer specialist's ability to recognize, install, change and modify computer systems and components. Configuration and connection of peripheral equipment is explored, as is the installation of network hardware and cabling.
CSC 115S FUNDAMENTALS OF VOICE AND DATA CABLING (PNIE)Provides and interview of cabling and networking industry standards as well as emerging cabling technologies. Students will document, design and install network cabling, describe laboratory safety and on-the-job safety, and work effectively in group environments. Students will become familiar with cabling issues related to data and voice connections, media and transmissions practices, and cabling customer support. The content of this course helps prepare students for the Panduit Certified Technician certification exam.
CSC 116S FUNDAMENTALS OF NETWORK SECURITY (FNS)Provides students with the knowledge and skills necessary to design and implement fundamental network security solutions to reduce the risk of revenue loss and vulnerability of network resources. Fundamentals of Network Security helps prepare students to take the SECUR (Securing Cisco IOS Networks) and CSPFA (Cisco Secure PIX Firewall Advanced) exams in preparation for the Cisco Firewall Specialist. These exams also count toward security-professional-level CCSP certification. Successful completion of the course also helps prepare students for the CompTIA Security+ exam.
CSC 117S FUNDAMENTALS OF WIRELESS LANS (FWL)Provides students with the knowledge and skills necessary to understand radio technologies associated with WLAN 802.11 standards, understand WLAN and bridge topologies and applications, configure WLAN products including access points, bridges, client devices and accessories, explain software and management features, configure various security methods for Wireless LAN environments, understand basic antenna theory, and understand how to perform a site survey covering WLAN topology and design. Fundamentals of Wireless LANs helps students to achieve the Cisco Wireless LAN Support Specialist designation (WLANFE).
CSC 110S NETWORKS AND LAYERS (CCNA 1)Provides students with an introduction to the computer and data networking field. Focuses on network terminology and protocols, local-area networks (LANs), wide-area networks (WANs), Open System Interconnection (OSI) models, cabling, cabling tools, routers, router configuration, Ethernet, Internet Protocol (IP) addressing, and networking standards. First of four courses helping students prepare for the Cisco Certified Network Associate (CCNA) certification exam. Prerequisite: grade of “C” or better in CIT 215S or A+ certification or department approval. Lab fee.
CSC 111S ROUTER USE (CCNA 2)Provides students with the knowledge and skills necessary for initial router configuration, router software management, routing protocol configuration, TCP/IP, and access control lists (ACLs). Second of four courses helping students prepare for the Cisco Certified Network Associate (CCNA) certification exam. Prerequisite: grade of “C” or better in CSC 110S. Lab fee.
CSC 130S VIRTUAL LANS (CCNA 3)Provides students with the knowledge and skills necessary for Variable Length Subnet Masks (VLSM), intermediate routing protocols such as RIP v2, single-area OSPF, and EIGRP, performing command-line interface configuration of switches, Ethernet switching, virtual LANs (VLANs), spanning tree protocol (STP), and the VLAN trunking protocol (VTP). Third of four courses helping students prepare for the Cisco Certified Network Associate (CCNA) certification exam. Prerequisite: grade of “C” or better in CSC 111S. Lab fee.
CSC 131S WIDE AREA NETWORKING (CCNA 4)Provides students with a study of wide area networks (WANs) including advanced IP addressing techniques, network address translation (NAT), port address translation (PAT), dynamic host configuration protocol (DHCP), WAN technology and terminology, PPP, ISDN, DDR, frame relay, and network management. Fourth of four courses helping students prepare for the Cisco Certified Network Associate (CCNA) certification exam. Prerequisite: grade of “C” or better in CSC 130S. Lab fee.
CSC 150S ADVANCED ROUTING (CCNP 1)Introduction to advanced routing protocols required on scalable networks. Topics include OSPF, EIGRP, and BGP operations and configuration. Building Scalable Networks addresses those tasks that network managers and administrators need to perform when managing access and controlling overhead traffic in growing, routed, networks once basic connectivity has been established. BSN discusses router capabilities used to control traffic over LANs and WANs, as well as connecting corporate networks to an Internet Service Provider (ISP). Prepares the student to pursue the Cisco CCNP examination. Prerequisite: CSC 131S or CCNA certification.
CSC 151S REMOTE ACCESS (CCNP 2)The study of how to build a remote access network to interconnect central sites to branch offices and home office/telecommuters and then control access to the central site, as well as maximize bandwidth utilization over the remote links. Prepares the student to pursue the Cisco CCNP examination. Prerequisite: CSC 131S or CCNA certification. Lab Fee.
CSC 170S MULTI-LAYER SWITCHING (CCNP 3)The study of building campus networks using multi-layer switching technologies over high speed Ethernet. The class will include an overview of SPT, bridging, switching and VLAN management. Students will also design, configure and troubleshoot multi-layered switched and routed networks. The class is designed to prepare the student to pursue the Cisco CCNP examination. Prerequisite: CSC 131S or CCNA certification.
CSC 171S NETWORK TROUBLESHOOTING (CCNP 4)The study of how to baseline and troubleshoot a LAN and WAN environment. Students learn to test and identify problems with routers and switches in multiprotocol environments. Topics include Ethernet, Fast Ethernet, and Token Ring LANs, Serial, Frame Relay and ISDN BRI WANs. The class is designed to prepare the student to pursue the Cisco CCNP examination. Prerequisites: CSC 150S, CSC 151S, and CSC 170S.
Potential certifications represented by our Cisco Academy classes include:
Cisco Certified Network Associate (CCNA)
Cisco Certified Network Professional (CCNP)
Cisco Firewall Specialist
Cisco Advanced Wireless LAN Field Specialist (AWLANFE)
CompTIA A+
CompTIA Server+
CompTIA Security+
Panduit Certified Technician (PCT)
CLASSES
CIT 211S OPERATING SYSTEMS CONCEPTS (HP IT ESSENTIALS II)In depth study of operating systems concepts, organization and functions that are incorporated in any modern operating system including commands used in a working systems environment. Topics include single and multi-user systems, single and multi-tasking systems and graphical user interfaces. Operating systems for microcomputers, work stations, minicomputers and mainframe computers are explored.
CIT 215S MICROCOMPUTER HARDWARE (HP IT ESSENTIALS I)In-depth, hands-on exploration of microcomputer hardware, components and peripherals. Emphasis on the importance of the microcomputer specialist's ability to recognize, install, change and modify computer systems and components. Configuration and connection of peripheral equipment is explored, as is the installation of network hardware and cabling.
CSC 115S FUNDAMENTALS OF VOICE AND DATA CABLING (PNIE)Provides and interview of cabling and networking industry standards as well as emerging cabling technologies. Students will document, design and install network cabling, describe laboratory safety and on-the-job safety, and work effectively in group environments. Students will become familiar with cabling issues related to data and voice connections, media and transmissions practices, and cabling customer support. The content of this course helps prepare students for the Panduit Certified Technician certification exam.
CSC 116S FUNDAMENTALS OF NETWORK SECURITY (FNS)Provides students with the knowledge and skills necessary to design and implement fundamental network security solutions to reduce the risk of revenue loss and vulnerability of network resources. Fundamentals of Network Security helps prepare students to take the SECUR (Securing Cisco IOS Networks) and CSPFA (Cisco Secure PIX Firewall Advanced) exams in preparation for the Cisco Firewall Specialist. These exams also count toward security-professional-level CCSP certification. Successful completion of the course also helps prepare students for the CompTIA Security+ exam.
CSC 117S FUNDAMENTALS OF WIRELESS LANS (FWL)Provides students with the knowledge and skills necessary to understand radio technologies associated with WLAN 802.11 standards, understand WLAN and bridge topologies and applications, configure WLAN products including access points, bridges, client devices and accessories, explain software and management features, configure various security methods for Wireless LAN environments, understand basic antenna theory, and understand how to perform a site survey covering WLAN topology and design. Fundamentals of Wireless LANs helps students to achieve the Cisco Wireless LAN Support Specialist designation (WLANFE).
CSC 110S NETWORKS AND LAYERS (CCNA 1)Provides students with an introduction to the computer and data networking field. Focuses on network terminology and protocols, local-area networks (LANs), wide-area networks (WANs), Open System Interconnection (OSI) models, cabling, cabling tools, routers, router configuration, Ethernet, Internet Protocol (IP) addressing, and networking standards. First of four courses helping students prepare for the Cisco Certified Network Associate (CCNA) certification exam. Prerequisite: grade of “C” or better in CIT 215S or A+ certification or department approval. Lab fee.
CSC 111S ROUTER USE (CCNA 2)Provides students with the knowledge and skills necessary for initial router configuration, router software management, routing protocol configuration, TCP/IP, and access control lists (ACLs). Second of four courses helping students prepare for the Cisco Certified Network Associate (CCNA) certification exam. Prerequisite: grade of “C” or better in CSC 110S. Lab fee.
CSC 130S VIRTUAL LANS (CCNA 3)Provides students with the knowledge and skills necessary for Variable Length Subnet Masks (VLSM), intermediate routing protocols such as RIP v2, single-area OSPF, and EIGRP, performing command-line interface configuration of switches, Ethernet switching, virtual LANs (VLANs), spanning tree protocol (STP), and the VLAN trunking protocol (VTP). Third of four courses helping students prepare for the Cisco Certified Network Associate (CCNA) certification exam. Prerequisite: grade of “C” or better in CSC 111S. Lab fee.
CSC 131S WIDE AREA NETWORKING (CCNA 4)Provides students with a study of wide area networks (WANs) including advanced IP addressing techniques, network address translation (NAT), port address translation (PAT), dynamic host configuration protocol (DHCP), WAN technology and terminology, PPP, ISDN, DDR, frame relay, and network management. Fourth of four courses helping students prepare for the Cisco Certified Network Associate (CCNA) certification exam. Prerequisite: grade of “C” or better in CSC 130S. Lab fee.
CSC 150S ADVANCED ROUTING (CCNP 1)Introduction to advanced routing protocols required on scalable networks. Topics include OSPF, EIGRP, and BGP operations and configuration. Building Scalable Networks addresses those tasks that network managers and administrators need to perform when managing access and controlling overhead traffic in growing, routed, networks once basic connectivity has been established. BSN discusses router capabilities used to control traffic over LANs and WANs, as well as connecting corporate networks to an Internet Service Provider (ISP). Prepares the student to pursue the Cisco CCNP examination. Prerequisite: CSC 131S or CCNA certification.
CSC 151S REMOTE ACCESS (CCNP 2)The study of how to build a remote access network to interconnect central sites to branch offices and home office/telecommuters and then control access to the central site, as well as maximize bandwidth utilization over the remote links. Prepares the student to pursue the Cisco CCNP examination. Prerequisite: CSC 131S or CCNA certification. Lab Fee.
CSC 170S MULTI-LAYER SWITCHING (CCNP 3)The study of building campus networks using multi-layer switching technologies over high speed Ethernet. The class will include an overview of SPT, bridging, switching and VLAN management. Students will also design, configure and troubleshoot multi-layered switched and routed networks. The class is designed to prepare the student to pursue the Cisco CCNP examination. Prerequisite: CSC 131S or CCNA certification.
CSC 171S NETWORK TROUBLESHOOTING (CCNP 4)The study of how to baseline and troubleshoot a LAN and WAN environment. Students learn to test and identify problems with routers and switches in multiprotocol environments. Topics include Ethernet, Fast Ethernet, and Token Ring LANs, Serial, Frame Relay and ISDN BRI WANs. The class is designed to prepare the student to pursue the Cisco CCNP examination. Prerequisites: CSC 150S, CSC 151S, and CSC 170S.
CCNA - Cisco Certified Network Associate
CCNA - Cisco Certified Network Associate
CCNA - Exam Information
The first step in becoming a Cisco Guru, is to take and pass the CCNA exam. The exam to take and pass to become a Cisco Certified Network Associate has changed throughout the years. The most recent update to this exam was the update from the 640-607 version to the 640-801 version. The 640-607 has been officially retired and is no longer a choice for this exam.
CCNA - Exam Details
The passing score in the past had been posted by Cisco and at one time was in the upper 800’s to pass, however they no longer publish what the official passing score is. The exam consists of 55 to 65 questions including multiple choice, drag and drop, and a few simulation questions throughout the exam. You will have a total of 90 minutes to complete this exam. The following are topics that will be included on the current CCNA exam. (Provided by Cisco)
Planning & Designing
Design a simple LAN using Cisco Technology
Design an IP addressing scheme to meet design requirements
Select an appropriate routing protocol based on user requirements
Design a simple internetwork using Cisco technology
Develop an access list to meet user specifications
Choose WAN services to meet customer requirements
Implementation & Operation
Configure routing protocols given user requirements
Configure IP addresses, subnet masks, and gateway addresses on routers and hosts
Configure a router for additional administrative functionality
Configure a switch with VLANS and inter-switch communication
Implement a LAN
Customize a switch configuration to meet specified network requirements
Manage system image and device configuration files
Perform an initial configuration on a router
Perform an initial configuration on a switch
Implement access lists
Implement simple WAN protocols
Troubleshooting
Utilize the OSI model as a guide for systematic network troubleshooting
Perform LAN and VLAN troubleshooting
Troubleshoot routing protocols
Troubleshoot IP addressing and host configuration
Troubleshoot a device as part of a working network
Troubleshoot an access list
Perform simple WAN troubleshooting
Technology
Describe network communications using layered models
Describe the Spanning Tree process
Compare and contrast key characteristics of LAN environments
Evaluate the characteristics of routing protocols
Evaluate TCP/IP communication process and its associated protocols
Describe the components of network devices
Evaluate rules for packet control
Evaluate key characteristics of WANs
The first step in becoming a Cisco Guru, is to take and pass the CCNA exam. The exam to take and pass to become a Cisco Certified Network Associate has changed throughout the years. The most recent update to this exam was the update from the 640-607 version to the 640-801 version. The 640-607 has been officially retired and is no longer a choice for this exam.
CCNA - Exam Details
The passing score in the past had been posted by Cisco and at one time was in the upper 800’s to pass, however they no longer publish what the official passing score is. The exam consists of 55 to 65 questions including multiple choice, drag and drop, and a few simulation questions throughout the exam. You will have a total of 90 minutes to complete this exam. The following are topics that will be included on the current CCNA exam. (Provided by Cisco)
Planning & Designing
Design a simple LAN using Cisco Technology
Design an IP addressing scheme to meet design requirements
Select an appropriate routing protocol based on user requirements
Design a simple internetwork using Cisco technology
Develop an access list to meet user specifications
Choose WAN services to meet customer requirements
Implementation & Operation
Configure routing protocols given user requirements
Configure IP addresses, subnet masks, and gateway addresses on routers and hosts
Configure a router for additional administrative functionality
Configure a switch with VLANS and inter-switch communication
Implement a LAN
Customize a switch configuration to meet specified network requirements
Manage system image and device configuration files
Perform an initial configuration on a router
Perform an initial configuration on a switch
Implement access lists
Implement simple WAN protocols
Troubleshooting
Utilize the OSI model as a guide for systematic network troubleshooting
Perform LAN and VLAN troubleshooting
Troubleshoot routing protocols
Troubleshoot IP addressing and host configuration
Troubleshoot a device as part of a working network
Troubleshoot an access list
Perform simple WAN troubleshooting
Technology
Describe network communications using layered models
Describe the Spanning Tree process
Compare and contrast key characteristics of LAN environments
Evaluate the characteristics of routing protocols
Evaluate TCP/IP communication process and its associated protocols
Describe the components of network devices
Evaluate rules for packet control
Evaluate key characteristics of WANs
Tuesday, January 8, 2008
Retired Certifications
Over time, as technologies change and products are made obselete, some certifications are retired. Retired certifications are no longer valid.
Certifications that fall into this category are listed below.
Business Ready Teleworker Solution Fundamentals
CCDP SNA/IP Integration
CCDP WAN Sw
CCIP Cable
CCIP Content Networking
CCIP DSL Networks
CCIP MPLS
CCIP Metro
CCIP Packet Telephony
CCIP Security
CCNA WAN Sw
CCNP LAN ATM
CCNP Network Management
CCNP SNA/IP Integration
CCNP Security
CCNP VOICE Access
CCNP WAN Sw Certification
Cable Communications for Account Managers
Certification Test-Understanding PBX Systems and Technology - VOD
Cisco ATP Optical Metro Transport AM/EM - Japanese
Cisco Access Routing & LAN Switching Sales Specialist
Cisco Access Routing & LAN Switching Specialist
Cisco Cable Communications Sales Spec
Cisco Cable Communications Sales Specialist
Cisco Cable Communications Specialist
Cisco Call Manager Express Specialist
Cisco Content Networking Sales Specialist
Cisco Content Networking Specialist
Cisco Content Networking Specialization Exam for SE's and FE's
Cisco Customer Contact Support - Retired
Cisco Firewall Specialist - Net Academy
Cisco IDS Specialist
Cisco IP Communications Support Specialist
Cisco IP Telephony
Cisco IP Telephony Express Spec
Cisco IP Telephony Express Specialist
Cisco IP Telephony Operations Specialist
Cisco IP Telephony-Enterprise Voice Over Data Design
Cisco IP Telephony-Installation, Support and Maintenance
Cisco Internet Solutions Specialist
Cisco Multiservice Switching Specialist
Cisco MxU Specialist
Cisco Network Management Sales Specialist
Cisco Network Management Specialist
Cisco Network Management Specialist
Cisco Optical Specialist
Cisco Partner and Solutions Essentials for Account Managers 5.2
Cisco Partner and Solutions Essentials for Enterprise Account Manager 6.0 - Latin American
Cisco Products Solutions Essentials 7.0
Cisco Products Solutions Essentials 8.0
Cisco Public Access Design Specialist
Cisco Public Access Support Specialist
Cisco Remote Dial Access: Voice and Data Specialization for AM's
Cisco Sales Expert v1
Cisco Sales Expert v2
Cisco Security Specialist 1
Cisco Storage Networking Design Specialist
Cisco Storage Networking Support Specialist
Cisco VPN/Security Sales Specialist
Cisco Voice Over Frame Relay
Cisco Wireless LAN Design Specialist
Cisco Wireless LAN Sales Spec
Cisco Wireless LAN Sales Specialist
Cisco Wireless LAN Support Specialist
Converged Business Solution Integration
DSL Specialization for Account Managers
DSL Specialization for SE's and FE's
EMEA SME v1.0
Enterprise
Enterprise - Japanese Language Version
Enterprise Skills Assessment
Enterprise for Account Managers
IPT Telephony Troubleshooting
Information Systems Security (INFOSEC) Professional
Network Management Specialization
Network Management for Account Managers
Network Mgt.
