A communications system suitable for use as a local area network (LAN) is provided wherein the network has a ring topology comprising a plurality of nodes 10 each of which is connected to adjacent nodes by links 14 and 15. Each node comprises a Link Interface Unit (LIU) 11, a Network Interforce Unit...http://www.google.com/patents/US4663748?utm_source=gb-gplus-sharePatent US4663748 - Local area network
