Fair Queuing Model for EDCA to Optimize QoS in Ad-Hoc Wireless Network

摘要

This study aims to develop and optimize the quality of service (QoS) with fairness in multi-hop wireless adhoc networks. IEEE802.11e (EDCA) standard is concerned to support QoS in wireless adhoc networks. Thereby, EDCA differentiates and classifies the packets in access categories depending on their priorities. However, it cannot guarantee strict QoS required by real-time and multimedia services without proper network control mechanisms. And also, the unfairness of bandwidth sharing ,because of the hidden and exposed terminals problems, leads to degrade the guarantee services. Our proposition (FQ-EDCA) is to enhance the QoS of EDCA by implementing a fair queuing scheduling technique and improving the architecture of EDCA scheme. FQ-EDCA is proved and analyzed by experimental simulations for many topologies like (star, chain, tree, ...). Thus, the bandwidth is distributed fairly between all the source nodes. As a consequence, these nodes can access the channel fairly to transmit their flows with respect to EDCA specifications of access categories (AC) priorities. And also, the delay of flows of the same priorities is minimized and nearly fixed for all the source nodes. This leads to minimize the jitter also. Therefore, the services guarantees of QoS is enhanced.