Open Programmable Switching Engineer
PBX Fundamentals
QoS
SCM Operation and Maintenance
SNA/IP Design Specialist
SNA/IP Solutions
SNA/IP Support Specialist
SNA/IP for Systems Engineers
Security Solutions
Selling AVVID Architecture
Small-to-Medium Business
Switched WAN Solutions for the Enterprise
Unity
Unity Engineer Specialization
Unity Engineer Specialization v1.1
Voice Solutions for Account Managers
Voice Solutions for System Engineers
Wireless LAN for Account Managers
Wireless LAN for SEs
Wireless LAN for SEs and FEs
Over time, as technologies change and products are made obselete, some certifications are retired. Retired certifications are no longer valid.
Certifications that fall into this category are listed below.
Business Ready Teleworker Solution Fundamentals
CCDP SNA/IP Integration
CCDP WAN Sw
CCIP Cable
CCIP Content Networking
CCIP DSL Networks
CCIP MPLS
CCIP Metro
CCIP Packet Telephony
CCIP Security
CCNA WAN Sw
CCNP LAN ATM
CCNP Network Management
CCNP SNA/IP Integration
CCNP Security
CCNP VOICE Access
CCNP WAN Sw Certification
Cable Communications for Account Managers
Certification Test-Understanding PBX Systems and Technology - VOD
Cisco ATP Optical Metro Transport AM/EM - Japanese
Cisco Access Routing & LAN Switching Sales Specialist
Cisco Access Routing & LAN Switching Specialist
Cisco Cable Communications Sales Spec
Cisco Cable Communications Sales Specialist
Cisco Cable Communications Specialist
Cisco Call Manager Express Specialist
Cisco Content Networking Sales Specialist
Cisco Content Networking Specialist
Cisco Content Networking Specialization Exam for SE's and FE's
Cisco Customer Contact Support - Retired
Cisco Firewall Specialist - Net Academy
Cisco IDS Specialist
Cisco IP Communications Support Specialist
Cisco IP Telephony
Cisco IP Telephony Express Spec
Cisco IP Telephony Express Specialist
Cisco IP Telephony Operations Specialist
Cisco IP Telephony-Enterprise Voice Over Data Design
Cisco IP Telephony-Installation, Support and Maintenance
Cisco Internet Solutions Specialist
Cisco Multiservice Switching Specialist
Cisco MxU Specialist
Cisco Network Management Sales Specialist
Cisco Network Management Specialist
Cisco Network Management Specialist
Cisco Optical Specialist
Cisco Partner and Solutions Essentials for Account Managers 5.2
Cisco Partner and Solutions Essentials for Enterprise Account Manager 6.0 - Latin American
Cisco Products Solutions Essentials 7.0
Cisco Products Solutions Essentials 8.0
Cisco Public Access Design Specialist
Cisco Public Access Support Specialist
Cisco Remote Dial Access: Voice and Data Specialization for AM's
Cisco Sales Expert v1
Cisco Sales Expert v2
Cisco Security Specialist 1
Cisco Storage Networking Design Specialist
Cisco Storage Networking Support Specialist
Cisco VPN/Security Sales Specialist
Cisco Voice Over Frame Relay
Cisco Wireless LAN Design Specialist
Cisco Wireless LAN Sales Spec
Cisco Wireless LAN Sales Specialist
Cisco Wireless LAN Support Specialist
Converged Business Solution Integration
DSL Specialization for Account Managers
DSL Specialization for SE's and FE's
EMEA SME v1.0
Enterprise
Enterprise - Japanese Language Version
Enterprise Skills Assessment
Enterprise for Account Managers
IPT Telephony Troubleshooting
Information Systems Security (INFOSEC) Professional
Network Management Specialization
Network Management for Account Managers
Network Mgt.
Open Programmable Switching Engineer
PBX Fundamentals
QoS
SCM Operation and Maintenance
SNA/IP Design Specialist
SNA/IP Solutions
SNA/IP Support Specialist
SNA/IP for Systems Engineers
Security Solutions
Selling AVVID Architecture
Small-to-Medium Business
Switched WAN Solutions for the Enterprise
Unity
Unity Engineer Specialization
Unity Engineer Specialization v1.1
Voice Solutions for Account Managers
Voice Solutions for System Engineers
Wireless LAN for Account Managers
Wireless LAN for SEs
Wireless LAN for SEs and FEs
Retired CCIE tracks
Retired CCIE tracks
Some previously awarded CCIE specialisations are no longer offered, and have been retired by Cisco. These are:
WAN Switching CCIE (Essentially a specialisation focusing on the IGX/BPX switch products, which had been acquired as part of the StrataCom aquisition)
ISP Dial CCIE
SNA/IP Integration CCIE (aka CCIE Blue)
Design CCIE
WAN Switching CCIE (Essentially a specialisation focusing on the IGX/BPX switch products, which had been acquired as part of the StrataCom aquisition)
ISP Dial CCIE
SNA/IP Integration CCIE (aka CCIE Blue)
Design CCIE
CCIE Storage Networking
CCIE Storage Networking
The latest addition to the CCIE certification tracks is the CCIE Storage Networking track. As the name suggests, the Storage Networking track concentrates on storage networking topics, such as Fibre Channel, iSCSI, FCIP, Intra VSAN Routing and FICON.
CCIE Voice
CCIE Voice
The Voice track concentrates on voice solutions for the enterprise and includes subjects such as QoS, MGCP, Call Manager (Cisco's VoIP PBX), Cisco Unity (Cisco's Unified Messaging platform), Unity Express and IP Contact Center Express.
CCIE Service Provider
CCIE Service Provider
The Service Provider track focuses on networking in the service provider industry. Subjects include Optical networks, DSL, WAN switching, Voice over IP, Content Networking, Broadband Cable and Metro Ethernet.
CCIE Security
CCIE Security
The Security track concentrates on network security and covers subjects such as ASA, IDS, IOS security, security and many others
Expert-level certifications
Expert-level certifications
The expert-level certification is the Cisco Certified Internetwork Expert (CCIE). It is the highest level of professional certification that Cisco provides. There are 5 active CCIE tracks, as shown below. As of November 14, 2007 there are 15,658 people with active CCIE certifications in the world.[11].
Cisco began its CCIE program in 1993[12] originally with a two day lab, later changing it to the one day format used today. Less than 3% of Cisco certified individuals attain CCIE certification, and on average will spend thousands of dollars and 18 months studying before passing.[13] Many candidates build mock-labs at home using old Cisco equipment, selling it again to other candidates after passing. Alternatively candidates may rent "rack time" online and practice lab scenarios on Cisco equipment hosted on the Internet for that purpose.
Cisco refers to the CCIE as the "most respected IT certification",[14] and from 2002 to 2005[15] it was voted as such in CertCities magazine. It has also been voted the most technically advanced IT certification by CertMag,[16] and is generally reported as the highest salaried certification in IT salary surveys.
The CCIE is comprised of a written exam and a "lab" exam (each in the specific area of the chosen track). The written exam is required to take the lab exam, and has a cost of $315[2] USD per attempt. Upon passing the written exam, the candidate is qualified to have a first attempt the lab exam for 18 months. If the first attempt is unsuccessful the candidate has 3 years from the date the written exam was passed to successfully complete the lab. If a candidate does not pass the CCIE lab in that time, they must pass the CCIE written exam again before making additional attempts at the CCIE lab exam. As many attempts can be made to pass the lab exam for up to 3 years after passing the written, so long as the first attempt is within 18 months. There is a minimum waiting time between attempts of one month.
The CCIE Lab is currently $1,400 USD[2] per attempt and are offered only at ten Cisco lab exam locations worldwide. The locations are Bangalore; Beijing; Brussels; Dubai; Hong Kong; Research Triangle Park, NC; San Jose, CA; São Paulo; Sydney; and Tokyo. In addition, according to a survey by Cisco the average cost to prepare for CCIE certification is $9,050 as of April 2006, spent mostly on practice equipment and self study material.[17] This is partially offset by the increased salary the certification commands, which a March 2007 Network World article estimates at 10% - 15% over similarly experienced engineers who do not have a CCIE.[18]
The lab is an 8-hour hands-on exam designed to demonstrate that the candidate not only knows the theory, but is also able to practice it. Many prospective CCIEs need multiple attempts to pass the lab exam.
There are no formal prerequisites for the CCIE exam, but Cisco recommends one has at least 3 - 5 years experience in networking before attempting to become a CCIE. CCIE was the first Cisco Certified qualification, and as such there were no other certifications that could be taken prior. The development of the associate and professional certifications was due to recognition of the fact that a CCIE is overkill for many networking personnel, and also for the vast majority of businesses who employ such people, and that certifications needed to be offered at lower levels. Despite the development of the lower certifications, Cisco has chosen not to make them formal requirements for the CCIE certification.
It is possible to hold multiple CCIE certifications. This is done by passing both the written and the lab exam in a particular track. As of November 14th, 2007 there are 1,344 individuals who hold multiple CCIE certifications. Of those, 210 hold three or more CCIE certifications.[19]
[edit] CCIE Routing & Switching
Routing and Switching is by far the most popular track with 14,329 certified individuals as of November 14th, 2007[20]. The certification covers a variety of networking concepts and protocols including but not limited to the following list [21]:
Bridging and Switching
Frame Relay
Ethernet
Catalyst Switch Configuration
IP Interior Gateway Routing Protocols
Open Shortest Path First (OSPF)
Enhanced Interior Gateway Routing Protocol (EIGRP)
Routing Information Protocol v2 (RIPv2)
Routing Information Protocol Next Generation (RIPng) - IPv6
Open Shortest Path First v3 (OSPFv3) - IPv6
On-Demand Routing (ODR)
Filtering, Summarization, Redistribution
Border Gateway Protocol (BGP)
iBGP
eBGP
Filtering, Summarization, Redistribution, and Traffic Engineering
Multicast Routing
Protocol Independent Multicast (PIM)
Multicast Source Discovery Protocol (MSDP)
Distance Vector Multicast Routing Protocol (DVMRP)
Anycast
Quality of Service (QoS)
Classification
Congestion Management and Avoidance
Policing and Shaping
Signaling
Security
Authentication, Authorization, and Accounting (AAA)
Traffic Filtering
IOS Firewall Feature Set
Access Lists
Routing Protocol and Catalyst Security
IP and IOS Features
IP addressing
Dynamic Host Configuration Protocol (DHCP)
Next Hop Redundancy Protocols (HSRP, VRRP, GLBP)
IP services
IOS user interfaces
System management
Network Address Translation (NAT)
Network Time Protocol (NTP)
Simple Network Management Protocol (SNMP)
Remote Monitoring (RMON)
IP Accounting
Service Level Agreement (SLA)
Cisco began its CCIE program in 1993[12] originally with a two day lab, later changing it to the one day format used today. Less than 3% of Cisco certified individuals attain CCIE certification, and on average will spend thousands of dollars and 18 months studying before passing.[13] Many candidates build mock-labs at home using old Cisco equipment, selling it again to other candidates after passing. Alternatively candidates may rent "rack time" online and practice lab scenarios on Cisco equipment hosted on the Internet for that purpose.
Cisco refers to the CCIE as the "most respected IT certification",[14] and from 2002 to 2005[15] it was voted as such in CertCities magazine. It has also been voted the most technically advanced IT certification by CertMag,[16] and is generally reported as the highest salaried certification in IT salary surveys.
The CCIE is comprised of a written exam and a "lab" exam (each in the specific area of the chosen track). The written exam is required to take the lab exam, and has a cost of $315[2] USD per attempt. Upon passing the written exam, the candidate is qualified to have a first attempt the lab exam for 18 months. If the first attempt is unsuccessful the candidate has 3 years from the date the written exam was passed to successfully complete the lab. If a candidate does not pass the CCIE lab in that time, they must pass the CCIE written exam again before making additional attempts at the CCIE lab exam. As many attempts can be made to pass the lab exam for up to 3 years after passing the written, so long as the first attempt is within 18 months. There is a minimum waiting time between attempts of one month.
The CCIE Lab is currently $1,400 USD[2] per attempt and are offered only at ten Cisco lab exam locations worldwide. The locations are Bangalore; Beijing; Brussels; Dubai; Hong Kong; Research Triangle Park, NC; San Jose, CA; São Paulo; Sydney; and Tokyo. In addition, according to a survey by Cisco the average cost to prepare for CCIE certification is $9,050 as of April 2006, spent mostly on practice equipment and self study material.[17] This is partially offset by the increased salary the certification commands, which a March 2007 Network World article estimates at 10% - 15% over similarly experienced engineers who do not have a CCIE.[18]
The lab is an 8-hour hands-on exam designed to demonstrate that the candidate not only knows the theory, but is also able to practice it. Many prospective CCIEs need multiple attempts to pass the lab exam.
There are no formal prerequisites for the CCIE exam, but Cisco recommends one has at least 3 - 5 years experience in networking before attempting to become a CCIE. CCIE was the first Cisco Certified qualification, and as such there were no other certifications that could be taken prior. The development of the associate and professional certifications was due to recognition of the fact that a CCIE is overkill for many networking personnel, and also for the vast majority of businesses who employ such people, and that certifications needed to be offered at lower levels. Despite the development of the lower certifications, Cisco has chosen not to make them formal requirements for the CCIE certification.
It is possible to hold multiple CCIE certifications. This is done by passing both the written and the lab exam in a particular track. As of November 14th, 2007 there are 1,344 individuals who hold multiple CCIE certifications. Of those, 210 hold three or more CCIE certifications.[19]
[edit] CCIE Routing & Switching
Routing and Switching is by far the most popular track with 14,329 certified individuals as of November 14th, 2007[20]. The certification covers a variety of networking concepts and protocols including but not limited to the following list [21]:
Bridging and Switching
Frame Relay
Ethernet
Catalyst Switch Configuration
IP Interior Gateway Routing Protocols
Open Shortest Path First (OSPF)
Enhanced Interior Gateway Routing Protocol (EIGRP)
Routing Information Protocol v2 (RIPv2)
Routing Information Protocol Next Generation (RIPng) - IPv6
Open Shortest Path First v3 (OSPFv3) - IPv6
On-Demand Routing (ODR)
Filtering, Summarization, Redistribution
Border Gateway Protocol (BGP)
iBGP
eBGP
Filtering, Summarization, Redistribution, and Traffic Engineering
Multicast Routing
Protocol Independent Multicast (PIM)
Multicast Source Discovery Protocol (MSDP)
Distance Vector Multicast Routing Protocol (DVMRP)
Anycast
Quality of Service (QoS)
Classification
Congestion Management and Avoidance
Policing and Shaping
Signaling
Security
Authentication, Authorization, and Accounting (AAA)
Traffic Filtering
IOS Firewall Feature Set
Access Lists
Routing Protocol and Catalyst Security
IP and IOS Features
IP addressing
Dynamic Host Configuration Protocol (DHCP)
Next Hop Redundancy Protocols (HSRP, VRRP, GLBP)
IP services
IOS user interfaces
System management
Network Address Translation (NAT)
Network Time Protocol (NTP)
Simple Network Management Protocol (SNMP)
Remote Monitoring (RMON)
IP Accounting
Service Level Agreement (SLA)
Cisco Certified Voice Professional (CCVP)
The CCVP is a certification covering all aspects of IP Telephony/VOIP networks and applications.
To attain this certification, five tests must be passed in the areas of Quality of service, Cisco VoIP, IP Telephony Troubleshooting, Cisco IP Telephony, and Gateway Gatekeeper.
To attain this certification, five tests must be passed in the areas of Quality of service, Cisco VoIP, IP Telephony Troubleshooting, Cisco IP Telephony, and Gateway Gatekeeper.
Cisco Certified Security Professional (CCSP)
Cisco Certified Security Professional (CCSP)
The CCSP certification is an advanced network security certification. Candidates for the certification are tested for advanced knowledge of various Cisco security products.
To attain this certification several tests must be passed in the areas of VPN, IDS, PIX firewall, Secure IOS, the Cisco SAFE, as well as having a CCNA or higher level certification (e.g. CCNP or CCIP).
The common practice is to take five exams which include one elective paper. The list of exams and elective papers can be found in the Cisco website.
To attain this certification several tests must be passed in the areas of VPN, IDS, PIX firewall, Secure IOS, the Cisco SAFE, as well as having a CCNA or higher level certification (e.g. CCNP or CCIP).
The common practice is to take five exams which include one elective paper. The list of exams and elective papers can be found in the Cisco website.
Cisco Certified Internetwork Professional (CCIP)
Cisco Certified Internetwork Professional (CCIP)
The CCIP certification is a professional certification covering the end-to-end protocols used in large scale networks.
To attain this certification tests must be passed in the areas of routing, BGP, MPLS and Quality of service
To attain this certification tests must be passed in the areas of routing, BGP, MPLS and Quality of service
Cisco Certified Design Professional (CCDP)
Cisco Certified Design Professional (CCDP)
The CCDP certification is an advanced network design certification provided by Cisco Systems, Inc. Candidates for the certification are tested for advanced knowledge of Cisco devices and the way to interconnect them. This certification is considered a professional level certificate by Cisco Systems. (The CCNA and CCDA are prerequisite.
