MULTIPLEX ACCESS COMMUNICATION SYSTEM

摘要

A multiple-access communications system for an unlimited user population wherein a system controller continuously transmits Aloha signals on a slot-by-slot basis giving an updated number of time slots available whereby a calling party can select any one of the designated time slots at random. The calling party checks the time slot immediately preceding its selected time slot to ascertain if the current Aloha number is zero (or an equivalent thereof). If it is zero then the calling party reverts to listening for a time slot containing an Aloha number greater than zero. Alternatively if it is not zero the calling party apparatus sends a signal to the system controller in its selected time slot. Multipurpose signalling in each time slot can be carried out by the system controller thereby reducing the overhead on the system and speeding-up the setting-up of calls which may be off-air or non off-air.