An Improved Polling Scheme for PCF MAC Protocol
Qianlin Liu, Dongfeng Zhao, Hongwei Ding · 2011
The design of media access control (MAC) protocol that can efficiently support the real-time applications in Wireless Local Area Networks (WLANs) requires that the MAC layer provide strict delay guarantees for sensitive traffic, the Point Coordination Function (PCF) with Round Robin (RR) polling scheme has been included in IEEE 802.11 MAC protocol to achieve this objective. This paper uses two-level-polling scheme to improve the performance of RR scheme, and the closed form expressions for the mean cyclic period (MCP), the mean queue length (MQL) and the mean waiting time (MWT) of the scheme have been obtained, the analytical results are also verified through extensive computer simulations. The comparison results show that the efficiency as well as impartiality of proposed scheme is better than that of the RR scheme.