(A) capacity allocation problem in voice/data integrated networks using fuzzy approach

Abstract

This thesis deals with the problem of allocating time slots between voice and data traffic which is one important design issue for an integrated voice/data digital network. One difficulty in the analysis of the integrated system is that due to the different characteristics, two types of traffic require different performance criteria, blocking probability for voice and average delay for data. Moreover, the two criteria are even conflicting in the sense that the larger capacity voice is allocated, its blocking probability decreases while the average delay increases, and vice versa. Motivated by this observation, the capacity assignment problem is formulated as a multiobjective optimization model, which seeks to achieve both performance criteria at their highest possible values. The principal aim of this thesis is then to identify such an ``efficient`` solution whereby the blocking probability for voice and the average delay for data are optimally traded off. Among several known approaches, we employed the fuzzy set-theoritic approach mainly due to its simple but effective way of handling the imprecise nature of the decision maker``s judgement. Another contribution of this study may be, besides providing an efficient compromise allocation trunk capacities in a voice/data integrated network, in shedding light on the potential of fuzzy set theory as a powerful vehicle for the analysis of those communication systems with multiple performance criteria.