Dynamic TXOP Assignment in IEEE802.11e Multi-hop Wireless Networks Based on an Admission Control Method

There is no network traffic classification in intermediate nodes in IEEE802.11e multi-hop wireless network, which results in delays for the traffic with higher levels of service. Also, there is no mechanism to support fairness in a shared environment with different classes of service, which leads to inappropriate quality of service. Previous studies were focused on improving network throughput and also the fairness among the traffic that belongs to one class of service and there is no solution for providing fairness among different classes of service in each individual node. In this paper, a new method is proposed for scheduling the traffic in each intermediate node which is based on Transmission Opportunity (TXOP). The new method ensures differentiated quality of service for service classes as well as improvement of throughput and end to end delay. Using dynamic TXOP along with the proposed method can provide desired quality of service as well as fairness in the bandwidth shared between different classes of services. Simulation results illustrate network throughput and end to end delay improvement for each class of service, in the case of using the proposed method, as well as fairness in using the shared bandwidth which leads to more efficient use of network resources.