Analysis of Dependence Effects in Telephone Trunking Networks

The exact analysis of telephone trunking networks often leads to severe computational problems due, e.g., to the large number of possible states. Approximate methods are thus naturally used. There has been much success in approximately calculating link blocking probabilities but less in determining point-to-point blocking probabilities. Errors in the pointto-point blocking probabilities can be caused by independence assumptions. The purpose of this paper is to take advantage of existing techniques for approximating link blocking probabilities (which are quite accurate) and develop an approach for taking link dependences into account. In particular, we present a method for approximating the appropriate conditional probabilities for cases where the traffics are Poisson (or close to Poisson). The extension of the approach to the case of distinctly nonPoisson processes, such as arise in overflows, will be reported in Ref. 1. To obtain point-point blocking probabilities for non-Poisson processes, * We use link to denote trunk group. 2647