IMPROVED TOPOLOGY FOR ACHIEVING RELIABILITY IN HIGH-SPEED TREE LANS

The use of a single high speed communication tree as a means of provid ing communication between nodes has recently become common in a local environment. It is known as a Tree Area Network (TLAN). There are seve ral fault-tolerant architectures for TLANs which attempt to increase t he reliability of the simplex tree by introducing extra inter-node lin ks. In this paper, a new fault-tolerant topology is proposed for TLANs with collision avoidance switches and a multiple broadcast facility u sed for high speed lightwave communication. The present approach uses fewer redundant links than those used in an earlier technique(1) to co nstruct the complete link added tree (LAT) architecture, and it is cha racterized by its high degree of fault tolerance and its capability to maintain concurrent transmissions even in the event of multiple failu res at different levels. The scheme is simpler and easier to implement than the existing fault-tolerant TLAN architectures and has reliabili ty comparable with them, as shown by the simulation result of the syst em reliabilities.