DROP/INSERT MULTIPLEXER FOR DATA CHANNEL ACCESS UNITS

摘要

An improved drop/insert multiplexer for use in a channel access unit that uses channel slots in common for data channels in first and second directions, and uses less wiring between a multiplexer/de-multiplexer section and a channel section thereof is provided by adopting a time division multiplex transmission system for transmitting receive and send channel pulses. The drop/insert multiplexer has at the receive side thereof, a time slot phase difference setting stage for providing a predetermined phase difference between received timing signals as well as receive data from the first and second directions. A receive channel pulse generating stage generates multiplexed channels pulses. A receive channel pulse decoding stage and a PCM decoder reproduces a voice signal by receiving selected received data and, at the send side thereof, a time slot phase difference correcting stage corrects the set phase difference for sending out channel data to the first and second directions. A send channel pulse generating stage generates multiplexed channel pulses. A send channel pulse decoding stage and a PCM coder produces PCM signals to send out to the first and second directions as channel data.