【摘要】 论文提出一种PCF的改进方案VPCF,提升竞争阶段非实时数据的传输性能。站点在无竞争阶段被轮询时向点协调者捎带将在竞争阶段传输的帧的退避计时器值;点协调者通过比较退避计时器值预见站点间的冲突并告知站点,采用一种称为虚冲突的机制避免站点冲突的发生。仿真表明,VPCF在不影响无竞争阶段实时数据发送的前提下减少了竞争阶段的冲突次数,提高了非实时数据的吞吐量。更多还原

【Abstract】 This paper proposes an enhanced PCF named VPCF,VPCF improve the non-real time traffic transmission in contend period.Been polled in contention free period,stations piggyback the backoff timer’s values of the frames send in the coming contention period.By comparing the backoff timer’s values,point coordinator foresees and announces the collisions between stations.Stations that will collide with others use a mechanism named virtual collision mechanism(VCM) to avoid collisions.The performance of VPCF has been investigated by simulations.Results show that,in contention period,VPCF outperforms the PCF in terms of channel throughput efficiency and collision rate while does not impact the real-time traffic transmissions in contention free period.更多还原