基于PCF的突发实时访问控制协议

Burst Real-time Access Control Protocal Based on PCF

为了提高大型无线局域网络控制系统中突发性实时数据的实时性,在IEEE 802.11介质访问控制(MAC)协议的基础上提出了一种改进的点协调功能(PCF),即突发点协调功能(BPCF)。在无竞争周期中,依据数据的实时性将周期数据依次轮询传输;依据突发数据产生的时序采取两类不同的策略进行传输,降低了突发性数据的延时,保证了实时数据的延时有界;点协调器循环移动轮询列表中工作站的次序,增加了访问的公平性。分析与仿真表明,BPCF突发性实时数据的平均延时明显低于标准PCF。

To lower the access delay of the burst real-time data in the large wireless local area network（WLAN）control system,a modified point coordination function（PCF）（also burst PCF,BPCF）is proposed based on the IEEE 802.11 media access control（MAC）protocal.The periodic data in the contention free period are transmitted and polled by polling list according to their real-times.Two schemes are adopted to transmit the burst real-time data by their arrival times,the burst data access delay is reduced,and the bound of the real-time access delay is guaranteed.The point coordinator cyclically shifts the station order in the polling list to enhance the access fairness.Simulation and analysis show that the real-time data delay of BPCF is lower than that of the standard PCF burst.