SYNCHONOUS OPTICAL NETWORK

Synchronous Optical Network is called as SONET.SONET is a high bandwidth fiber cable network.
A clock is used here for synchronizing the pulses. It uses time division multiplexing which is controlled by the master clock.the devices of SONET are

1. STS multiplex\demux
2. Regenerator
3. Add/Drop multiplex

This SONET also has a frame. the frame is the matrix of 90octets*9rows.It also includes SPE called as Synchronous payload envelope.The physical links for each STS level is called as optical carrier.