摘要 |
A communications network comprises a plurality of stations (10) which can communicate via a ring (11). 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 (30) may be used in conjunction with rings (11) and incorporates a similar protocol. It provides access to a link (40) to queues of message blocks provided queue thresholds have not been reached. |