RELIABILLTY OF LOOP COMMUNICATION NETWORKS.

The loop communication network is a network with transmission links arranged in the form of a loop shared by many terminals and is intended to achieve flexibility of system configuration and efficiency in traffic handling. This type of network has the disadvantage that a fault at one point may have a significant effect over a wide range. As a means to avoid this situation, this paper discusses improvement of the system reliability by distributing and decreasing the effect of a fault by providing redundancies in the network construction. Eight methods of communication network construction are proposed. For each of those networks, the relation is derived between the fault probability of an element and the system reliability. By numerical calculation, the reliability of each type of network is discussed along with its applicable range.