IEEE 802.11无线局域网中一种上下行带宽分配策略

针对IEEE 802.11基础架构网络中上下行带宽分配不公平的问题，提出一种新的基于概率发送机制的MAC层解决方案。该方案通过调节分组传输的概率改变AP或终端的接入概率，从而实现上下行带宽的公平分配。本文首先推导出了公平带宽分配的最优传输概率与下行流数的关系，并据此提出两种可分别在AP或终端实施的策略。仿真结果证实了分析模型的正确性，同时表明该策略能够提供较准确的上下行带宽分配。

Bandwidth Allocation Scheme between Uplink and Downlink in IEEE 802.11 WLAN

In 802.11 infrastructure BSS, DCF channel access rules based on the per-station fairness leads to unfairness between uplink and downlink flows. In this paper, we propose a novel bandwidth allocation to enhance IEEE 802.11 at MAC layer. With this scheme, the probability that the sender initiates transmission is tuned dynamically, which allows the access probabilities of the access point (AP) and wireless terminals to adapt to the number of downlink flows. By means of an analytical model, we derive the rule achieving the fair bandwidth allocation. Then, according to the obtained rule, two algorithms that can be implemented at AP or wireless terminals are proposed respectively. The simulation results validate the accuracy of the rule and show that the proposed scheme can ensure an adequate level of fairness between uplink and downlink flows.