TeleEducation

PDH

Incompatibility of “standard” equipment from different vendors
US and European systems have too little in common - Expensive mediators for transatlantic transmission
No self checking - expensive manual check and repair system
No standard for high bandwidth links - proprietary

SDH (Standard Approval by the CCIT

The Main Standards

G.707 , G.708 , G709 (G.707/Y SINCE 96/93)

Transmission rates
Signal format
Multiplexing structures
Tributary mapping for the network node interface

G782 (Merge with G.783 in 97) , G.783

Operation of synchronous multiplexers

G.781

SDH synchronization networking

G.784

SDH network management

The SDH Advantages:

High transmission rates

Lower level signals embedded and can be identified from the higher level (much simpler Add & Drop)

Optical standard

Can be introduced into existing networks Allowance of European and North American PDH systems

More of the SDH Advantages:

High availability and capacity matching
Reliability
Centralized synchronization
Network management channels (the data used for maintenance is embedded in the signal)
Centralized network control enabled through the management channels

Management Functions

Alarm / Event Management
Configuration Management
Performance Management
Access and Security Management