QoS routing in mobile ad hoc networks based on the enhanced distributed coordination function

This paper proposes a QoS routing protocol for multimedia services in mobile ad hoc networks (MANETs). We adopt a new distributed MAC protocol, called enhanced distributed coordination function (EDCF), that has being developed by IEEE 802.11 working group to support service differentiation. In order to satisfy the QoS requirements such as required bandwidth and end-to-end delay for different source-destination transmission pairs, it requires a QoS routing protocol to find routes with QoS guarantees. The proposed QoS routing protocol discovers routes for source-destination transmission pairs with bandwidth and end-to-end delay guarantees. The procedures of neighborhood maintenance, QoS violation detection, and route maintenance are also presented in this paper. Furthermore, we introduce a new problem called hidden route problem, which is arising because of existing routes that are hidden for the current route discovery procedure. The problem is also solved in the proposed QoS routing protocol. We use the ns-2 simulation to evaluate the performance of the proposed QoS routing protocol and compare it with other ad hoc QoS routing protocols. Simulation results show that the performance criteria, such as packet delivery ratio and average end-to-end delay, outperform other existing QoS routing protocols with the sacrifice of routing overhead under light load conditions.