IEEE 802.11无线局域网中分布式协调功能的改进

Improvement of distributed coordination function in IEEE 802.11 WLANs

结合无线局域网和TCP的特点提出了一种改进算法,当AP向无线节点发数据包时,无线节点用一个小的数据包(如:TCP层的ACK等)来代替CTS,这样可以避免无线节点单独发送小数据包,从而提高无线信道的利用率和无线网络的吞吐率。从试验结果可以看出,改进后的DCF协议不仅提高了信道的利用率和无线局域网的性能,而且更好的维护了无线节点间的公平性。

In this paper, the standard DCF protocol was modified to achieve efficient channel utilization and improve the performance of WLANs. In our modified DCF, the wireless station sends a small data packet (e.g., ACKs of TCP layer) instead of CTS to reply the RTS of AP. In this way, transmitting small packets separately in WLANs was avoided and also the number of CTS packets in WLANs was decreased. Therefore, the channel utilization rate was increased. The simulation results show that our modified DCF can consistently achieve higher throughput and maintain better fairness among all mobile stations than the standard DCF.