Performance Evaluation in Multi-Rate, Multi-Hop Communication Networks with Adaptive Routing

Accurate performance evaluation has always been an important issue in network design and analysis. Discrete event simulation has been known to be accurate but very time consuming. Thus analytical methods/approximation is necessary for real time estimation, large scale network optimization and sensitivity analysis. In a circuit-switched loss network, a particular performance metric of interest is the end-to-end blocking probability. Various analytical approaches and approximation schemes have been suggested for this problem and among them, the fixed-point method, or reduced load method, has  received much attention. However, most of these schemes either consider only single traffic rate situations or multi-rate traffic under fixed routing. We develop an approximation scheme to estimate end-to-end blocking probability in a multi-rate multi-hop network with an adaptive routing scheme. The approximation results are compared with that of discrete event simulation. An example of application is also provided in which the proposed scheme is linked to the optimization tool CONSOL-OPTCAD to get network design trade-offs. The method described here is readily applicable to accurate performance evaluation of military networks which are often large and hybrid.