A resource management strategy for multimedia adaptive-rate traffic in a wireless network with TDMA access

One of the challenges today for wireless network operators is to find techniques which will make it possible to introduce multimedia capabilities into mobile communications. The application of a wireless network structure made up of pico-cells to solve this problem will cause an increase in the handover rate. Therefore, a major requirement in a wireless environment is to design an effective call admission control (CAC) strategy to minimize the handover drop probability. Another important requirement is to maximize network utilization in terms of the mean number of channels used. The goal of this paper is to define a resource management strategy for heterogeneous adaptive-rate traffic. The proposed strategy is actually a combination of two: a CAC management strategy and a bandwidth management one. The CAC management strategy extends the Guard Channel strategy to obtain priority-based CAC management for adaptive-rate sources; the bandwidth management strategy allows channels to be assigned proportionally to the throughput window declared by users. In order to assess the effectiveness of the proposed CAC strategy, two Markov models of the system are introduced: one, from the network point of view, to evaluate global system performance, and another, from the user point of view, to evaluate the performance each user is provided with by the network. Numerical examples conclude the paper to analyze which factors most affect performance when the source rate is adaptive and the proposed admission strategy is applied.