Mobility sensitive QoS provisioning in wireless cellular network

Seamless Quality of Service (QoS) guarantees to mobile users in a wireless cellular network are provisioned by employing various bandwidth reservation based methods. However, reservation based schemes suffer from poor utilization since predicting resource demand is difficult owing to mobility induced uncertainties. We present mechanisms and strategies to improve the performance of such reservation based schemes using efficient characterization of user mobility profile at intercellular level.; First we consider the problem of minimizing the resources reserved on time domain. We propose an optimal algorithm for minimizing the reserved resource based on measured statistics such as user arrival and residence time distribution functions in a cell. We next consider the problem of fragmentation in the time domain of reservation space and present certain heuristic based approaches towards reducing such fragmentation. For faraway cells, mobility related uncertainties maybe too high to risk maintaining explicit reservation states and thereby lowering the utilization. In order to increase the utilization; we present a concept of using implicit states based on probabilistic bandwidth allocation. We further extend the concept of implicit states to the case of bandwidth adaptive applications. We show that implicit states can effectively provide probabilistic bounds to the levels of degradation for adaptive applications while achieving high network utilization.; We finally present a dynamic QoS provisioning strategy based on capturing the spatial mobility of users. This strategy by effective call admission control removes hot spots (over congested cells) without sacrificing on the utilization. The performance evaluation shows effectiveness of the scheme under various mobility patterns in providing better level of QoS to users.