Synchronization in packet-based networks: challenges and solutions

Synchronization in packet-based networks pdf

Access transport networks are evolving from dedicated-service, narrowband and highly

bit-optimized PDH/SDH-based networks to multiservice, wideband and over-provisioned

packet-based 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, video on demand (VoD) and 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 multiple services. Apart from providing a stipulated

quality of service (QoS) 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) to

asynchronous transport technologies.