The CCDP certification is an advanced network design certification provided by Cisco Systems, Inc. Candidates for the certification are tested for advanced knowledge of Cisco devices and the way to interconnect them. This certification is considered a professional level certificate by Cisco Systems. (The CCNA and CCDA are prerequisite.
Professional certifications
Professional certifications
Cisco Certified Network Professional (CCNP)
The CCNP is considered proof of having the ability to work with medium-sized networks (between 100 and 500 end devices) and with technology such as QoS, broadband, VPNs, and security-minded features. To acquire a CCNP one must possess a CCNA certification first and then pass three or four tests, depending on the path one chooses. The four tests path requires the candidate to pass the following tests:
642-901 BSCI: Building Scalable Cisco Internetworks (BSCI)[5]
642-812 BCMSN: Building Cisco Multilayer Switched Networks (BCMSN)[6]
642-825 ISCW: Implementing Secure Converged Wide Area Networks (ISCW)[7]
642-845 ONT: Optimizing Converged Cisco Networks (ONT)[8]
The BSCI and BCMSN tests can be taken as one single composite test known as the 642-892 Composite[9] which covers subjects for Building Scalable Cisco Internetworks (BSCI) and Building Cisco Multilayer Switched Networks (BCMSN).
In order to retain the certification one must either re-certify or upgrade to a CCIE every three years. Additional resources and tools to aid in preparing for the certification are available on the CCNP Prep Center.[10]
Cisco Certified Network Professional (CCNP)
The CCNP is considered proof of having the ability to work with medium-sized networks (between 100 and 500 end devices) and with technology such as QoS, broadband, VPNs, and security-minded features. To acquire a CCNP one must possess a CCNA certification first and then pass three or four tests, depending on the path one chooses. The four tests path requires the candidate to pass the following tests:
642-901 BSCI: Building Scalable Cisco Internetworks (BSCI)[5]
642-812 BCMSN: Building Cisco Multilayer Switched Networks (BCMSN)[6]
642-825 ISCW: Implementing Secure Converged Wide Area Networks (ISCW)[7]
642-845 ONT: Optimizing Converged Cisco Networks (ONT)[8]
The BSCI and BCMSN tests can be taken as one single composite test known as the 642-892 Composite[9] which covers subjects for Building Scalable Cisco Internetworks (BSCI) and Building Cisco Multilayer Switched Networks (BCMSN).
In order to retain the certification one must either re-certify or upgrade to a CCIE every three years. Additional resources and tools to aid in preparing for the certification are available on the CCNP Prep Center.[10]
Cisco Certified Design Associate (CCDA)
Cisco Certified Design Associate (CCDA)
The CCDA certification indicates an apprentice knowledge of Cisco network design. Individuals who have earned a CCDA are capable of designing switched or routed networks consisting of LANs, WANs, and various dial services. While a CCNA certification is not required to take the CCDA exam, Cisco recommends being familiar with CCNA material.
The CCDA certification indicates an apprentice knowledge of Cisco network design. Individuals who have earned a CCDA are capable of designing switched or routed networks consisting of LANs, WANs, and various dial services. While a CCNA certification is not required to take the CCDA exam, Cisco recommends being familiar with CCNA material.
Associate certifications
Associate certifications
Candidates have the option of gaining the certification by passing two tests (ICND1 640-822 and ICND2 640-816), or one single test (CCNA 640-802); the two-test option has the advantage of allowing the candidate to focus on certain subjects.[1]
The certification is valid for three years; at that time a CCNA holder must either
re-take the CCNA or ICND exam, or
take and pass an exam for one of the Professional (e.g., CCNP) or Specialist level certifications (excluding the sales specialist exams), or pass the CCIE written exam.
These exams are known by their corresponding numbers. When the curriculum of the exam changes the exam number also changes. The current exam number for CCNA is 640-802 (from 15 Aug 2007). The exam number for INTRO is 640-821 (Last day to test 11/6/07) and ICND the exam number is 640-811 (Last day to test 11/6/07). New ICND Part1 (640-822 ICND1) and ICND Part2 (640-816 ICND2) available from 15 Aug 2007. These exams are conducted by authorized test centers at a cost of $125 each for the INTRO or ICND exams and $150[2] for the full CCNA exam.
There is also the Cisco Networking Academy, which brings the CCNA and CCNP curricula into traditional educational institutions in over 150 countries.[3] Students enrolled in Cisco Networking Academy can request exam vouchers that allow them to take the retired exam for an extended period of time.[4]
Candidates have the option of gaining the certification by passing two tests (ICND1 640-822 and ICND2 640-816), or one single test (CCNA 640-802); the two-test option has the advantage of allowing the candidate to focus on certain subjects.[1]
The certification is valid for three years; at that time a CCNA holder must either
re-take the CCNA or ICND exam, or
take and pass an exam for one of the Professional (e.g., CCNP) or Specialist level certifications (excluding the sales specialist exams), or pass the CCIE written exam.
These exams are known by their corresponding numbers. When the curriculum of the exam changes the exam number also changes. The current exam number for CCNA is 640-802 (from 15 Aug 2007). The exam number for INTRO is 640-821 (Last day to test 11/6/07) and ICND the exam number is 640-811 (Last day to test 11/6/07). New ICND Part1 (640-822 ICND1) and ICND Part2 (640-816 ICND2) available from 15 Aug 2007. These exams are conducted by authorized test centers at a cost of $125 each for the INTRO or ICND exams and $150[2] for the full CCNA exam.
There is also the Cisco Networking Academy, which brings the CCNA and CCNP curricula into traditional educational institutions in over 150 countries.[3] Students enrolled in Cisco Networking Academy can request exam vouchers that allow them to take the retired exam for an extended period of time.[4]
Technician certifications
Technician certifications
The first stage of Cisco's certification system is the "Associate" level and begins with Cisco Certified Entry Networking Technician (CCENT) certification as an interim step to Associate level or directly with CCNA and CCDA certifications. The CCENT covers only basic networking knowledge, and does not get involved with the more technical aspects of the Cisco curriculum. The CCNA Discovery curriculum covers most of what is required to pass this exam.
Monday, January 7, 2008
Cisco Certification Capsule - CCNA, CCNP, CCIP, CCIE, CCSP, CCDP, CCDA Certifications information
Hi,This issue is a One Stop Guide for Cisco Certifications.
Cisco offers numerous certifications. We have compiled a Cisco Certification Path that you can check on our website at http://www.testswor ld.com/cisco/
Benefits of Cisco Certification
In general, Cisco Certification validates an individual's achievement, so it increases the holder's professional credibility by ensuring high standards of technical expertise.
You need to have CCNA for achieving higher Cisco Certifications
In particular, passing the CCNA test indicates knowledge of networking for small to big enterprises. It also confirms the ability to work in small businesses or organizations whose networks have fewer than 100 nodes.
How to Prepare for Cisco CertificationWe have compiled a Cisco Exam Study Kit that you can download from our website at http://www.testswor ld.com/cisco/
CCNA Certification Informationhttp://www.testswor ld.com/cisco/ ccna/?id= 19CCNP Certification Informationhttp://www.testswor ld.com/cisco/ ccnp/?id= 13 CCIP Certification Informationhttp://www.testswor ld.com/cisco/ ccip/?id= 14 CCIE Certification Informationhttp://www.testswor ld.com/cisco/ ccie/?id= 15 CCSP Certification Informationhttp://www.testswor ld.com/cisco/ ccsp?id=16 CCDP Certification Informationhttp://www.testswor ld.com/cisco/ ccdp/?id= 17 CCDA Certification Informationhttp://www.testswor ld.com/cisco/ ccda/?id= 18 Hope you enjoy our exams. Let us know what you think of our exams!
Cheers,
Team, TestsWorld.comhttp://www.testswor ld.com
Cisco offers numerous certifications. We have compiled a Cisco Certification Path that you can check on our website at http://www.testswor ld.com/cisco/
Benefits of Cisco Certification
In general, Cisco Certification validates an individual's achievement, so it increases the holder's professional credibility by ensuring high standards of technical expertise.
You need to have CCNA for achieving higher Cisco Certifications
In particular, passing the CCNA test indicates knowledge of networking for small to big enterprises. It also confirms the ability to work in small businesses or organizations whose networks have fewer than 100 nodes.
How to Prepare for Cisco CertificationWe have compiled a Cisco Exam Study Kit that you can download from our website at http://www.testswor ld.com/cisco/
CCNA Certification Informationhttp://www.testswor ld.com/cisco/ ccna/?id= 19CCNP Certification Informationhttp://www.testswor ld.com/cisco/ ccnp/?id= 13 CCIP Certification Informationhttp://www.testswor ld.com/cisco/ ccip/?id= 14 CCIE Certification Informationhttp://www.testswor ld.com/cisco/ ccie/?id= 15 CCSP Certification Informationhttp://www.testswor ld.com/cisco/ ccsp?id=16 CCDP Certification Informationhttp://www.testswor ld.com/cisco/ ccdp/?id= 17 CCDA Certification Informationhttp://www.testswor ld.com/cisco/ ccda/?id= 18 Hope you enjoy our exams. Let us know what you think of our exams!
Cheers,
Team, TestsWorld.comhttp://www.testswor ld.com
Sunday, January 6, 2008
Saturday, January 5, 2008
Cisco CCNA & CCNP - Suggestions On How To Build A Home Lab
Cisco CCNA & CCNP - Suggestions On How To Build A Home Lab
Many people ask me what would make a good CCNA lab? Well, that can be a tricky question based upon your budget and future Cisco aspirations. So let's start off with a few basic concepts I hope we can all agree on
Cisco Certifications For Networking Professionals
Cisco Certifications For Networking Professionals
In order to achieve the second tier of the Cisco Pyramid, one needs to pass the Cisco Certifications for Network Professionals exam. This exam will prove that a network professional will be able to install, configure, and troubleshoot converged local and wide area networks with one hundred to five hundred or more nodes.
Top 10 Certification Exam Tips
Getting Certification is a cherished vision for every person, who desires to be recognized as a certified professional in the IT industry. Industry experts advocate going for more and more certifications these days
Restoratives for a Happier Face
Restoratives for a Happier Face
It's not your fault, really. If you've got to blame someone, blame your ancestors. Chances are they came from someplace where oily skin served a useful purpose, such as combating the effects of excessive Mediterranean sunlight or monsoon rains. Now you're stuck with oily skin in the middle of Minnesota, where the embarrassment of a shiny forehead outweighs any possible protection your skin might afford you from scorching rays or tropical torrents.
Heredity does play a big part in oily skin, but so do hormones. Pregnant women sometimes notice an increase in skin oil as hormonal activity changes. So do women taking certain types of birth control pills. Stress can also cause the oil glands to kick into overdrive. The wrong cosmetics can easily aggravate an otherwise mild case of oily skin. Some of these causes are within your ability to control, but others you'll have to learn to live with.
There is no magic cure for oily skin. State-of-the- art advice from the experts calls for keeping it clean, and keeping at it all the time. Our tips will help you do that as well as it can be done.
On the up side, skin experts believe there are some advantages to having an oily hide, not the least of which becomes apparent with the steady passing of time. That is, oily skin tends to age better and wrinkle less than dry or normal skin. Today's curse; tomorrow's blessing.
Make mine mud. "Clay masks or mud masks are worthwhile," says Howard Donsky, M.D., an associate professor of medicine at the University of Toronto and staff dermatologist at Toronto General Hospital. But Dr. Donsky cautions that masks will make skin feel good and look better only temporarily, so don't count on the effects lasting for any length of time.
Generally, the darker brown the clay (mud), the more oil it can absorb. White or rose-colored clays, though, are gentler and work best on sensitive skin.
Masks can cleanse the skin of surface greasiness, but don't expect them to "deep-clean" the pores (the term is meaningless, some experts say) or do anything more than temporarily tone the skin.
Splash on the hot suds. "Hot water is a good solvent," says Hillard H. Pearlstein, M.D., a private practitioner and assistant clinical professor of dermatology at the Mount Sinai School of Medicine of the City University of New York. For that reason, he recommends that oily skin be washed in very warm water, with plenty of soap. "Hot water plus soap will dissolve skin oil better than cold water and soap," he says, "because more things dissolve in hot than cold, and that includes soap and the grit and grime you're trying to get rid of on your skin."
Seek out drying soaps. "Given the state of the art in oily skin treatment, all you can really do is degrease the skin," Dr. Pearlstein says, "and that has to be done repeatedly, with astringents and with drying soaps."
Finding a drying soap is not a problem (finding one that won't dry the skin can be, however). Many dermatologists seem to favor good old Ivory for oily skin, along with more specialized degreasing soaps such as Cuticura Mildly Medicated Soap, Clearasil soap, and Neutrogena Oily Skin Formula, to name a few.
But there's really no reason to spend lots of money, says Kenneth Neldner, M.D., a professor and chairman of the Department of Dermatology at the Texas Tech University Health Sciences Center School of Medicine. "Some people feel that soaps like Safeguard and Dial are fairly drying, and these should do the trick. The thing is to make sure you use lots of it—go heavy on the soap and scrub that skin."
Follow with astringents. Astringents with acetone are your best bet, according to Dr. Neldner. "Acetone is a great fat and grease solvent, and most astringents have a bit of acetone in them. If you use it regularly, you can surely remove oil from the skin."
Although most astringents contain alcohol, look for a brand that also contains acetones, such as Seba-Nil, says Dr .Neldner. Ordinary rubbing alcohol, however, can be used as an effective, inexpensive astringent. Those looking for something milder can try witch hazel, which contains some alcohol and also works well.
Nonalcohol astringents contain mostly water and are not as effective as those with alcohol and acetone, but they may be of help for those with sensitive skin. Worth noting: Dermatologists say that rather than washing the face several times a day, which can leave it too dry and irritated, you're better off to carry astringent pads with you and use them to cleanse the face.
Select cosmetics with care. "Cosmetics come in two major categories," says Dr. Neldner, "oil-based and water-based. If you've got oily skin, use only a water-based product."
There are many cosmetics formulated for oily skin. They are made to soak up and cover oiliness so the skin doesn't look as greasy. But no cosmetic has any magical ingredient that will slow down or stop oil production, so don't be lured into buying products that make such claims.
Take a powder. Baby powder, that is. For additional shine-free protection, some women find that simple products such as Johnson's Baby Powder make a superb face powder when fluffed lightly over makeup.
Heredity does play a big part in oily skin, but so do hormones. Pregnant women sometimes notice an increase in skin oil as hormonal activity changes. So do women taking certain types of birth control pills. Stress can also cause the oil glands to kick into overdrive. The wrong cosmetics can easily aggravate an otherwise mild case of oily skin. Some of these causes are within your ability to control, but others you'll have to learn to live with.
There is no magic cure for oily skin. State-of-the- art advice from the experts calls for keeping it clean, and keeping at it all the time. Our tips will help you do that as well as it can be done.
On the up side, skin experts believe there are some advantages to having an oily hide, not the least of which becomes apparent with the steady passing of time. That is, oily skin tends to age better and wrinkle less than dry or normal skin. Today's curse; tomorrow's blessing.
Make mine mud. "Clay masks or mud masks are worthwhile," says Howard Donsky, M.D., an associate professor of medicine at the University of Toronto and staff dermatologist at Toronto General Hospital. But Dr. Donsky cautions that masks will make skin feel good and look better only temporarily, so don't count on the effects lasting for any length of time.
Generally, the darker brown the clay (mud), the more oil it can absorb. White or rose-colored clays, though, are gentler and work best on sensitive skin.
Masks can cleanse the skin of surface greasiness, but don't expect them to "deep-clean" the pores (the term is meaningless, some experts say) or do anything more than temporarily tone the skin.
Splash on the hot suds. "Hot water is a good solvent," says Hillard H. Pearlstein, M.D., a private practitioner and assistant clinical professor of dermatology at the Mount Sinai School of Medicine of the City University of New York. For that reason, he recommends that oily skin be washed in very warm water, with plenty of soap. "Hot water plus soap will dissolve skin oil better than cold water and soap," he says, "because more things dissolve in hot than cold, and that includes soap and the grit and grime you're trying to get rid of on your skin."
Seek out drying soaps. "Given the state of the art in oily skin treatment, all you can really do is degrease the skin," Dr. Pearlstein says, "and that has to be done repeatedly, with astringents and with drying soaps."
Finding a drying soap is not a problem (finding one that won't dry the skin can be, however). Many dermatologists seem to favor good old Ivory for oily skin, along with more specialized degreasing soaps such as Cuticura Mildly Medicated Soap, Clearasil soap, and Neutrogena Oily Skin Formula, to name a few.
But there's really no reason to spend lots of money, says Kenneth Neldner, M.D., a professor and chairman of the Department of Dermatology at the Texas Tech University Health Sciences Center School of Medicine. "Some people feel that soaps like Safeguard and Dial are fairly drying, and these should do the trick. The thing is to make sure you use lots of it—go heavy on the soap and scrub that skin."
Follow with astringents. Astringents with acetone are your best bet, according to Dr. Neldner. "Acetone is a great fat and grease solvent, and most astringents have a bit of acetone in them. If you use it regularly, you can surely remove oil from the skin."
Although most astringents contain alcohol, look for a brand that also contains acetones, such as Seba-Nil, says Dr .Neldner. Ordinary rubbing alcohol, however, can be used as an effective, inexpensive astringent. Those looking for something milder can try witch hazel, which contains some alcohol and also works well.
Nonalcohol astringents contain mostly water and are not as effective as those with alcohol and acetone, but they may be of help for those with sensitive skin. Worth noting: Dermatologists say that rather than washing the face several times a day, which can leave it too dry and irritated, you're better off to carry astringent pads with you and use them to cleanse the face.
