Synchronous Ethernet Timing Solutions -- With Narrow Loop Bandwidth And Ultra Low Output Jitter

By Param Nampoothiri, Valpey Fisher Corporation

Today's consumers demand more bandwidth and faster, more reliable services. Network providers are designing the next generation IP based networks to meet the demand and Ethernet has emerged as the transport medium of choice. Ethernet also gives more flexibility for integrating video, data, and voice.

For more accurate data multiplexing and de-multiplexing, IP based networks have a strong requirement for frequency synchronization across the entire network. SONET based networks have this capability already. A new solution is to take the already popular asynchronous Ethernet Network and synchronize it. This new technology is called Synchronous Ethernet or Sync-E.

Where Synchronous Ethernet (Sync-E) is used:

1. Wireless Backhaul

• For GSM systems; the timing reference has been T1 or E1-based. Bandwidth of these links is saturated due to the new 3G services.
• LTE – next generation wireless protocol.
• Current GPS based systems –moving to Sync-E for frequency reference

2. Metro and Carrier Ethernet

• Circuit Emulation Services
• Digital Video Broadcasting