The Performance Analysis of Direct/Cooperative Transmission with TXOP Scheme in WLANs

In this paper, we evaluate the saturation throughput and saturation delay with direct/cooperative transmission strategies. Moreover, the cost function is introduced to tradeoff the system performance to determine the optimal strategy for adopting the cooperative transmission, and then we extend the model to support applications with quality of service (QoS) requirements. In order to improve the efficiency, TXOP mechanism which allows multiple consecutive frame exchanges during the TXOP duration is defined in IEEE 802.11e standard. We show the performance in term of saturation throughput, saturation delay and total throughput of the model. Numerical results show that TXOP mechanism is generally suitable for high traffic condition environments.