Select cosmetics with care. "Cosmetics come in two major categories," says Dr. Neldner, "oil-based and water-based. If you've got oily skin, use only a water-based product."
There are many cosmetics formulated for oily skin. They are made to soak up and cover oiliness so the skin doesn't look as greasy. But no cosmetic has any magical ingredient that will slow down or stop oil production, so don't be lured into buying products that make such claims.
Take a powder. Baby powder, that is. For additional shine-free protection, some women find that simple products such as Johnson's Baby Powder make a superb face powder when fluffed lightly over makeup.
Now, machine to read your mind
Now, machine to read your mind
LONDON: Scientists have developed a machine which is capable of reading our mind and revealing our most private thoughts. American researchers from Carnegie Mellon University in Pittsburgh found that with the aid of a sophisticated scanner and computer programme, they were able to determine how the brain lights up when thinking about different subjects. Using an advanced form of MRI scanner, they analysed how the brain reacted to ten drawings of tools and buildings. They then used a computer programme to work out whether a person was thinking about a tool or a building. "We hope to progress to identifying the thoughts associated not just with pictures but also with words and eventually sentences," said Dr Svetlana Shinkareva, one of the researchers. The device's possibilities can be extended and the team envisage a time when it will be used to conduct infallible lie detector tests, while the accurate interpretation of a person's intentions could allow police to arrest criminals before they break the law, as seen in the film Minority Report. The researchers' analysis was found to be 97 per cent accurate. Despite being limited to picking up the thoughts behind just ten pictures, the researchers are confident that they will soon be able to identify entire sentences. The study, published in the journal PLoS ONE , also showed that different people think about the same thing in the same way. "This part of the study establishes, as never before, that there is a commonality in how different people's brains represent the same subject," the study, reported in the Daily Mail of Britain, said.
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Home Beauty Tips
Home Beauty Tips
To remove puffiness from the eyelids, massage a drop of very fresh castor oil on to them. To cool your eyes, make eye pads using thick slices of cucumber. Another option is to use cotton pads soaked in cold milk. Lie down and place them on your closed eyes and relax for a while. Putting a drop of rose water into each eye just before you sleep can also refresh you eyes. To prevent your lips from chapping, use hot water fermentation on your lips and then apply a mixture of vaseline and honey. Apply this mixture about three times a week. To prevent your lips from drying you can use a ground mixture or rose petals and milk butter. To delay age spots on your hand, use a piece of lemon and rub all over your hand, before washing. This will delay onset of age-spots. If you have no time to shampoo your hair before going out, then brush 1 tablespoon of talcum powder or corn flour through your hair. Try this out first when you are not in hurry to make sure that it works the way you want. To prevent hair loss you should have a biotin rich drink. Blend bananas with honey, yogurt and low fat milk. Drink this for a few weeks. While blow drying and setting your hair, blow-dry at hot on the roots of the hair. Roll your hair inwards or outwards at the ends. To improve the setting make sure the ends are evenly rolled in or rolled out. Heat the hair for a second and then let it cool. This process of setting the hair will last longer and make your hair look beautiful. To condition your hair, after shampooing your hair take some conditioner on your palm and rub it with both hands. Apply from the hair shaft moving downwards. Do not apply on your scalp. Rinse your hair after 5 minutes. To add extra shine and glow to your hair add 2 tablespoons of malt vinegar. Use it as a last rinse and towel dry your hair.
Friday, January 4, 2008
orkut blocked.........no probs.......do the simple steps..:)))))))))))))
orkut blocked.........no probs.......do the simple steps..:)))))))))))))
this is for all those who cannot access orkut nd also cant open it thru kproxy.com.. .follow these following steps to open orkut....1.go to the url bar and type 66.232.117.2432.type just these numeric literals..witn no www or .com3.it vil open the site kproxy.com.. .{ without shutting down ur systems }4.now just type in www.orkut.com in the given box of kproxy.com nd enjoy orkut..
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The Complete Guide To Optimising Windows XP
The Complete Guide To Optimising Windows XP
Beginners
Remove Annoying Delete Confirmation MessagesAlthough not strictly a performance tweak I love this fix as it makes my machine 'feel' faster. I hate the annoying 'are you sure?' messages that XP displays, especially if I have to use a laptop touchpad to close them. To remove these messages:
Right-click on the 'Recycle Bin' on the desktop and then click 'Properties'
Clear the 'Display Delete Confirmation Dialog' check box and click 'Ok'. If you do accidentally delete a file don't worry as all is not lost. Just go to your Recycle Bin and 'Restore' the file.
Disable Indexing ServicesIndexing Services is a small little program that uses large amounts of RAM and can often make a computer endlessly loud and noisy. This system process indexes and updates lists of all the files that are on your computer. It does this so that when you do a search for something on your computer, it will search faster by scanning the index lists. If you don't search your computer often, or even if you do search often, this system service is completely unnecessary. To disable do the following:
Go to Start
Click Settings
Click Control Panel
Double-click Add/Remove Programs
Click the Add/Remove Window Components
Uncheck the Indexing services box
Click 'Next'
Optimise Display SettingsWindows XP can look sexy but displaying all the visual items can waste system resources. To optimise:
Go to Start
Click Settings
Click Control Panel
Click System
Click Advanced tab
In the Performance tab click Settings
Leave only the following ticked:
Show shadows under menus
Show shadows under mouse pointer
Show translucent selection rectangle
Use drop shadows for icons labels on the desktop
Use visual styles on windows and buttons
Speedup Folder BrowsingYou may have noticed that every-time you open my computer to browse folders that there is a slight delay. This is because Windows XP automatically searches for network files and printers every-time you open Windows Explorer. To fix this and to increase browsing significantly:
Open My Computer
Click on Tools menu
Click on Folder Options
Click on the View tab.
Uncheck the Automatically search for network folders and printers check box
Click Apply
Click Ok
Reboot your computer
Disable Performance CountersWindows XP has a performance monitor utility which monitors several areas of your PC's performance. These utilities take up system resources so disabling is a good idea. To disable:
download and install the Extensible Performance Counter List
Then select each counter in turn in the 'Extensible performance counters' window and clear the 'performance counters enabled' checkbox at the bottom.button below
Improve Memory Usage With Cacheman
Cacheman Improves the performance of your computer by optimizing the disk cache, memory and a number of other settings. Once Installed:
Go to Show Wizard and select All
Run all the wizards by selecting Next or Finished until you are back to the main menu. Use the defaults unless you know exactly what you are doing
Exit and Save Cacheman
Restart Windows
Optimise your internet connection
There are lots of ways to do this but by far the easiest is to run TCP/IP Optimizer
Download and install
Click the General Settings tab and select your Connection Speed (Kbps)
Click Network Adapter and choose the interface you use to connect to the Internet
Check Optimal Settings then Apply
Reboot
Optimise Your Pagefile
If you give your pagefile a fixed size it saves the operating system from needing to resize the page file.
Windows XP sizes the page file to about 1.5X the amount of actual physical memory by default. While this is good for systems with smaller amounts of memory (under 512MB) it is unlikely that a typical XP desktop system will ever need 1.5 X 512MB or more of virtual memory. If you have less than 512MB of memory, leave the page file at its default size. If you have 512MB or more, change the ratio to 1:1 page file size to physical memory size.
Right click on My Computer and select Properties
Select the Advanced tab
Under Performance choose the Settings button
Select the Advanced tab again and under Virtual Memory select Change
Highlight the drive containing your page file and make the initial Size of the file the same as the Maximum Size of the file.
Run BootVis - Improve Boot Times
BootVis will significantly improve boot times:
Download and Run
Select Trace
Select Next Boot and Driver Trace
A Trace Repetitions screen will appear, select Ok and Reboot
Upon reboot, BootVis will automatically start, analyze and log your system's boot process. When it's done, in the menu go to Trace and select Optimize System
Reboot.
When your machine has rebooted wait until you see the Optimizing System box appear. Be patient and wait for the process to complete
Remove Fonts for Speed
Fonts, especially TrueType fonts, use quite a bit of system resources. For optimal performance, trim your fonts down to just those that you need to use on a daily basis and fonts that applications may require.
Open Control Panel
Open Fonts folder
Move fonts you don't need to a temporary directory (e.g. C:¢DFONTBKUP?) just in case you need or want to bring a few of them back. The more fonts you uninstall, the more system resources you will gain.
Intermediate
Turn Off System Restore
System Restore can be a useful if your computer is having problems, however storing all the restore points can literally take up Gigabytes of space on your hard drive. To turn off System Restore:
Open Control Panel
Click on Performance and Maintenance
Click on System
Click on the System Restore tab
Tick 'Turn off System Restore on All Drives'
Click 'Ok'
Defragment Your Pagefile
Keeping your pagefile defragmented can provide a major performance boost. One of the best ways of doing this is to creat a separate partition on your hard drive just for your page file, so that it doesn't get impacted by normal disk usage. Another way of keeping your pagefile defragmented is to run PageDefrag. This cool little app can be used to defrag your pagefile, and can also be set to defrag the pagefile everytime your PC starts. To install:
Download and Run PageDefrag
Tick "Defrag at next Reboot",
Click "Ok"
Reboot
Make Your Menus Load Faster
This is one of my favourite tweaks as it makes a huge difference to how fast your machine will 'feel'. What this tweak does is remove the slight delay between clicking on a menu and XP displaying the menu.
This is the delay time before a menu is opened. You can set it to "0? but it can make windows really hard to use as menus will open if you just look at them - well move your mouse over them anyway. I tend to go for anywhere between 50-150 depending on my mood
Go to Start then Run
Type 'Regedit' then click 'Ok'
Find "HKEY_CURRENT_ USER¢DControl Panel¢DDesktop"
Select "MenuShowDelay"
Right click and select "Modify'
Reduce the number to around "100?
Make Programs Load Faster
This little tweak tends to work for most programs. If your program doesn't load properly just undo the change. For any program:
Right-click on the icon/shortcut you use to launch the program
Select properties
In the 'target' box, add ' /prefetch:1¡¬ at the end of the line.
Click "Ok"
Ensure XP Is Using DMA Mode
XP enables DMA for Hard-Drives and CD-Roms by default on most ATA or ATAPI (IDE) devices. However, sometimes computers switch to PIO mode which is slower for data transfer - a typical reason is because of a virus. To ensure that your machine is using DMA:
Open 'Device Manager'
Double-click 'IDE ATA/ATAPI Controllers'
Right-click 'Primary Channel' and select 'Properties' and then 'Advanced Settings'
In the 'Current Transfer Mode' drop-down box, select 'DMA if Available' if the current setting is 'PIO Only'
Advanced
Speed Up Boot Times I
This tweak works by creating a batch file to clear the temp and history folders everytime you shutdown so that your PC doesn't waste time checking these folders the next time it boots. It's quite simple to implement:
Open Notepad and create a new file with the following entries:
RD /S /q "C:¢DDocuments and Settings"UserName without quotes"¢DLocal Settings¢DHistory"
RD /S /q "C:¢DDocuments and Settings¢DDefault User¢DLocal Settings¢DHistory"
RD /S /q "D:¢DTemp" <¡V"Deletes temp folder, type in the location of your temp folder"
Save the new as anything you like but it has to be a '.bat' file e.g. fastboot.bat or deltemp.bat
Click 'Start' then 'Run'
Type in 'gpedit.msc' and hit 'ok'
Click on 'Computer Configuration' then 'Windows Settings'
Double-click on 'Scripts' and then on 'Shutdown'
Click 'Add' and find the batch file that you created and then press 'Ok'
Speed Up Boot Times II
When your PC starts it usually looks for any bootable media in any floppy or cd-rom drives you have installed before it gets around to loading the Operating System from the HDD. This can waste valuable time. To fix this we need to make some changes to the Bios.
Note: Once this change has been made, you won't be able to boot from a floppy disc or a CD-rom. If for some strange reason you need to do this in the future, just go back into your bios, repeat the steps above and put your floppy or CD-rom back as the 'First Device'
To enter the bios you usually press 'F2¡¬ or 'delete' when your PC starts
Navigate to the 'Boot' menu
Select 'Boot Sequence'
Then either move your Hard drive to the top position or set it as the 'First Device'5. Press the 'Escape' key to leave the bios. Don't forget to save your settings before exiting
Speed Up Boot Times III
When your computer boots up it usually has to check with the network to see what IP addresses are free and then it grabs one of these. By configuring a manually assigned IP address your boot time will improve. To do this do the following:
Click on 'Start' and then "Connect To/Show All Connections'
Right-click your network adapter card and click 'Properties'
On the 'General' tab, select 'TCP/IP' in the list of services and click 'Properties'
In the TCP/IP properties, click 'Use the following address' and enter an IP address for your PC. If you are using a router this is usually 192.168.0.xx or 192.168.1.xx. If you are not sure what address you could check with your ISP or go to 'Start/run' and type 'cmd' and then 'ipconfig/all' . This will show your current IP settings which you will need to copy
Enter the correct details for 'Subnet mask', 'Default gateway' and 'DNS Server'. Again if you are not sure what figures to enter use 'ipconfig/all' as in stage 4
Disable Unnecessary Services
Because Windows XP has to be all things to all people it has many services running that take up system resources that you will never need.Below is a list of services that can be disabled on most machines:
To disable these services:
Alerter
Clipbook
Computer Browser
Distributed Link Tracking Client
Fast User Switching
Help and Support - (If you use Windows Help and Support leave this enabled)
Indexing Service
IPSEC Services
Messenger
Netmeeting Remote Desktop Sharing (disabled for extra security)
Portable Media Serial Number
Remote Desktop Help Session Manager (disabled for extra security)
Remote Procedure Call Locator
Remote Registry (disabled for extra security)
Remote Registry Service
Secondary Logon
Routing & Remote Access (disabled for extra security)
Server
SSDP Discovery Service - (Unplug n' Pray will disable this)
Telnet
TCP/IP NetBIOS Helper
Upload Manager
Universal Plug and Play Device Host
Windows Time
Wireless Zero Configuration (Do not disable if you use a wireless network)
Go to Start and then Run and type "services.msc"
Doubleclick on the service you want to change
Change the startup type to 'Disable"
Speedup Folder Access - Disable Last Access Update
If you have a lot of folders and subdirectories on your computer, when you access a directory XP wastes a lot of time updating the time stamp showing the last access time for that directory and for ALL sub directories. To stop XP doing this you need to edit the registry. If you are uncomfortable doing this then please do not attempt.
Go to Start and then Run and type "regedit"
Click through the file system until you get to "HKEY_LOCAL_ MACHINE¢DSystem¢DCurrentControlS et¢DControl¢DFileSystem"
Right-click in a blank area of the window on the right and select 'DWORD Value'
Create a new DWORD Value called 'NtfsDisableLastAcc essUpdate'
Then Right click on the new value and select 'Modify'
Change the Value Data to '1¡¬
Click 'OK'
Improve Boot Times
A great new feature in Microsoft Windows XP is the ability to do a boot defragment. This places all boot files next to each other on the disk to allow for faster booting. By default this option in enables but on some builds it is not so below is how to turn it on.
Go to Start Menu and Click Run
Type in "Regedit" then click ok
Find "HKEY_LOCAL_ MACHINE¢DSOFTWARE¢DMicrosoft¢DDfrg¢DBootOpt imizeFunction"
Select "Enable" from the list on the right
Right on it and select "Modify"
Change the value to "Y to enable"
Reboot
Improve Swapfile Performance
If you have more than 256MB of RAM this tweak will considerably improve your performance. It basically makes sure that your PC uses every last drop of memory (faster than swap file) before it starts using the swap file.
Go to Start then Run
Type "msconfig.exe" then ok
Click on the System.ini tab
Expand the 386enh tab by clicking on the plus sign
Click on new then in the blank box type"ConservativeSw apfileUsage= 1?
Click OK
Restart PC
Improve XP Shutdown Speed
This tweak reduces the time XP waits before automatically closing any running programs when you give it the command to shutdown.
Go to Start then select Run
Type 'Regedit' and click ok
Find 'HKEY_CURRENT_ USER¢DControl Panel¢DDesktop'Select 'WaitToKillAppTimeo ut'
Right click and select 'Modify'
Change the value to '1000¡¬
Click 'OK'
Now select 'HungAppTimeout'
Right click and select 'Modify'
Change the value to '1000¡¬
Click 'OK'
Now find 'HKEY_USERS¢D.DEFAULT¢DControl Panel¢DDesktop'
Select 'WaitToKillAppTimeo ut'
Right click and select 'Modify'
Change the value to '1000¡¬
Click 'OK'
Now find 'HKEY_LOCAL_ MACHINE¢DSystem¢DCurrentControlS et¢DControl'
Select 'WaitToKillServiceT imeout'
Right click and select 'Modify'
Change the value to '1000¡¬
Click 'OK'
Beginners
Remove Annoying Delete Confirmation MessagesAlthough not strictly a performance tweak I love this fix as it makes my machine 'feel' faster. I hate the annoying 'are you sure?' messages that XP displays, especially if I have to use a laptop touchpad to close them. To remove these messages:
Right-click on the 'Recycle Bin' on the desktop and then click 'Properties'
Clear the 'Display Delete Confirmation Dialog' check box and click 'Ok'. If you do accidentally delete a file don't worry as all is not lost. Just go to your Recycle Bin and 'Restore' the file.
