Performance approximations for non-real-time traffic in an integrated service system

We consider an integrated service system, where real-time (RT) calls of multiple rate requirements and non-real-time (NRT) calls share the total system capacity. Typically, RT calls are given strict priority over NRT calls, therefore, NRT performance is dependent on the RT process. When RT call arrival processes are not Poisson processes, the effect of the RT traffic burstiness on the NRT performance has not been investigated. In this paper, we investigate the effect and provide a computationally efficient approximation for the NRT performance evaluation in the integrated service system with multi-rate non-Poisson RT traffic. With known first and second moments of the RT call arrival processes, we propose to consider the multi-rate non-Poisson RT traffic streams as an equivalent single-rate Poisson traffic stream. Then we evaluated the NRT performance by converting the original system to a system offered with the equivalent RT traffic and the NRT traffic. Our approximation is validated with extensive numerical examples.