ON SOME ASPECTS OF RELIABILITY EVALUATION AND OPTIMIZATION OF COMMUNICATION NETWORKS

Abstract

It is needless to impress upon the importance of communication networks which are so vital for the country's economic growth. For efficient and effective transmission and exchange of data, the communication networks must be highly reliable. ?or computer communication networks, the communication network used should be highly reliable for efficient exchange of data between the computers and the users. The first step in this direction, therefore, is the evaluation of reliability of such networks and then to apply optimization techniques for optimal design subject to the resources available. The reliability is characterized by two parameters Terminal Reliability (TR) and Global Reliability (OR) for communication systems. The TR is useful for network analysis whereas OR for network synthesis. PR guarantees that any pair of the nodes in a network* on an average, have a viable connection for the percentage of time not smaller than TR whereas OR guarantee that-all the network users, on an average, may remain connected together for a percentage of time not smaller than OR. The methods have been discussed and developed to evaluate TR and GR. The nodes, which are the switching centres or oommunicaticni centres, may also not be perfectly reliable. Their reli%bility is also considered for evaluation of TR and GR. Optimization technique has been applied to minimize the cost subject to the constraints on reliability. The methods discussed to evaluate TR and OR are applied to the telegraphic network of Roorkee and surrounding centres. The methodology discussed and developed are also applicable to all types of .systems such as complex chemical plants, electronic equipments, national power grid etc.