Disable Indexing ServicesIndexing Services is a small little program that uses large amounts of RAM and can often make a computer endlessly loud and noisy. This system process indexes and updates lists of all the files that are on your computer. It does this so that when you do a search for something on your computer, it will search faster by scanning the index lists. If you don't search your computer often, or even if you do search often, this system service is completely unnecessary. To disable do the following:
Go to Start
Click Settings
Click Control Panel
Double-click Add/Remove Programs
Click the Add/Remove Window Components
Uncheck the Indexing services box
Click 'Next'
Optimise Display SettingsWindows XP can look sexy but displaying all the visual items can waste system resources. To optimise:
Go to Start
Click Settings
Click Control Panel
Click System
Click Advanced tab
In the Performance tab click Settings
Leave only the following ticked:
Show shadows under menus
Show shadows under mouse pointer
Show translucent selection rectangle
Use drop shadows for icons labels on the desktop
Use visual styles on windows and buttons
Speedup Folder BrowsingYou may have noticed that every-time you open my computer to browse folders that there is a slight delay. This is because Windows XP automatically searches for network files and printers every-time you open Windows Explorer. To fix this and to increase browsing significantly:
Open My Computer
Click on Tools menu
Click on Folder Options
Click on the View tab.
Uncheck the Automatically search for network folders and printers check box
Click Apply
Click Ok
Reboot your computer
Disable Performance CountersWindows XP has a performance monitor utility which monitors several areas of your PC's performance. These utilities take up system resources so disabling is a good idea. To disable:
download and install the Extensible Performance Counter List
Then select each counter in turn in the 'Extensible performance counters' window and clear the 'performance counters enabled' checkbox at the bottom.button below
Improve Memory Usage With Cacheman
Cacheman Improves the performance of your computer by optimizing the disk cache, memory and a number of other settings. Once Installed:
Go to Show Wizard and select All
Run all the wizards by selecting Next or Finished until you are back to the main menu. Use the defaults unless you know exactly what you are doing
Exit and Save Cacheman
Restart Windows
Optimise your internet connection
There are lots of ways to do this but by far the easiest is to run TCP/IP Optimizer
Download and install
Click the General Settings tab and select your Connection Speed (Kbps)
Click Network Adapter and choose the interface you use to connect to the Internet
Check Optimal Settings then Apply
Reboot
Optimise Your Pagefile
If you give your pagefile a fixed size it saves the operating system from needing to resize the page file.
Windows XP sizes the page file to about 1.5X the amount of actual physical memory by default. While this is good for systems with smaller amounts of memory (under 512MB) it is unlikely that a typical XP desktop system will ever need 1.5 X 512MB or more of virtual memory. If you have less than 512MB of memory, leave the page file at its default size. If you have 512MB or more, change the ratio to 1:1 page file size to physical memory size.
Right click on My Computer and select Properties
Select the Advanced tab
Under Performance choose the Settings button
Select the Advanced tab again and under Virtual Memory select Change
Highlight the drive containing your page file and make the initial Size of the file the same as the Maximum Size of the file.
Run BootVis - Improve Boot Times
BootVis will significantly improve boot times:
Download and Run
Select Trace
Select Next Boot and Driver Trace
A Trace Repetitions screen will appear, select Ok and Reboot
Upon reboot, BootVis will automatically start, analyze and log your system's boot process. When it's done, in the menu go to Trace and select Optimize System
Reboot.
When your machine has rebooted wait until you see the Optimizing System box appear. Be patient and wait for the process to complete
Remove Fonts for Speed
Fonts, especially TrueType fonts, use quite a bit of system resources. For optimal performance, trim your fonts down to just those that you need to use on a daily basis and fonts that applications may require.
Open Control Panel
Open Fonts folder
Move fonts you don't need to a temporary directory (e.g. C:¢DFONTBKUP?) just in case you need or want to bring a few of them back. The more fonts you uninstall, the more system resources you will gain.
Intermediate
Turn Off System Restore
System Restore can be a useful if your computer is having problems, however storing all the restore points can literally take up Gigabytes of space on your hard drive. To turn off System Restore:
Open Control Panel
Click on Performance and Maintenance
Click on System
Click on the System Restore tab
Tick 'Turn off System Restore on All Drives'
Click 'Ok'
Defragment Your Pagefile
Keeping your pagefile defragmented can provide a major performance boost. One of the best ways of doing this is to creat a separate partition on your hard drive just for your page file, so that it doesn't get impacted by normal disk usage. Another way of keeping your pagefile defragmented is to run PageDefrag. This cool little app can be used to defrag your pagefile, and can also be set to defrag the pagefile everytime your PC starts. To install:
Download and Run PageDefrag
Tick "Defrag at next Reboot",
Click "Ok"
Reboot
Make Your Menus Load Faster
This is one of my favourite tweaks as it makes a huge difference to how fast your machine will 'feel'. What this tweak does is remove the slight delay between clicking on a menu and XP displaying the menu.
This is the delay time before a menu is opened. You can set it to "0? but it can make windows really hard to use as menus will open if you just look at them - well move your mouse over them anyway. I tend to go for anywhere between 50-150 depending on my mood
Go to Start then Run
Type 'Regedit' then click 'Ok'
Find "HKEY_CURRENT_ USER¢DControl Panel¢DDesktop"
Select "MenuShowDelay"
Right click and select "Modify'
Reduce the number to around "100?
Make Programs Load Faster
This little tweak tends to work for most programs. If your program doesn't load properly just undo the change. For any program:
Right-click on the icon/shortcut you use to launch the program
Select properties
In the 'target' box, add ' /prefetch:1¡¬ at the end of the line.
Click "Ok"
Ensure XP Is Using DMA Mode
XP enables DMA for Hard-Drives and CD-Roms by default on most ATA or ATAPI (IDE) devices. However, sometimes computers switch to PIO mode which is slower for data transfer - a typical reason is because of a virus. To ensure that your machine is using DMA:
Open 'Device Manager'
Double-click 'IDE ATA/ATAPI Controllers'
Right-click 'Primary Channel' and select 'Properties' and then 'Advanced Settings'
In the 'Current Transfer Mode' drop-down box, select 'DMA if Available' if the current setting is 'PIO Only'
Advanced
Speed Up Boot Times I
This tweak works by creating a batch file to clear the temp and history folders everytime you shutdown so that your PC doesn't waste time checking these folders the next time it boots. It's quite simple to implement:
Open Notepad and create a new file with the following entries:
RD /S /q "C:¢DDocuments and Settings"UserName without quotes"¢DLocal Settings¢DHistory"
RD /S /q "C:¢DDocuments and Settings¢DDefault User¢DLocal Settings¢DHistory"
RD /S /q "D:¢DTemp" <¡V"Deletes temp folder, type in the location of your temp folder"
Save the new as anything you like but it has to be a '.bat' file e.g. fastboot.bat or deltemp.bat
Click 'Start' then 'Run'
Type in 'gpedit.msc' and hit 'ok'
Click on 'Computer Configuration' then 'Windows Settings'
Double-click on 'Scripts' and then on 'Shutdown'
Click 'Add' and find the batch file that you created and then press 'Ok'
Speed Up Boot Times II
When your PC starts it usually looks for any bootable media in any floppy or cd-rom drives you have installed before it gets around to loading the Operating System from the HDD. This can waste valuable time. To fix this we need to make some changes to the Bios.
Note: Once this change has been made, you won't be able to boot from a floppy disc or a CD-rom. If for some strange reason you need to do this in the future, just go back into your bios, repeat the steps above and put your floppy or CD-rom back as the 'First Device'
To enter the bios you usually press 'F2¡¬ or 'delete' when your PC starts
Navigate to the 'Boot' menu
Select 'Boot Sequence'
Then either move your Hard drive to the top position or set it as the 'First Device'5. Press the 'Escape' key to leave the bios. Don't forget to save your settings before exiting
Speed Up Boot Times III
When your computer boots up it usually has to check with the network to see what IP addresses are free and then it grabs one of these. By configuring a manually assigned IP address your boot time will improve. To do this do the following:
Click on 'Start' and then "Connect To/Show All Connections'
Right-click your network adapter card and click 'Properties'
On the 'General' tab, select 'TCP/IP' in the list of services and click 'Properties'
In the TCP/IP properties, click 'Use the following address' and enter an IP address for your PC. If you are using a router this is usually 192.168.0.xx or 192.168.1.xx. If you are not sure what address you could check with your ISP or go to 'Start/run' and type 'cmd' and then 'ipconfig/all' . This will show your current IP settings which you will need to copy
Enter the correct details for 'Subnet mask', 'Default gateway' and 'DNS Server'. Again if you are not sure what figures to enter use 'ipconfig/all' as in stage 4
Disable Unnecessary Services
Because Windows XP has to be all things to all people it has many services running that take up system resources that you will never need.Below is a list of services that can be disabled on most machines:
To disable these services:
Alerter
Clipbook
Computer Browser
Distributed Link Tracking Client
Fast User Switching
Help and Support - (If you use Windows Help and Support leave this enabled)
Indexing Service
IPSEC Services
Messenger
Netmeeting Remote Desktop Sharing (disabled for extra security)
Portable Media Serial Number
Remote Desktop Help Session Manager (disabled for extra security)
Remote Procedure Call Locator
Remote Registry (disabled for extra security)
Remote Registry Service
Secondary Logon
Routing & Remote Access (disabled for extra security)
Server
SSDP Discovery Service - (Unplug n' Pray will disable this)
Telnet
TCP/IP NetBIOS Helper
Upload Manager
Universal Plug and Play Device Host
Windows Time
Wireless Zero Configuration (Do not disable if you use a wireless network)
Go to Start and then Run and type "services.msc"
Doubleclick on the service you want to change
Change the startup type to 'Disable"
Speedup Folder Access - Disable Last Access Update
If you have a lot of folders and subdirectories on your computer, when you access a directory XP wastes a lot of time updating the time stamp showing the last access time for that directory and for ALL sub directories. To stop XP doing this you need to edit the registry. If you are uncomfortable doing this then please do not attempt.
Go to Start and then Run and type "regedit"
Click through the file system until you get to "HKEY_LOCAL_ MACHINE¢DSystem¢DCurrentControlS et¢DControl¢DFileSystem"
Right-click in a blank area of the window on the right and select 'DWORD Value'
Create a new DWORD Value called 'NtfsDisableLastAcc essUpdate'
Then Right click on the new value and select 'Modify'
Change the Value Data to '1¡¬
Click 'OK'
Improve Boot Times
A great new feature in Microsoft Windows XP is the ability to do a boot defragment. This places all boot files next to each other on the disk to allow for faster booting. By default this option in enables but on some builds it is not so below is how to turn it on.
Go to Start Menu and Click Run
Type in "Regedit" then click ok
Find "HKEY_LOCAL_ MACHINE¢DSOFTWARE¢DMicrosoft¢DDfrg¢DBootOpt imizeFunction"
Select "Enable" from the list on the right
Right on it and select "Modify"
Change the value to "Y to enable"
Reboot
Improve Swapfile Performance
If you have more than 256MB of RAM this tweak will considerably improve your performance. It basically makes sure that your PC uses every last drop of memory (faster than swap file) before it starts using the swap file.
Go to Start then Run
Type "msconfig.exe" then ok
Click on the System.ini tab
Expand the 386enh tab by clicking on the plus sign
Click on new then in the blank box type"ConservativeSw apfileUsage= 1?
Click OK
Restart PC
Improve XP Shutdown Speed
This tweak reduces the time XP waits before automatically closing any running programs when you give it the command to shutdown.
Go to Start then select Run
Type 'Regedit' and click ok
Find 'HKEY_CURRENT_ USER¢DControl Panel¢DDesktop'Select 'WaitToKillAppTimeo ut'
Right click and select 'Modify'
Change the value to '1000¡¬
Click 'OK'
Now select 'HungAppTimeout'
Right click and select 'Modify'
Change the value to '1000¡¬
Click 'OK'
Now find 'HKEY_USERS¢D.DEFAULT¢DControl Panel¢DDesktop'
Select 'WaitToKillAppTimeo ut'
Right click and select 'Modify'
Change the value to '1000¡¬
Click 'OK'
Now find 'HKEY_LOCAL_ MACHINE¢DSystem¢DCurrentControlS et¢DControl'
Select 'WaitToKillServiceT imeout'
Right click and select 'Modify'
Change the value to '1000¡¬
Click 'OK'
Differences between the GSM and CDMA Wireless Networks
Differences between the GSM and CDMA Wireless Networks
GSM and CDMA have been the two leading commercial wireless technologies that are being used all over the world. This paper presents to the readers the key differences between the two technologies1. The various topics in which this paper presents the difference are:
Radio Spectrum Usage
Network architecture differences
Radio channel differences
Call Processing
Evolution to 3G
Network capacity differences
Deployment
Introduction
This section presents the basic wireless network architecture and lays the foundation for the readers to understand the later sections of this paper.
Though this paper concentrates on the differences between these networks, but the basic network architecture for both these networks is same.
The diagram below presents the general architecture of a wireless network.
1: This paper concentrates mostly on the differences in the BSS.
Figure 1: General Architecture of Wireless Networks
The Mobile Station
The Mobile Station (MS) is the user equipment in Wireless Networks.. Production of Mobile Stations is done by many different manufacturers, and there will almost always be a wide range of different Mobile Stations in a mobile network. Therefore the specifications specify the workings of the MS in great detail.
The Base Transceiver Station
The Base Transceiver Station (BTS) is the entity corresponding to one site communicating with the Mobile Stations. Usually, the BTS will have an antenna with several TRXs (radio transceivers) that each communicates on radio frequency. The link-level signaling on the radio-channels is interpreted in the BTS, whereas most of the higher-level signaling is forwarded to the BSC and MSC
The Base Station Controller
Each Base Station Controller (BSC) control the magnitude of several hundred BTSs. The BSC takes care of a number of different procedures regarding call setup, location update and handover for each MS. The handover control procedures will come especially into focus in this thesis. It is the BSC that decides when handover is necessary. This is accomplished by analyzing the measurement results that are sent from the MS during a call and ordering the MS to perform handover if this is necessary. The continuous analyzing of measurements from many MSs requires considerable computational power. This put strong constraints on the design of the BSC.
The Mobile Switching Center
The Mobile Switching Center is a normal ISDN-switch with extended functionality to handle mobile subscribers. The basic function of the MSC is to switch speech and data connections between BSCs, other MSCs, other Wireless networks and external non-mobile-networks . The MSC also handles a number of functions associated with mobile subscribers, among others registration, location updating and handover. There will normally exist only a few BSCs per MSC, due to the large number of BTSs connected to the BSC. The MSC and BSCs are connected via the highly standardized A-interface. However, due to the lack of standardization on Operation and Management protocols, network providers usually choose BSCs, MSCs and Location Registers from one manufacturer.
The Location Registers
With each MSC, there is associated a Visitors Location Register (VLR). The VLR can be associated with one or several MSCs. The VLR stores data about all customers who are roaming withing the location area of that MSC. This data is updated with the location update procedure initiated from the MS through the MSC, or directly from the subscriber Home Location Register (HLR). The HLR is the home register of the subscriber. Subscription information, allowed services, authentication information and localization of the subscriber are at all times stored in the HLR. This information may be obtained by the VLR/MSC when necessary. When the subscriber roams into the location area of another VLR/MSC, the HLR is updated. At mobile terminated calls, the HLR is interrogated to find which MSC the MS is registered with. Because the HLR is a centralized database that need to be accessed during every call setup and data transmission in the GSM network, this entity need to have a very large data transmission capacity suggests a scheme for distributing the data in the HLR in order to reduce the load.
The communication between MSC, VLR and HLR is done using the MAP (Mobile Application Part) of the Signalling System 7. The MAP is defined in and will be further discussed in
Historical View of GSM and CDMA
GSM
The first step towards GSM was the allocation of a common frequency band in 1978, twice 25 MHz, at around 900 MHz for mobile communication in Europe. In 1990, the GSM specifications for 900 MHz were frozen. In 1990 it was decided that GSM 1800
GSM radio interface GSM Phase 2+
8 channels per carrier Adaptive multirate coder
200 – KHz carrier bandwidth 14.4 Kbp data service
Slow frequency hopping General pocket radio service
Enhanced data rates using optimised modulation (EDGE)
Table 1 shows the time schedule of GSM.
Table 1 – GSM Development Time Schedule
1982
Groupe Special Mobile established within CEPT
1984
Several proposals for GSM multiple access : wideband TDMA, narrowband TDMA, DS- CDMA, hybrid CDMA/FDMA, narrowband FDMA
1986
Eight prototype systems tested in CNET laboratories in France
Permanent nucleus is set up
1987
Basic transmission principles selected : 8-slot TDMA, 200-kHz carrier spacing, frequency hopping
1987
MoU signed
1988
GSM becomes an ETSI technical committee
1990
GSM phase 1 specifications frozen (drafted 1987 – 1990)
GSM1800 standardisation begins
1991
GSM1800 specifications are frozen
1992
GSM900 commercial operation starts
1992
GSM phase 2+ development starts
1995
GSM submitted as a PCS technology candidate to the United States
1995
PCS1900 standard adopted in the United States
1996
Enhanced full rate (EFR) speech codec standard ready
1996
14.4-Kbps standard ready
GSM1900 commercial operation starts
1997
HSCSD standard ready
GSM cordless system (home base station) standardisation started
EDGE standardisation started
1998
GPRS standard ready
WCDMA selected as the third generation air interface
Classification of CDMA
based on the modulation method
CDMA : direct sequence (DS)
CDMA : frequency hopping (FH)
CDMA : time hopping (TH)
Frequency Direct sequence Frequency hopping
Time hopping Time
[1] In DS-CDMA, spectrum is spread by multiplying the information signal with a pseudo-noise sequence, resulting in a wideband signal.
[2] In FH-CDMA. In the frequency hopping spread spectrum, a pseudo-noise sequence defines the instantaneous transmission frequency. The bandwidth at each moment is small, but the total bandwidth over, for example, a symbol period is large. Frequency hopping can either be fast (several hops over one symbol) or slow (several symbols transmitted during one hop).
[3] In TH-CDMA, in the time hopping spread spectrum, a pseudo-noise sequence defines the transmission moment.
