| Nowadays, the wireless network technology has been wieldy use in many fields. Moreover, the explosive growth of new applications requires the wireless network to provide higher speed. However, the engineers found that, even to significant increased the data rate in the PHY the fixed overhead in the MAC protocol was dragged the system throughput.In this paper, we first introduce the IEEE 802.11 wireless network Medium Access Control (MAC) protocols. Then we analyze the limitations of the current protocols and propose a novel mechanism to improve the performance of the MAC protocol. A simulation platform according to the mechanisms mention above are constructed in Matlab environment and access delay, packet loss rate and throughput under different situations are presented. The main contributions in this paper are showed as following:(1) We propose a novel mechanism for the centrally controlled channel access (CCCA) in the IEEE 802.11 medium access control (MAC) protocol. This mechanism effectively combines the collision free with the fairly apportioning bandwidth based on demand. It eliminates channel sensing, as well as substitutes distributed inter-frame space (DIFS) for short inter-frame space (SIFS) during the transmission period. Moreover, our mechanism successfully circumvents the hidden terminal problem.(2) We described the novel mechanism and the simulation process in detail. The difference between the current method and the novel mechanism of the throughput, access delay, delay variance, and packet loss rate are presented. Our simulation results confirm that our mechanism can improve the networks throughput, while the average delay and the number of packet collisions has also been reduced by applying our design.(3) We propose an easy and effect way to achieve the Quality of Service (QoS) classified service. Different priorities data are served well according the requirement of QoS guarantees by apply the novel mechanism. |
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