“Infrastructure for Transport of Multimedia Applications to the End User” Access Network Architectures and High Speed Access Technologies

Summary What are access network options that would be used by different multimedia services providers to carry the multimedia applications to the end users? What are access network options that would be used by different multimedia services providers to carry the multimedia applications to the end users? Where we stand regarding deployment of numerous DSL and cable modem technologies? Where we stand regarding deployment of numerous DSL and cable modem technologies? What are the most suitable DSL technologies and why? What are the most suitable DSL technologies and why? How these technologies are deployed in practice? How these technologies are deployed in practice?

Summary Contd.. How much the current infrastructure is ready for them How much the current infrastructure is ready for them What are the considerations for the success and acceptance of the end user for delivery of multimedia services over the these technologies. What are the considerations for the success and acceptance of the end user for delivery of multimedia services over the these technologies.

Few questions to gain perspective?? What is a multimedia application? What is a multimedia application? What is meant by triple play? What is meant by triple play? How much you know about access networks and their capabilities? How much you know about access networks and their capabilities? What is a DSL network? What is a DSL network? What is a Cable network? What is a Cable network? What is the difference between an ATM and IP network? What is the difference between an ATM and IP network?

Application Characteristics from Physical Transport Perspective Three main features for Physical Transport from an application’s perspective. Three main features for Physical Transport from an application’s perspective. –Bandwidth required –Delay or Latency accepted –Bit Error Ratio A suitable access network to provide multimedia application needs to provide sufficient bandwidth, necessary BER and data transport delay A suitable access network to provide multimedia application needs to provide sufficient bandwidth, necessary BER and data transport delay

Access Networks Traditional networks are copper loop networks providing POTS telephone service and then Coaxial Cable networks providing broadcast video service Traditional networks are copper loop networks providing POTS telephone service and then Coaxial Cable networks providing broadcast video service –Both of these were analog –Multiplexing different applications was difficult if not impossible –Access networks need to be digital to multiplex applications –Next generation Access networks were digital but lacked sufficient bandwidth for Video applications. –Latest Access Networks provide for the bandwidth but are costly to deploy

Dilemma for Access Network Upgradation Who pays for it? Why a service provider should invest? Who pays for it? Why a service provider should invest? –Given multimedia services are not necessarily yet a need in society, & multimedia services are not necessarily yet a need in society, & Subscription is a function of economic development of the society Subscription is a function of economic development of the society –Societies being economically developed should be able to deploy and subscribe –But What to do with the existing infrastructure What to do with the existing infrastructure –Societies less economically developed are making green field deployments and can start with Triple play support. But there are not many who have extra money to enjoy the service

DSL System Model Ethernet PHY IEEE MAC ADSL PHY ATM-TC TCP/IP - DHCP etc. (rout. fun.) ATM AAL5 UTOPIA App. Sp. AL/ PPP-o-ATM ADSL PHY ATM-TC ATM UTOPIA PHY USBADSL PHY ATM-TC ATM ADSL PHY ATM-TC ATM PHY USB CDC 1.1USBD CDC1.1 ATM RFC 1483 ATM mini port I/F LAN mini port I/F USB Cable ATM Network Access Network DSLAM/ATM Switch USB DSL Modem Ethernet DSL Modem DSLAM/ATM Switch AAL5 Ethernet PHY IEEE MAC TCP/IP Centillium CO Chip Centillium CPE Chip

HFC Network Headend ATM Network Headend CATV Network Cable Modem CATV Network Cable Modem

Observations on HFC Networks Shared medium like LAN so bandwidth guarantee issue Shared medium like LAN so bandwidth guarantee issue Return path bandwidth Issue for legacy reasons Return path bandwidth Issue for legacy reasons Point-to-multipoint signaling issue if using ATM transport over HFC networks Point-to-multipoint signaling issue if using ATM transport over HFC networks

Full Rate ADSL ADSL - Asymmetric Digital Subscriber Line ADSL - Asymmetric Digital Subscriber Line Supports asymmetric rates on medium loops Supports asymmetric rates on medium loops Application focus is both business and residential Application focus is both business and residential Typical rates: Typical rates: –6 Mbps Down /0.5 Mbps 9 kft Issues with Full Rate ADSL Issues with Full Rate ADSL –Late deployment –dual latency –power consumption –POTS Splitter –coverage

Splitterless ADSL Lite Supports asymmetric rates on long loops Supports asymmetric rates on long loops Addresses the main Issues with Full Rate ADSL Addresses the main Issues with Full Rate ADSL –single latency –reduced complexity, hence low power consumption –no home rewiring –extended coverage –no POTS splitter fast retrain procedure fast retrain procedure

SHDSL Technology SHDSL - Single-pair High-Speed Digital Subscriber Line SHDSL - Single-pair High-Speed Digital Subscriber Line Supports symmetric rates; 192, 256, 384, , and 2304 kbps on moderate to long loops Supports symmetric rates; 192, 256, 384, , and 2304 kbps on moderate to long loops Application focus is on business, residential office and telecommuters Application focus is on business, residential office and telecommuters Uses Trellis coded PAM line code Uses Trellis coded PAM line code Echo cancellation is required as both directions use the same frequency band Echo cancellation is required as both directions use the same frequency band Spectrally compatible with other DSL systems with some reach restrictions at different rates Spectrally compatible with other DSL systems with some reach restrictions at different rates Low symmetric rate may compete with ADSL service Low symmetric rate may compete with ADSL service Initially SHDSL service is expected to be costlier than ADSL Initially SHDSL service is expected to be costlier than ADSL Draws from ANSI HDSL2 and ETSI SDSL standards Draws from ANSI HDSL2 and ETSI SDSL standards

VDSL Technology VDSL - Very-high-speed Digital Subscriber Line VDSL - Very-high-speed Digital Subscriber Line Supports both symmetric and asymmetric rates on much shorter loops Supports both symmetric and asymmetric rates on much shorter loops Application focus is both business and residential Application focus is both business and residential Keyword is “Video Delivery” Keyword is “Video Delivery” Typical rates: Typical rates: –Asymmetric; 52 Mbps Down /6.4 Mbps 1 kft 52 Mbps Down /6.4 Mbps 1 kft 26 Mbps Down /3.2 Mbps 3 kft 26 Mbps Down /3.2 Mbps 3 kft 13 Mbps Down /1.6 Mbps 4.5 kft 13 Mbps Down /1.6 Mbps 4.5 kft –Symmetric; 26 1 kft 26 1 kft 13 3 kft 13 3 kft kft kft

VDSL Technology - Access Network Growth Access Network DSLAM/ATM Switch DSL Modem Copper Access Network DSLAM/ATM Switch DSL Modem DSLAM/ATM Switch DSL Modem DSLAM/ATM Switch Fiber Modem Copper Access Network FTTN - Fiber to the Neighborhood FTTC Fiber to the Curb FTTH Fiber to the Home

Conclusions

Conclusions Quality multimedia applications would only be possible with VDSL type technologies with new deployments Quality multimedia applications would only be possible with VDSL type technologies with new deployments Issues to be resolved are everywhere in the protocol stack Issues to be resolved are everywhere in the protocol stack