CDMA era, as shown in table 2 Table 2 – CDMA Era
Pioneer Era
1949
John Pierce : time hopping spread spectrum
1949
Claude Shannon and Robert Pierce : basic ideas of CDMA
1950
De Rosa-Rogoff : direct sequence spread spectrum
1956
Price and Green : antimultipath "RAKE" patent
1961
Magnuski : near-far problem
1970s
Several developments for military field and navigation systems
Narrowband CDMA Era
1978
Cooper and Nettleton : cellular application of spread spectrum
1980s
Investigation of narrowband CDMA techniques for cellular applications
1986
Formulation of optimum multiuser detection by Verdu
1993
IS-95 standard
Wideband CDMA Era
WCDMA1995 -
Europe : FRAMES FMA2
Japan : Core-A
USA : cdma2000
Korea : TTA I, TTA II
2000s
Commercialization of wideband CDMA systems
Table 3 shows the technical parameters of second generation systems. All these systems are frequency division duplex (FDD) systems. They transmit and receive in different frequency bands. Time division duplex (TDD). The actual data rate available in commercial systems is usually much smaller. In 1998 GSM supports 14.4 Kbps, IS-95 9.6 Kbps, IS-136 9.6Kbps and PDC 9.6 Kbps. Table 3 – Second Generation Digital Systems
GSM
IS-136
IS-95
PDC
Multiple access
TDMA
TDMA
CDMA
TDMA
Modulation
GMSKa
ð/4-DQPSKb
Coherent ð/4-
DQPSK
Coherent 8-PSK
QPSK/0-QPSKc
ð/4-DQPSK
Carrier spacing
200 kHz
30 kHz
1.25 MHz
25 kHz
Carrier bit rate
270.833 Kbps
48.6 Kbps (ð/4-PSK and ð/4-DQPSK) 72.9 Kbps (8-PSK)
1.2288 Mchip/sd
42 Kbps
Frame length
4.615 ms
40 ms
20 ms
20 ms
Slots per frame
8/16
6
1
3/6
Frequency band (uplink/
downlink)
(MHz)
880-915 / 935-960
1720-1785 /
1805-1880
1930-1990 /
1850-1910
824-849 / 869-894
1930-1990 /
1850-1910
824-849/869- 894
1930-1990 /
1850-1910
810-826 /
940-956
1429-1453/
1477-1501
Speech codec
RPE-LTPe 13 Kbps
Half rate 6.5 Kbps
Enhanced full rate
(EFR) 12.2 kbps
VSELPf 8 Kbps
IS-641-A: 7.4 Kbps
(ACELP)g
US1: 12.2 Kbps
(ACELP)
QCELP 8 Kbps
CELP 8 Kbps
CELP 13 Kbps
VCELP
6.7 Kbps
Maximum possible data rate
HSCSD:115.2 Kbps
GPRS : 115.2 –
182.4 Kbps
(depending on the coding)
IS-136+: 43.2 Kbps
IS95A:14.4 Kbps
IS95B:115.2 Kbps
28.8 Kbps
Frequency hopping
Yes
No
N/A
No
Handover
Hard
Hard
Soft
Hard
a Gaussian minimum shift keying
b Differential quadrature phase shift keying
c Offset QPSK
d A "chip" is used to denote a spread symbol in DS- CDMA systems
e Regular pulse excited long term prediction
f Vector sum excited linear predictive
g Algebraic code excited linear predictive
Comparison of Technologies
Frequency Division Multiple Access (FDMA):
The frequency spectrum is divided into number of narrow band channels. These channels are assigned to users. Therefore, users transmit in their assigned frequency range. This is the assigned dynamically. The frequency range can be reassigned once the call is completed. The frequency assigned serves as channel identifier.
Time Division to Multiple Access (TDMA):
As in FDMA, TDMA divides the spectrum into narrow band channels. However, in TDMA, the same channel is assigned to multiple users. The available time is divided into a number of time slots. These slots are assigned to users sharing the same channel. Thus, TDMA provides more spectral efficiency than FDMA. The capacity is increased N times, where N is the number of timeslots within in a channel. Thus, N users can be accommodated in a channel. The frequency assignment, along with the assigned time slot, serves as a channel identifier. This technology is used in GSM.
Code Division Multiple Access (CDMA):
In CDMA, all users share the wideband spectrum. Each user is spread with a pseudo-random binary sequence. The wide band frequency assignment (common to all users) along with a pseudo-random sequence serves as the channel identifier.
Network Architecture
This section presents the differences between the GSM and CDMA network architectures.
The diagram below shows the GSM network architecture:
The diagram below shows the IS-95 based CDMA network architecture:
Mobile Station:
GSM:
The mobile station (MS) consists of the mobile equipment (the terminal) and a smart card called the Subscriber Identity Module (SIM). The SIM provides personal mobility, so that the user can have access to subscribed services irrespective of a specific terminal. By inserting the SIM card into another GSM terminal, the user is able to receive calls at that terminal, make calls from that terminal, and receive other subscribed services.
The mobile equipment is uniquely identified by the International Mobile Equipment Identity (IMEI). The SIM card contains the International Mobile Subscriber Identity (IMSI) used to identify the subscriber to the system, a secret key for authentication, and other information. The IMEI and the IMSI are independent, thereby allowing personal mobility. The SIM card may be protected against unauthorized use by a password or personal identity number.
CDMA:
One of the biggest drawbacks of the CDMA mobile stations is the absence of the SIM card. As a result of this, a user's identity is fixed to a handset.
Electronic Serial Number (ESN) uniquely identifies the mobile equipment. ESN is a 32bit number assigned by the mobile station manufacturer.
An IMSI and ESN are linked in the operator database to uniquely identify a subscriber.
Cell Design
In CDMA, the same 1.233 MHz wideband channel may be reused in all the cells. Therefore, adjacent cells may use the same frequency; thus the frequency reuse factor is 1. This greatly simplifies the frequency planning.
On the other hand in GSM, the frequency assignments in one cell cannot be reused in adjacent cells. Hence, frequency assignments in each cell have to be carefully allocated to avoid interference from adjacent cells.
Base Station Sub-System (BSS):
An important component of the BSS, which is considered in the canonical GSM architecture as part of the BTS is TRAU, or the Transcoder/Rate Adapter Unit. The TRAU is the equipment in which the GSM specific speech encoder and decoding is carried out, as well as the rate adaptation in the case of data. Although the GMS specifications consider the TRAU as part of the BTS, it can be sited away from the BTS and in many cases it is actually between the BSC and MSC. Having the TRAU as close to MSC saves a lot on the 64kbps link between the BSC and the MSC.
Where as in CDMA , the TRAU is called the Vocoders and they are considered as part of the BSC.
Another key difference in the BSS is that the CDMA BSS gets the time synchronization between the various Network elements using the GPS, where as in GSM is it controlled by the MSC and BSS interface.
Radio Interface Differences
The radio interface in the wireless systems provides the link between the fixed infrastructure of different operators and the mobile station of various manufacturers.
The radio interface serves two main functions:
To transport user information, both speech and data – bi-directional.
To exchange signaling information between the mobile station and the network.
Uplink and Downlink differences:
The radio link directed from the mobile station to the network is called the uplink. This is also referred to as the reverse link in CDMA networks.
The radio link directed from network to the mobile station is called the downlink. This is referred to as the forward link in the CDMA networks.
Channels are used in pair for full duplex communications. Thus, GSM uses both uplink and downlink bands of a given spectrum.
In other words, a physical channel refers to a pair of frequencies used for a cellular radio talk path. One is used for the cell site to mobile transmission while the other is used for the mobile to the cell site transmission.
GMS signal requires channels spacing of 200kHz.
In CDMA two types of PN codes are used for differentiating the forward and the reverse links.
Short Codes
These PN codes are generated with a register length of 15. The length of the code is 215- (32,768) bits. Generated at the rate of 1.2288MHz, these codes repeat every 26.67 msec. Each base station generates a short code with a different offset that identifies the base station. Long Code
There is only one long code, it is defined in the standard, and it is used by all IS-95 and cdma 2000 systems. The long PN code is generated with a register length of 42. Generated at the rate of 1.2288MHz, this code repeats in approximately in 41 days. In the reverse direction, the long code is used for spreading (mobile to the base station) and to uniquely identify each channel. When the mobile needs to uniquely identify itself or a channel using the long code, it applies a long code mask to the long code, which results in a time shifted version of the long code. The receiver applies the same mask to recover the data.
Logical Channel differences
Both GSM and the CDMA networks have a lot of similarities in the way the logical channels are defined.
In brief both these networks have a
Channel, which is used by the mobile to acquire the system. This is called the Pilot channel in CDMA whereas it is called the FCCH in GSM.
A channel used by the mobile to synchronize to the network. This is called Synch channel in CDMA and in GSM it is called SCH.
Channel to transmit the system wide information and also page the mobile for the termination calls. This in GSM is achieved by two channels called BCCH and PCH, where as in CDMA a single Paging channel does this.
Traffic channels.
The diagrams below shows the logical channel structures of both CDMA and GSM networks.
The major difference between the GSM and the CDMA logical channels is how they are identified. In GSM each logical channel is pre-assigned to a particular time slot and in CDMA they are identified by a pre-assigned Walsh code.
And also in the traffic channel, during the call setup in a GMS the mobile is assigned to a time slot whereas in CDMA a particular Walsh code is assigned.
Call Processing
Both GSM and CDMA networks have similar call setup flows for the origination and the termination of calls and location management.
But the major difference is in the CDMA networks, which has both hard handoff and soft handoff whereas GSM networks have only hard handoffs.
Another major difference is how both these networks handle the Near-Far effect.
In GSM, during traffic a time slot is allocated for the mobile, when the mobile moves far away from the base station its round trip delay increases and the mobile tends to drift to another user time slot. To avoid this, time advance feature is used in GSM networks.
Similarly in CDMA networks, within a cell, mobiles are different radial distances from the base station. If all the mobiles transmit at equal power, the level received at the base station differs from one mobile to another. Mobiles that are nearer are received at significantly high power than the mobiles that are farther away. Because the transmission loss is higher for mobiles farther from the base station, mobiles near to the base station can cause more interference to the mobiles. Introducing power control during the call in the CDMA networks solves this problem.
Evolution to 3G
The diagram below shows the 3G evolution paths taken by each network. Here is a brief summary changes for the evolution of each network.
GSM to GPRS:
New additions: Packet core network nodes – SGSN and GGSN.
Modifications: BSC hardware and software
No Changes: Circuit core network (MSC, HLR, AuC), Air Interface (MS-BTS) and A-Interface (BSC-MSC)
The diagram below shows a 2.5 G GSM – GPRS network. GSM /GPRS to UMTS:
New additions: WCDMA Air Interface (UE-Node B), RAN Interfaces, Iub (Node B – RNC), IuR (RNC- RNC), CN Interface Iu (MSC- RNC & SGSN – RNC)
Modifications: MSC and SGSN for Iu Interface.
No Changes: Circuit core network (HLR, AuC), Packet Core Network (GGSN)
The diagram below shows the UMTS network. IS 95 to CDMA 2000:
New additions: Packet core network (PDSN, AAA, HA/FA), New Interface R-P (PDSN – BSS)
Modifications: Air Interface (MS-BSS), Network Interface (BSC- MSC)
No Changes: Circuit core network (HLR, AC)
The diagram below shows the CDMA2000 network.
Conclusion:
This paper tried to capture the technical differences between the world's two biggest wireless networks – GSM and CDMA. From the practical deployment point of view GMS captured Europe, Asia and Africa where as CDMA has been deployed in the Americas and some parts of Asia like Japan and Korea. Reference:
http://www.arcx. com/sites/ index.htm
GSM Wireless Networks – Nortel Networks Training Division
IS –95 Overview – Award Solutions
www.gmsworld. com
The GSM systems for Mobile Communications – Michel Mouly
Introduction to 3G Mobile Communications – Juha
DIFFERENCE BETWEEN CDMA VS TDMA
Last Updated: 15-Apr-2004
NOTE: During this discussion I will use the generic term "CDMA" to refer to the IS-95B standard. Technically speaking, CDMA is only a means to transmit bits of information, while IS-95B is a transmission protocol that employs CDMA. You may also hear the term "TDMA" used to refer generically to the IS-136 standard. Once again, TDMA is only a method of transmitting bits, while IS-136 is a protocol that happens to employ TDMA. I spend quite a bit of time reading the messages that flow through the various PCS newsgroups and forums on the Internet, and if one thing is abundantly clear, it is that people don't seem to know the true differences between CDMA and TDMA. And who could blame them? There is so much hype surrounding these two competing technologies that it is difficult for a regular PCS subscriber to know who is telling the truth. I personally am NOT an RF engineer, nor do I work for any of the cellular or PCS companies. It is however my hobby to keep up with the latest developments in mobile communication (as this web site amply demonstrates) . I would like to clear the air by interjecting my own spin on this debate. I hope that by the time you finish reading this editorial you will have a better understanding of the true strengths and weaknesses of both technologies. The BasicsLet's begin by learning what these two acronyms stand for. TDMA stands for "Time Division Multiple Access", while CDMA stands for "Code Division Multiple Access". Three of the four words in each acronym are identical, since each technology essentially achieves the same goal, but by using different methods. Each strives to better utilize the radio spectrum by allowing multiple users to share the same physical channel. You heard that right. More than one person can carry on a conversation on the same frequency without causing interference. This is the magic of digital technology. Where the two competing technologies differ is in the manner in which users share the common resource. TDMA does it by chopping up the channel into sequential time slices. Each user of the channel takes turns transmitting and receiving in a round-robin fashion. In reality, only one person is actually using the channel at any given moment, but he or she only uses it for short bursts. He then gives up the channel momentarily to allow the other users to have their turn. This is very similar to how a computer with just one processor can seem to run multiple applications simultaneously. CDMA on the hand really does let everyone transmit at the same time. Conventional wisdom would lead you to believe that this is simply not possible. Using conventional modulation techniques, it most certainly is impossible. What makes CDMA work is a special type of digital modulation called "Spread Spectrum". This form of modulation takes the user's stream of bits and splatters them across a very wide channel in a pseudo-random fashion. The "pseudo" part is very important here, since the receiver must be able to undo the randomization in order to collect the bits together in a coherent order. If you are still having trouble understanding the differences though, perhaps this analogy will help you. This my own version of an excellent analogy provided by Qualcomm:Imagine a room full of people, all trying to carry on one-on-one conversations. In TDMA each couple takes turns talking. They keep their turns short by saying only one sentence at a time. As there is never more than one person speaking in the room at any given moment, no one has to worry about being heard over the background din. In CDMA each couple talks at the same time, but they all use a different language. Because none of the listeners understand any language other than that of the individual to whom they are listening, the background din doesn't cause any real problem. Voice EncodingAt this point many people confuse two distinctly different issues involved in the transmission of digital audio. The first is the WAY in which the stream of bits is delivered from one end to the other. This part of the "air interface" is what makes one technology different from another. The second is the compression algorithm used to squeeze the audio into as small a stream of bits as possible. This latter component is known at the "Voice Coder", or Vocoder for short. Another term commonly used is CODEC, which is a similar word to modem. It combines the terms "COder" and "DECoder". Although each technology has chosen their own unique CODECs, there is no rule saying that one transmission method needs to use a specific CODEC. People often lump a technology's transmission method with its CODEC as though they were single entities. We will discuss CODECs in greater detail later on in this article. Voice encoding schemes differ slightly in their approach to the problem. Because of this, certain types of human voice work better with some CODECs than they do with others. The point to remember is that all PCS CODECs are compromises of some sort. Since human voices have such a fantastic range of pitch and tonal depth, one cannot expect any single compromise to handle each one equally well. This inability to cope with all types of voice at the same level does lead some people to choose one technology over another. All of the PCS technologies try to minimize battery consumption during calls by keeping the transmission of unnecessary data to a minimum. The phone decides whether or not you are presently speaking, or if the sound it hears is just background noise. If the phone determines that there is no intelligent data to transmit it blanks the audio and it reduces the transmitter duty cycle (in the case of TDMA) or the number of transmitted bits (in the case of CDMA). When the audio is blanked your caller would suddenly find themselves listening to "dead air", and this may cause them to think the call has dropped. To avoid this psychological problem many service providers insert what is known as "Comfort Noise" during the blanked periods. Comfort Noise is synthesized white noise that tries to mimic the volume and structure of the real background noise. This fake background noise assures the caller that the connection is alive and well.
However, in newer CODECs such as EVRC (used exclusively on CDMA systems) the background noise is generally suppressed even while the user is talking. This piece of magic makes it sound as though the cell phone user is not in a noisy environment at all. Under these conditions, Comfort Noise is neither necessary, nor desirable. You can read my article on EVRC by clicking here.CDMANow that we have a rudimentary understanding of the two technologies, let's try and examine what advantages they provide. We'll begin with CDMA, since this newer technology has created the greatest "buzz" in the mobile communications industry. One of the terms you'll hear in conjunction with CDMA is "Soft Handoff". A handoff occurs in any cellular system when your call switches from one cell site to another as you travel. In all other technologies this handoff occurs when the network informs your phone of the new channel to which it must switch. The phone then stops receiving and transmitting on the old channel, and it commences transmitting and receiving on the new channel. It goes without saying that this is known as a "Hard Handoff". In CDMA however, every site are on the SAME frequency. In order to begin listening to a new site the phone only needs to change the pseudo-random sequence it uses to decode the desired data from the jumble of bits sent for everyone else. While a call is in progress the network chooses two or more alternate sites that it feels are handoff candidates. It simultaneously broadcasts a copy of your call on each of these sites. Your phone can then pick and choose between the different sources for your call, and move between them whenever it feels like it. It can even combine the data received from two or more different sites to ease the transition from one to the other. This arrangement therefore puts the phone in almost complete control of the handoff process. Such an arrangement should ensure that there is always a new site primed and ready to take over the call at a moment's notice. In theory, this should put an end to dropped calls and audio interruptions during the handoff process. In practice it works quite well, but dropped calls are still a fact of life in a mobile environment. However, CDMA rarely drops a call due to a failed handoff. A big problem facing CDMA systems is channel pollution. This occurs when signals from too many base stations are present at the subscriber's phone, but none are dominant. When this situation occurs the audio quality degrades rapidly, even when the signal seem otherwise very strong. Pollution occurs frequently in densely populated urban environments where service providers must build many sites in close proximity. Channel pollution can also result from massive multipath problems caused by many tall buildings. Taming pollution is a tuning and system design issue. It is up to the service provider to reduce this phenomenon as much as possible. In defense of CDMA however, I should point out that the new EVRC CODEC is far more robust than either of the earlier CODECs. Because of its increased robustness it provides much more consistent audio in the face of high frame error rates. EVRC is an 8 kilobit CODEC that provides audio quality that is almost as good to the older 13 kilobit CODEC. Since CDMA consumes only as much of the "ether" as a user talks, switching everyone to an 8 kilobit CODEC was an inevitable move.
