ATM NETWORK DESIGN AND OPTIMIZATION - A MULTIRATE LOSS NETWORK FRAMEWORK

Asynchronous transfer mode (ATM) network design and optimization at th e call-level may be formulated in the framework of multirate, circuit- switched, loss networks with effective bandwidth encapsulating cell-le vel behavior. Each service supported on the ATM network is characteriz ed by a rate or bandwidth requirement. Future networks will be charact erized by links with very large capacities in circuits and by many rat es. Various asymptotic results are given to reduce the attendant compl exity of numerical calculations. A central element is a uniform asympt otic approximation (UAA) for link analyses. Moreover, a unified hybrid approach is given which allows asymptotic and nonasymptotic methods o f calculations to be used cooperatively. Network loss probabilities ar e obtained by solving fixed-point equations. A canonical problem of ro ute and logical network design is considered. An optimization procedur e is proposed, which is guided by gradients obtained by solving a syst em of equations for implied costs. A novel application of the EM. algo rithm gives an efficient technique for calculating implied costs with changing traffic conditions. Finally, we report numerical results obta ined by the software package TALISMAN, which incorporates the theoreti cal results. The network considered has eight nodes, 20 links, six ser vices, and as many as 160 routes.