Taking time across the network

There have been several new multiplexing proposals that have crated considerable interest because of their claims to do things so much better than the old methods. The old methods very often have useful characteristics, that many users of telecommunications are reliant on, but which sometimes are not very well specified. The author looks at some very basic requirements of large digital telecommunication networks that all general multiplexing methods must be able to satisfy, and explains the significance of accurately transporting timing information. Taking time across the network is a very fundamental requirement for telecommunication networks and all new general multiplexing methods must provide low phase distortion transmission. New multiplexing standards must take account of the real nature of the traffic to be carried. In developing its synchronous digital hierarchy products, GPT is making allowance for phase critical payloads by offering novel solutions to the attendant problems