Don't confuse EVRC with the old (and unlamented) 8 kilobit CODEC implemented in the early days of CDMA deployment. That CODEC was simply awful, and very few good things could be said about it. EVRC is a far more advanced compression algorithm that cleans up many of the stability problems inherent in the two older CODECs. The sound reproduction is slightly muddier than the 13 kilobit CODEC, but the improvement in stability makes up for this.Supporters often cite capacity as one CDMA's biggest assets. Virtually no one disagrees that CDMA has a very high "spectral efficiency". It can accommodate more users per MHz of bandwidth than any other technology. What experts do not agree upon is by how much. Unlike other technologies, in which the capacity is fixed and easily computed, CDMA has what is known as "Soft Capacity". You can always add just one more caller to a CDMA channel, but once you get past a certain point you begin to pollute the channel such that it becomes difficult to retrieve an error-free data stream for any of the participants.The ultimate capacity of a system is therefore dependent upon where you draw the line. How much degradation is a carrier willing to subject their subscribers to before they admit that they have run out of useable capacity? Even if someone does set a standard error rate at which these calculations are made, it does not mean that you personally will find the service particularly acceptable at that error rate.
TDMALet's move away from CDMA now and have a look at TDMA. Before we can go any further though, I should note that there are actually three different flavors of TDMA in the PCS market. Each of these technologies implements TDMA in a slightly different way. The most complex implementation is, without a doubt, GSM. It overlays the basic TDMA principles with many innovations that reduce the potential problems inherent in the system. To reduce the effects of co-channel interference, multipath, and fading, the GSM network can use something known as Frequency Hopping. This means that your call literally jumps from one channel to another at fairly short intervals. By doing this the likelihood of a given RF problem is randomized, and the effects are far less noticeable to the end user. Frequency Hopping is always available, but not mandated. This means that your GSM provider may or may not use it. iDEN is a proprietary Motorola technology that no other company seems to participate in. Only Motorola makes iDEN phones, and only Motorola makes iDEN infrastructure equipment. Perhaps the company guards its technology on purpose. iDEN was initially deployed as an alternative to standard packet radio systems commonly used by public safety and business users. However, it also provided phone interconnect services that are extinguishable from phone services offered by the other PCS systems, as well as packet data services for web browsing and hooking up your laptop to the Internet.
Finally there is the old IS-136 technology, but this is now an officially dead technology. All of the North American providers who used it (Rogers, Cingular, and AT&T) are abandoning it in favor of GSM. The same is happening in other parts of the world where IS-136 was used. I therefore will not spend much time talking about this variation of TDMA. Each of these TDMA technologies uses a different CODEC. GSM sports a CODEC called EFR (short for Enhanced Full Rate). This CODEC is arguable the best sounding one available in the PCS world. IS-136 used to sound horrible, but in the fall of 1997 they replaced their old CODEC with a new one. This new CODEC sounds much better than the old, but it doesn't quite match the GSM and CDMA entries. TDMA systems still rely on the switch to determine when to perform a handoff. Unlike the old analog system however, the switch does not do this in a vacuum. The TDMA handset constantly monitors the signals coming from other sites, and it reports this information to the switch without the caller being aware of it. The switch then uses this information to make better handoff choices at more appropriate times.
Perhaps the most annoying aspect of TDMA system to some people is the obviousness of handoffs. Some people don't tend to hear them, and I can only envy those individuals. Those of us who are sensitive to the slight interruptions caused by handoffs will probably find GSM the most frustrating. It's handoffs are by far the most messy. When handoffs occur infrequently (such as when we are stationary or in areas with few sites), they really don't present a problem at all. However, when they occur very frequently (while travelling in an area with a huge number of sites) they can become annoying. Spectral EfficiencyChannel capacity in a TDMA system is fixed and indisputable. Each channel carries a finite number of "slots", and you can never accommodate a new caller once each of those slots is filled. Spectral efficiency varies from one technology to another, but computing a precise number is still a contentious issue. For example, GSM provides 8 slots in a channel 200 kHz wide, while iDEN provides 3 slots in a channel only 25 kHz wide. GSM therefore consumes 25 kHz per user, while IS-136 consumes only 8.333 kHz per user. When Direct Connect is used on iDEN, 6 users can be stuffed into a single channel, thus only 4.166 kHz is consumer per user. There is also a new 6:1 interconnect CODEC coming for iDEN which will allow 6 phone users per channel. One would be sorely tempted to proclaim that iDEN has 3 to 6 times the capacity of GSM. In a one-cell system this is certainly true, but once we start deploying multiple cells and channel reuse the situation becomes more complex. Due to GSM's better error management and frequency hopping the interference of a co-channel site is greatly reduced. This allows frequencies to be reused more frequently without a degradation in the overall quality of the service. Capacity is measured in "calls per cell per MHz". An GSM system using N=4 reuse (this means you have 4 different sets of frequencies to spread out around town) the figure is 5.0 We get an efficiency value of 6.6 fo
GSM and CDMA have been the two leading commercial wireless technologies that are being used all over the world. This paper presents to the readers the key differences between the two technologies1. The various topics in which this paper presents the difference are:
Radio Spectrum Usage
Network architecture differences
Radio channel differences
Call Processing
Evolution to 3G
Network capacity differences
Deployment
Introduction
This section presents the basic wireless network architecture and lays the foundation for the readers to understand the later sections of this paper.
Though this paper concentrates on the differences between these networks, but the basic network architecture for both these networks is same.
The diagram below presents the general architecture of a wireless network.
1: This paper concentrates mostly on the differences in the BSS.
Figure 1: General Architecture of Wireless Networks
The Mobile Station
The Mobile Station (MS) is the user equipment in Wireless Networks.. Production of Mobile Stations is done by many different manufacturers, and there will almost always be a wide range of different Mobile Stations in a mobile network. Therefore the specifications specify the workings of the MS in great detail.
The Base Transceiver Station
The Base Transceiver Station (BTS) is the entity corresponding to one site communicating with the Mobile Stations. Usually, the BTS will have an antenna with several TRXs (radio transceivers) that each communicates on radio frequency. The link-level signaling on the radio-channels is interpreted in the BTS, whereas most of the higher-level signaling is forwarded to the BSC and MSC
The Base Station Controller
Each Base Station Controller (BSC) control the magnitude of several hundred BTSs. The BSC takes care of a number of different procedures regarding call setup, location update and handover for each MS. The handover control procedures will come especially into focus in this thesis. It is the BSC that decides when handover is necessary. This is accomplished by analyzing the measurement results that are sent from the MS during a call and ordering the MS to perform handover if this is necessary. The continuous analyzing of measurements from many MSs requires considerable computational power. This put strong constraints on the design of the BSC.
The Mobile Switching Center
The Mobile Switching Center is a normal ISDN-switch with extended functionality to handle mobile subscribers. The basic function of the MSC is to switch speech and data connections between BSCs, other MSCs, other Wireless networks and external non-mobile-networks . The MSC also handles a number of functions associated with mobile subscribers, among others registration, location updating and handover. There will normally exist only a few BSCs per MSC, due to the large number of BTSs connected to the BSC. The MSC and BSCs are connected via the highly standardized A-interface. However, due to the lack of standardization on Operation and Management protocols, network providers usually choose BSCs, MSCs and Location Registers from one manufacturer.
The Location Registers
With each MSC, there is associated a Visitors Location Register (VLR). The VLR can be associated with one or several MSCs. The VLR stores data about all customers who are roaming withing the location area of that MSC. This data is updated with the location update procedure initiated from the MS through the MSC, or directly from the subscriber Home Location Register (HLR). The HLR is the home register of the subscriber. Subscription information, allowed services, authentication information and localization of the subscriber are at all times stored in the HLR. This information may be obtained by the VLR/MSC when necessary. When the subscriber roams into the location area of another VLR/MSC, the HLR is updated. At mobile terminated calls, the HLR is interrogated to find which MSC the MS is registered with. Because the HLR is a centralized database that need to be accessed during every call setup and data transmission in the GSM network, this entity need to have a very large data transmission capacity suggests a scheme for distributing the data in the HLR in order to reduce the load.
The communication between MSC, VLR and HLR is done using the MAP (Mobile Application Part) of the Signalling System 7. The MAP is defined in and will be further discussed in
Historical View of GSM and CDMA
GSM
The first step towards GSM was the allocation of a common frequency band in 1978, twice 25 MHz, at around 900 MHz for mobile communication in Europe. In 1990, the GSM specifications for 900 MHz were frozen. In 1990 it was decided that GSM 1800
GSM radio interface GSM Phase 2+
8 channels per carrier Adaptive multirate coder
200 – KHz carrier bandwidth 14.4 Kbp data service
Slow frequency hopping General pocket radio service
Enhanced data rates using optimised modulation (EDGE)
Table 1 shows the time schedule of GSM.
Table 1 – GSM Development Time Schedule
1982
Groupe Special Mobile established within CEPT
1984
Several proposals for GSM multiple access : wideband TDMA, narrowband TDMA, DS- CDMA, hybrid CDMA/FDMA, narrowband FDMA
1986
Eight prototype systems tested in CNET laboratories in France
Permanent nucleus is set up
1987
Basic transmission principles selected : 8-slot TDMA, 200-kHz carrier spacing, frequency hopping
1987
MoU signed
1988
GSM becomes an ETSI technical committee
1990
GSM phase 1 specifications frozen (drafted 1987 – 1990)
GSM1800 standardisation begins
1991
GSM1800 specifications are frozen
1992
GSM900 commercial operation starts
1992
GSM phase 2+ development starts
1995
GSM submitted as a PCS technology candidate to the United States
1995
PCS1900 standard adopted in the United States
1996
Enhanced full rate (EFR) speech codec standard ready
1996
14.4-Kbps standard ready
GSM1900 commercial operation starts
1997
HSCSD standard ready
GSM cordless system (home base station) standardisation started
EDGE standardisation started
1998
GPRS standard ready
WCDMA selected as the third generation air interface
Classification of CDMA
based on the modulation method
CDMA : direct sequence (DS)
CDMA : frequency hopping (FH)
CDMA : time hopping (TH)
Frequency Direct sequence Frequency hopping
Time hopping Time
[1] In DS-CDMA, spectrum is spread by multiplying the information signal with a pseudo-noise sequence, resulting in a wideband signal.
[2] In FH-CDMA. In the frequency hopping spread spectrum, a pseudo-noise sequence defines the instantaneous transmission frequency. The bandwidth at each moment is small, but the total bandwidth over, for example, a symbol period is large. Frequency hopping can either be fast (several hops over one symbol) or slow (several symbols transmitted during one hop).
[3] In TH-CDMA, in the time hopping spread spectrum, a pseudo-noise sequence defines the transmission moment.
CDMA era, as shown in table 2 Table 2 – CDMA Era
Pioneer Era
1949
John Pierce : time hopping spread spectrum
1949
Claude Shannon and Robert Pierce : basic ideas of CDMA
1950
De Rosa-Rogoff : direct sequence spread spectrum
1956
Price and Green : antimultipath "RAKE" patent
1961
Magnuski : near-far problem
1970s
Several developments for military field and navigation systems
Narrowband CDMA Era
1978
Cooper and Nettleton : cellular application of spread spectrum
1980s
Investigation of narrowband CDMA techniques for cellular applications
1986
Formulation of optimum multiuser detection by Verdu
1993
IS-95 standard
Wideband CDMA Era
WCDMA1995 -
Europe : FRAMES FMA2
Japan : Core-A
USA : cdma2000
Korea : TTA I, TTA II
2000s
Commercialization of wideband CDMA systems
Table 3 shows the technical parameters of second generation systems. All these systems are frequency division duplex (FDD) systems. They transmit and receive in different frequency bands. Time division duplex (TDD). The actual data rate available in commercial systems is usually much smaller. In 1998 GSM supports 14.4 Kbps, IS-95 9.6 Kbps, IS-136 9.6Kbps and PDC 9.6 Kbps. Table 3 – Second Generation Digital Systems
GSM
IS-136
IS-95
PDC
Multiple access
TDMA
TDMA
CDMA
TDMA
Modulation
GMSKa
ð/4-DQPSKb
Coherent ð/4-
DQPSK
Coherent 8-PSK
QPSK/0-QPSKc
ð/4-DQPSK
Carrier spacing
200 kHz
30 kHz
1.25 MHz
25 kHz
Carrier bit rate
270.833 Kbps
48.6 Kbps (ð/4-PSK and ð/4-DQPSK) 72.9 Kbps (8-PSK)
1.2288 Mchip/sd
42 Kbps
Frame length
4.615 ms
40 ms
20 ms
20 ms
Slots per frame
8/16
6
1
3/6
Frequency band (uplink/
downlink)
(MHz)
880-915 / 935-960
1720-1785 /
1805-1880
1930-1990 /
1850-1910
824-849 / 869-894
1930-1990 /
1850-1910
824-849/869- 894
1930-1990 /
1850-1910
810-826 /
940-956
1429-1453/
1477-1501
Speech codec
RPE-LTPe 13 Kbps
Half rate 6.5 Kbps
Enhanced full rate
(EFR) 12.2 kbps
VSELPf 8 Kbps
IS-641-A: 7.4 Kbps
(ACELP)g
US1: 12.2 Kbps
(ACELP)
QCELP 8 Kbps
CELP 8 Kbps
CELP 13 Kbps
VCELP
6.7 Kbps
Maximum possible data rate
HSCSD:115.2 Kbps
GPRS : 115.2 –
182.4 Kbps
(depending on the coding)
IS-136+: 43.2 Kbps
IS95A:14.4 Kbps
IS95B:115.2 Kbps
28.8 Kbps
Frequency hopping
Yes
No
N/A
No
Handover
Hard
Hard
Soft
Hard
a Gaussian minimum shift keying
b Differential quadrature phase shift keying
c Offset QPSK
d A "chip" is used to denote a spread symbol in DS- CDMA systems
e Regular pulse excited long term prediction
f Vector sum excited linear predictive
g Algebraic code excited linear predictive
Comparison of Technologies
Frequency Division Multiple Access (FDMA):
The frequency spectrum is divided into number of narrow band channels. These channels are assigned to users. Therefore, users transmit in their assigned frequency range. This is the assigned dynamically. The frequency range can be reassigned once the call is completed. The frequency assigned serves as channel identifier.
Time Division to Multiple Access (TDMA):
As in FDMA, TDMA divides the spectrum into narrow band channels. However, in TDMA, the same channel is assigned to multiple users. The available time is divided into a number of time slots. These slots are assigned to users sharing the same channel. Thus, TDMA provides more spectral efficiency than FDMA. The capacity is increased N times, where N is the number of timeslots within in a channel. Thus, N users can be accommodated in a channel. The frequency assignment, along with the assigned time slot, serves as a channel identifier. This technology is used in GSM.
Code Division Multiple Access (CDMA):
In CDMA, all users share the wideband spectrum. Each user is spread with a pseudo-random binary sequence. The wide band frequency assignment (common to all users) along with a pseudo-random sequence serves as the channel identifier.
Network Architecture
This section presents the differences between the GSM and CDMA network architectures.
The diagram below shows the GSM network architecture:
The diagram below shows the IS-95 based CDMA network architecture:
Mobile Station:
GSM:
The mobile station (MS) consists of the mobile equipment (the terminal) and a smart card called the Subscriber Identity Module (SIM). The SIM provides personal mobility, so that the user can have access to subscribed services irrespective of a specific terminal. By inserting the SIM card into another GSM terminal, the user is able to receive calls at that terminal, make calls from that terminal, and receive other subscribed services.
The mobile equipment is uniquely identified by the International Mobile Equipment Identity (IMEI). The SIM card contains the International Mobile Subscriber Identity (IMSI) used to identify the subscriber to the system, a secret key for authentication, and other information. The IMEI and the IMSI are independent, thereby allowing personal mobility. The SIM card may be protected against unauthorized use by a password or personal identity number.
CDMA:
One of the biggest drawbacks of the CDMA mobile stations is the absence of the SIM card. As a result of this, a user's identity is fixed to a handset.
Electronic Serial Number (ESN) uniquely identifies the mobile equipment. ESN is a 32bit number assigned by the mobile station manufacturer.
An IMSI and ESN are linked in the operator database to uniquely identify a subscriber.
Cell Design
In CDMA, the same 1.233 MHz wideband channel may be reused in all the cells. Therefore, adjacent cells may use the same frequency; thus the frequency reuse factor is 1. This greatly simplifies the frequency planning.
On the other hand in GSM, the frequency assignments in one cell cannot be reused in adjacent cells. Hence, frequency assignments in each cell have to be carefully allocated to avoid interference from adjacent cells.
