Communications systems

Abstract From the Canadian patent

A communications network comprises a plurality of stations which can communicate via a ring. Information is transmitted from one station to another in message blocks which circulate around the ring. The message blocks include control bits and a protocol is employed which ensures that no one station can monopolise the available message blocks. Also described is a technique which allows each station independently to assess the current spare capacity of the network. A link multiplexer may be used in conjunction with rings and incorporates a similar protocol. It provides access to a link to queues of message blocks provided queue thresholds have not been reached.