Multiple access system for communications network

摘要

A communications access network comprising a combination of fibre and co-axial cable to the home having co-axial cable deployed in the home comprises a head end, to which outstations are coupled via an optical fibre medium incorporating a star coupler or splitter. The head end is arranged to transmit downstream to the outstations a sequence of frames comprising data frames and command frames. The command frames comprise first and second frames and provide marshalling control of upstream transmissions from the outstations. The first command frame incorporates a global command to all outstations to pause upstream transmission for a pre-set time period. The second command frame is transmitted within the pre-set period and incorporates a further pause command having an associated zero time period and addressed to a selected outstation overriding said global command thus allowing that one selected outstation to transmit to the head end.