Performance Evaluation in Multi-Rate, Multi-Hop Communication Networks
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, and thus impractical for online evaluation or when it comes to sensitivity analysis or network optimization because of the large amount of simulation runs it requires. A particular performance metric of interest is the end-to-end blocking probability in a circuit- switching loss network. Various analytical approaches and approximation schemes have been suggested and among them, the fixed-point method, or reduced load method, has been receiving much attention. However, most of these schemes either consider only single traffic rate situation or multi-rate traffic under fixed routing. After a brief review of the reduced load approximation, we propose 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. Examples of applications are also provided in which the proposed scheme is linked to the optimization tool CONSOL-OPTCAD to get network design trade-offs.