Evaluation and comparison of resource allocation strategies for new streaming services in wireless cellular networks

Since a long time wireless networks have been offering two types of services: variable bit-rate such as mail and constant bit-rate such as voice. Recently they also offer service for streaming calls such as mobile television. The objective of the present paper is to study the problem of allocating (and sharing) the resources for this new type of calls and to compare the performance of different allocation strategies. The allocation strategy implemented in real networks is an iterative time-sharing strategy. We build an explicit formulation of this strategy which permits not only a faster implementation, but also an analytical evaluation of its performance. Moreover we describe an optimal allocation strategy consisting of assigning the resources in priority to the least consuming ones. A cornerstone to evaluate and compare the different allocation strategies is the so-called outage probability defined for each location as the probability that a user in this location doesn't get his required bit-rate. We compare the efficiency of different numerical methods to calculate it; and show that the inverse Laplace method is rapid and efficient. We also calculate the increase of the outage probability of the time-sharing strategy compared to the optimal one. Finally, we validate a method permitting to calculate analytically the average of the outage probabilities over the different locations.