Base Station Sub-System (BSS):
An important component of the BSS, which is considered in the canonical GSM architecture as part of the BTS is TRAU, or the Transcoder/Rate Adapter Unit. The TRAU is the equipment in which the GSM specific speech encoder and decoding is carried out, as well as the rate adaptation in the case of data. Although the GMS specifications consider the TRAU as part of the BTS, it can be sited away from the BTS and in many cases it is actually between the BSC and MSC. Having the TRAU as close to MSC saves a lot on the 64kbps link between the BSC and the MSC.
Where as in CDMA , the TRAU is called the Vocoders and they are considered as part of the BSC.
Another key difference in the BSS is that the CDMA BSS gets the time synchronization between the various Network elements using the GPS, where as in GSM is it controlled by the MSC and BSS interface.
Radio Interface Differences
The radio interface in the wireless systems provides the link between the fixed infrastructure of different operators and the mobile station of various manufacturers.
The radio interface serves two main functions:
To transport user information, both speech and data – bi-directional.
To exchange signaling information between the mobile station and the network.
Uplink and Downlink differences:
The radio link directed from the mobile station to the network is called the uplink. This is also referred to as the reverse link in CDMA networks.
The radio link directed from network to the mobile station is called the downlink. This is referred to as the forward link in the CDMA networks.
Channels are used in pair for full duplex communications. Thus, GSM uses both uplink and downlink bands of a given spectrum.
In other words, a physical channel refers to a pair of frequencies used for a cellular radio talk path. One is used for the cell site to mobile transmission while the other is used for the mobile to the cell site transmission.
GMS signal requires channels spacing of 200kHz.
In CDMA two types of PN codes are used for differentiating the forward and the reverse links.
Short Codes
These PN codes are generated with a register length of 15. The length of the code is 215- (32,768) bits. Generated at the rate of 1.2288MHz, these codes repeat every 26.67 msec. Each base station generates a short code with a different offset that identifies the base station. Long Code
There is only one long code, it is defined in the standard, and it is used by all IS-95 and cdma 2000 systems. The long PN code is generated with a register length of 42. Generated at the rate of 1.2288MHz, this code repeats in approximately in 41 days. In the reverse direction, the long code is used for spreading (mobile to the base station) and to uniquely identify each channel. When the mobile needs to uniquely identify itself or a channel using the long code, it applies a long code mask to the long code, which results in a time shifted version of the long code. The receiver applies the same mask to recover the data.
Logical Channel differences
Both GSM and the CDMA networks have a lot of similarities in the way the logical channels are defined.
In brief both these networks have a
Channel, which is used by the mobile to acquire the system. This is called the Pilot channel in CDMA whereas it is called the FCCH in GSM.
A channel used by the mobile to synchronize to the network. This is called Synch channel in CDMA and in GSM it is called SCH.
Channel to transmit the system wide information and also page the mobile for the termination calls. This in GSM is achieved by two channels called BCCH and PCH, where as in CDMA a single Paging channel does this.
Traffic channels.
The diagrams below shows the logical channel structures of both CDMA and GSM networks.
The major difference between the GSM and the CDMA logical channels is how they are identified. In GSM each logical channel is pre-assigned to a particular time slot and in CDMA they are identified by a pre-assigned Walsh code.
And also in the traffic channel, during the call setup in a GMS the mobile is assigned to a time slot whereas in CDMA a particular Walsh code is assigned.
Call Processing
Both GSM and CDMA networks have similar call setup flows for the origination and the termination of calls and location management.
But the major difference is in the CDMA networks, which has both hard handoff and soft handoff whereas GSM networks have only hard handoffs.
Another major difference is how both these networks handle the Near-Far effect.
In GSM, during traffic a time slot is allocated for the mobile, when the mobile moves far away from the base station its round trip delay increases and the mobile tends to drift to another user time slot. To avoid this, time advance feature is used in GSM networks.
Similarly in CDMA networks, within a cell, mobiles are different radial distances from the base station. If all the mobiles transmit at equal power, the level received at the base station differs from one mobile to another. Mobiles that are nearer are received at significantly high power than the mobiles that are farther away. Because the transmission loss is higher for mobiles farther from the base station, mobiles near to the base station can cause more interference to the mobiles. Introducing power control during the call in the CDMA networks solves this problem.
Evolution to 3G
The diagram below shows the 3G evolution paths taken by each network. Here is a brief summary changes for the evolution of each network.
GSM to GPRS:
New additions: Packet core network nodes – SGSN and GGSN.
Modifications: BSC hardware and software
No Changes: Circuit core network (MSC, HLR, AuC), Air Interface (MS-BTS) and A-Interface (BSC-MSC)
The diagram below shows a 2.5 G GSM – GPRS network. GSM /GPRS to UMTS:
New additions: WCDMA Air Interface (UE-Node B), RAN Interfaces, Iub (Node B – RNC), IuR (RNC- RNC), CN Interface Iu (MSC- RNC & SGSN – RNC)
Modifications: MSC and SGSN for Iu Interface.
No Changes: Circuit core network (HLR, AuC), Packet Core Network (GGSN)
The diagram below shows the UMTS network. IS 95 to CDMA 2000:
New additions: Packet core network (PDSN, AAA, HA/FA), New Interface R-P (PDSN – BSS)
Modifications: Air Interface (MS-BSS), Network Interface (BSC- MSC)
No Changes: Circuit core network (HLR, AC)
The diagram below shows the CDMA2000 network.
Conclusion:
This paper tried to capture the technical differences between the world's two biggest wireless networks – GSM and CDMA. From the practical deployment point of view GMS captured Europe, Asia and Africa where as CDMA has been deployed in the Americas and some parts of Asia like Japan and Korea. Reference:
http://www.arcx. com/sites/ index.htm
GSM Wireless Networks – Nortel Networks Training Division
IS –95 Overview – Award Solutions
www.gmsworld. com
The GSM systems for Mobile Communications – Michel Mouly
Introduction to 3G Mobile Communications – Juha
DIFFERENCE BETWEEN CDMA VS TDMA
Last Updated: 15-Apr-2004
NOTE: During this discussion I will use the generic term "CDMA" to refer to the IS-95B standard. Technically speaking, CDMA is only a means to transmit bits of information, while IS-95B is a transmission protocol that employs CDMA. You may also hear the term "TDMA" used to refer generically to the IS-136 standard. Once again, TDMA is only a method of transmitting bits, while IS-136 is a protocol that happens to employ TDMA. I spend quite a bit of time reading the messages that flow through the various PCS newsgroups and forums on the Internet, and if one thing is abundantly clear, it is that people don't seem to know the true differences between CDMA and TDMA. And who could blame them? There is so much hype surrounding these two competing technologies that it is difficult for a regular PCS subscriber to know who is telling the truth. I personally am NOT an RF engineer, nor do I work for any of the cellular or PCS companies. It is however my hobby to keep up with the latest developments in mobile communication (as this web site amply demonstrates) . I would like to clear the air by interjecting my own spin on this debate. I hope that by the time you finish reading this editorial you will have a better understanding of the true strengths and weaknesses of both technologies. The BasicsLet's begin by learning what these two acronyms stand for. TDMA stands for "Time Division Multiple Access", while CDMA stands for "Code Division Multiple Access". Three of the four words in each acronym are identical, since each technology essentially achieves the same goal, but by using different methods. Each strives to better utilize the radio spectrum by allowing multiple users to share the same physical channel. You heard that right. More than one person can carry on a conversation on the same frequency without causing interference. This is the magic of digital technology. Where the two competing technologies differ is in the manner in which users share the common resource. TDMA does it by chopping up the channel into sequential time slices. Each user of the channel takes turns transmitting and receiving in a round-robin fashion. In reality, only one person is actually using the channel at any given moment, but he or she only uses it for short bursts. He then gives up the channel momentarily to allow the other users to have their turn. This is very similar to how a computer with just one processor can seem to run multiple applications simultaneously. CDMA on the hand really does let everyone transmit at the same time. Conventional wisdom would lead you to believe that this is simply not possible. Using conventional modulation techniques, it most certainly is impossible. What makes CDMA work is a special type of digital modulation called "Spread Spectrum". This form of modulation takes the user's stream of bits and splatters them across a very wide channel in a pseudo-random fashion. The "pseudo" part is very important here, since the receiver must be able to undo the randomization in order to collect the bits together in a coherent order. If you are still having trouble understanding the differences though, perhaps this analogy will help you. This my own version of an excellent analogy provided by Qualcomm:Imagine a room full of people, all trying to carry on one-on-one conversations. In TDMA each couple takes turns talking. They keep their turns short by saying only one sentence at a time. As there is never more than one person speaking in the room at any given moment, no one has to worry about being heard over the background din. In CDMA each couple talks at the same time, but they all use a different language. Because none of the listeners understand any language other than that of the individual to whom they are listening, the background din doesn't cause any real problem. Voice EncodingAt this point many people confuse two distinctly different issues involved in the transmission of digital audio. The first is the WAY in which the stream of bits is delivered from one end to the other. This part of the "air interface" is what makes one technology different from another. The second is the compression algorithm used to squeeze the audio into as small a stream of bits as possible. This latter component is known at the "Voice Coder", or Vocoder for short. Another term commonly used is CODEC, which is a similar word to modem. It combines the terms "COder" and "DECoder". Although each technology has chosen their own unique CODECs, there is no rule saying that one transmission method needs to use a specific CODEC. People often lump a technology's transmission method with its CODEC as though they were single entities. We will discuss CODECs in greater detail later on in this article. Voice encoding schemes differ slightly in their approach to the problem. Because of this, certain types of human voice work better with some CODECs than they do with others. The point to remember is that all PCS CODECs are compromises of some sort. Since human voices have such a fantastic range of pitch and tonal depth, one cannot expect any single compromise to handle each one equally well. This inability to cope with all types of voice at the same level does lead some people to choose one technology over another. All of the PCS technologies try to minimize battery consumption during calls by keeping the transmission of unnecessary data to a minimum. The phone decides whether or not you are presently speaking, or if the sound it hears is just background noise. If the phone determines that there is no intelligent data to transmit it blanks the audio and it reduces the transmitter duty cycle (in the case of TDMA) or the number of transmitted bits (in the case of CDMA). When the audio is blanked your caller would suddenly find themselves listening to "dead air", and this may cause them to think the call has dropped. To avoid this psychological problem many service providers insert what is known as "Comfort Noise" during the blanked periods. Comfort Noise is synthesized white noise that tries to mimic the volume and structure of the real background noise. This fake background noise assures the caller that the connection is alive and well.
However, in newer CODECs such as EVRC (used exclusively on CDMA systems) the background noise is generally suppressed even while the user is talking. This piece of magic makes it sound as though the cell phone user is not in a noisy environment at all. Under these conditions, Comfort Noise is neither necessary, nor desirable. You can read my article on EVRC by clicking here.CDMANow that we have a rudimentary understanding of the two technologies, let's try and examine what advantages they provide. We'll begin with CDMA, since this newer technology has created the greatest "buzz" in the mobile communications industry. One of the terms you'll hear in conjunction with CDMA is "Soft Handoff". A handoff occurs in any cellular system when your call switches from one cell site to another as you travel. In all other technologies this handoff occurs when the network informs your phone of the new channel to which it must switch. The phone then stops receiving and transmitting on the old channel, and it commences transmitting and receiving on the new channel. It goes without saying that this is known as a "Hard Handoff". In CDMA however, every site are on the SAME frequency. In order to begin listening to a new site the phone only needs to change the pseudo-random sequence it uses to decode the desired data from the jumble of bits sent for everyone else. While a call is in progress the network chooses two or more alternate sites that it feels are handoff candidates. It simultaneously broadcasts a copy of your call on each of these sites. Your phone can then pick and choose between the different sources for your call, and move between them whenever it feels like it. It can even combine the data received from two or more different sites to ease the transition from one to the other. This arrangement therefore puts the phone in almost complete control of the handoff process. Such an arrangement should ensure that there is always a new site primed and ready to take over the call at a moment's notice. In theory, this should put an end to dropped calls and audio interruptions during the handoff process. In practice it works quite well, but dropped calls are still a fact of life in a mobile environment. However, CDMA rarely drops a call due to a failed handoff. A big problem facing CDMA systems is channel pollution. This occurs when signals from too many base stations are present at the subscriber's phone, but none are dominant. When this situation occurs the audio quality degrades rapidly, even when the signal seem otherwise very strong. Pollution occurs frequently in densely populated urban environments where service providers must build many sites in close proximity. Channel pollution can also result from massive multipath problems caused by many tall buildings. Taming pollution is a tuning and system design issue. It is up to the service provider to reduce this phenomenon as much as possible. In defense of CDMA however, I should point out that the new EVRC CODEC is far more robust than either of the earlier CODECs. Because of its increased robustness it provides much more consistent audio in the face of high frame error rates. EVRC is an 8 kilobit CODEC that provides audio quality that is almost as good to the older 13 kilobit CODEC. Since CDMA consumes only as much of the "ether" as a user talks, switching everyone to an 8 kilobit CODEC was an inevitable move.
Don't confuse EVRC with the old (and unlamented) 8 kilobit CODEC implemented in the early days of CDMA deployment. That CODEC was simply awful, and very few good things could be said about it. EVRC is a far more advanced compression algorithm that cleans up many of the stability problems inherent in the two older CODECs. The sound reproduction is slightly muddier than the 13 kilobit CODEC, but the improvement in stability makes up for this.Supporters often cite capacity as one CDMA's biggest assets. Virtually no one disagrees that CDMA has a very high "spectral efficiency". It can accommodate more users per MHz of bandwidth than any other technology. What experts do not agree upon is by how much. Unlike other technologies, in which the capacity is fixed and easily computed, CDMA has what is known as "Soft Capacity". You can always add just one more caller to a CDMA channel, but once you get past a certain point you begin to pollute the channel such that it becomes difficult to retrieve an error-free data stream for any of the participants.The ultimate capacity of a system is therefore dependent upon where you draw the line. How much degradation is a carrier willing to subject their subscribers to before they admit that they have run out of useable capacity? Even if someone does set a standard error rate at which these calculations are made, it does not mean that you personally will find the service particularly acceptable at that error rate.
TDMALet's move away from CDMA now and have a look at TDMA. Before we can go any further though, I should note that there are actually three different flavors of TDMA in the PCS market. Each of these technologies implements TDMA in a slightly different way. The most complex implementation is, without a doubt, GSM. It overlays the basic TDMA principles with many innovations that reduce the potential problems inherent in the system. To reduce the effects of co-channel interference, multipath, and fading, the GSM network can use something known as Frequency Hopping. This means that your call literally jumps from one channel to another at fairly short intervals. By doing this the likelihood of a given RF problem is randomized, and the effects are far less noticeable to the end user. Frequency Hopping is always available, but not mandated. This means that your GSM provider may or may not use it. iDEN is a proprietary Motorola technology that no other company seems to participate in. Only Motorola makes iDEN phones, and only Motorola makes iDEN infrastructure equipment. Perhaps the company guards its technology on purpose. iDEN was initially deployed as an alternative to standard packet radio systems commonly used by public safety and business users. However, it also provided phone interconnect services that are extinguishable from phone services offered by the other PCS systems, as well as packet data services for web browsing and hooking up your laptop to the Internet.
Finally there is the old IS-136 technology, but this is now an officially dead technology. All of the North American providers who used it (Rogers, Cingular, and AT&T) are abandoning it in favor of GSM. The same is happening in other parts of the world where IS-136 was used. I therefore will not spend much time talking about this variation of TDMA. Each of these TDMA technologies uses a different CODEC. GSM sports a CODEC called EFR (short for Enhanced Full Rate). This CODEC is arguable the best sounding one available in the PCS world. IS-136 used to sound horrible, but in the fall of 1997 they replaced their old CODEC with a new one. This new CODEC sounds much better than the old, but it doesn't quite match the GSM and CDMA entries. TDMA systems still rely on the switch to determine when to perform a handoff. Unlike the old analog system however, the switch does not do this in a vacuum. The TDMA handset constantly monitors the signals coming from other sites, and it reports this information to the switch without the caller being aware of it. The switch then uses this information to make better handoff choices at more appropriate times.
Perhaps the most annoying aspect of TDMA system to some people is the obviousness of handoffs. Some people don't tend to hear them, and I can only envy those individuals. Those of us who are sensitive to the slight interruptions caused by handoffs will probably find GSM the most frustrating. It's handoffs are by far the most messy. When handoffs occur infrequently (such as when we are stationary or in areas with few sites), they really don't present a problem at all. However, when they occur very frequently (while travelling in an area with a huge number of sites) they can become annoying. Spectral EfficiencyChannel capacity in a TDMA system is fixed and indisputable. Each channel carries a finite number of "slots", and you can never accommodate a new caller once each of those slots is filled. Spectral efficiency varies from one technology to another, but computing a precise number is still a contentious issue. For example, GSM provides 8 slots in a channel 200 kHz wide, while iDEN provides 3 slots in a channel only 25 kHz wide. GSM therefore consumes 25 kHz per user, while IS-136 consumes only 8.333 kHz per user. When Direct Connect is used on iDEN, 6 users can be stuffed into a single channel, thus only 4.166 kHz is consumer per user. There is also a new 6:1 interconnect CODEC coming for iDEN which will allow 6 phone users per channel. One would be sorely tempted to proclaim that iDEN has 3 to 6 times the capacity of GSM. In a one-cell system this is certainly true, but once we start deploying multiple cells and channel reuse the situation becomes more complex. Due to GSM's better error management and frequency hopping the interference of a co-channel site is greatly reduced. This allows frequencies to be reused more frequently without a degradation in the overall quality of the service. Capacity is measured in "calls per cell per MHz". An GSM system using N=4 reuse (this means you have 4 different sets of frequencies to spread out around town) the figure is 5.0 We get an efficiency value of 6.6 fo
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