madhuvarsha
2010-12-15, 12:59 AM
Synchronization in packet-based networks: challenges and solutions pdf (http://m2vtelecom.blogspot.com/2010/12/synchronization-in-packet-based.html)
Access transport networks are evolving from dedicated-service, narrowband (http://en.wikipedia.org/wiki/Narrowband) and highly bit-optimized PDH/SDH-based networks to multiservice, wideband and over-provisioned packet-based (http://en.wikipedia.org/wiki/Packet_switching) networks. At the same time,the demand for greater bandwidth continues to grow unabated. This demand is being fueled by fi xed and mobile broadband as well as offerings such as IPTV (http://en.wikipedia.org/wiki/IPTV), video on demand (VoD) and peer-to-peer (http://en.wikipedia.org/wiki/Peer-to-peer) services.
For high-capacity low-cost services to be commercially viable, operators must decrease their per-bit production costs. Accordingly, access networks are destined to become large bit pipes for transporting (http://www.wikinvest.com/industry/Transportation) multiple services. Apart from providing a stipulated quality of service (QoS (http://en.wikipedia.org/wiki/Quality_of_service)) and standard traffi separation, they will offer very little functionality. To enable the use of standard, cost-effective transport equipment, the
services that use access networks may put only limited requirements on transport. The passing of reference synchronization sources over transport networks also becomes an issue as operators move fromtime division multiplexing (TDM (http://en.wikipedia.org/wiki/Time-division_multiplexing)) to asynchronous transport technologies.
Access transport networks are evolving from dedicated-service, narrowband (http://en.wikipedia.org/wiki/Narrowband) and highly bit-optimized PDH/SDH-based networks to multiservice, wideband and over-provisioned packet-based (http://en.wikipedia.org/wiki/Packet_switching) networks. At the same time,the demand for greater bandwidth continues to grow unabated. This demand is being fueled by fi xed and mobile broadband as well as offerings such as IPTV (http://en.wikipedia.org/wiki/IPTV), video on demand (VoD) and peer-to-peer (http://en.wikipedia.org/wiki/Peer-to-peer) services.
For high-capacity low-cost services to be commercially viable, operators must decrease their per-bit production costs. Accordingly, access networks are destined to become large bit pipes for transporting (http://www.wikinvest.com/industry/Transportation) multiple services. Apart from providing a stipulated quality of service (QoS (http://en.wikipedia.org/wiki/Quality_of_service)) and standard traffi separation, they will offer very little functionality. To enable the use of standard, cost-effective transport equipment, the
services that use access networks may put only limited requirements on transport. The passing of reference synchronization sources over transport networks also becomes an issue as operators move fromtime division multiplexing (TDM (http://en.wikipedia.org/wiki/Time-division_multiplexing)) to asynchronous transport technologies.