Joint Routing, Scheduling and Admission Control Protocol for WiMAX Networks

In WiMax networks the routing and the scheduling are tightly coupled. The routing and scheduling problem for WiMAX networks is different from 802.11 based mesh networks and can be designed and operated separately. Standard problems in wireless systems include Bandwidth allocation and Connection Admission Control (CAC). In this paper we design a joint routing, scheduling and admission control protocol for WiMax networks. In the adaptive scheduling, packets are transmitted as per allotted slots from different priority of traffic classes adaptively, depending on the channel condition. A bandwidth estimation technique is combined with route discovery and route setup in order to find a best route. The admission control technique is based on the estimation of bandwidth utilization of each traffic class, with the constraint that the delay requirement of real-time flows should be satisfied. The current available bandwidth is estimated for all the nodes and for the new incoming flows, it estimates the requested bandwidth and decides to admit this new flow or not. By simulation results, we show that our proposed protocol achieves better throughput and channel utilization while reducing the blocking probability and delay.