Transmission Queuing Schemes for Improving Downlink Throughput on IEEE 802.11 WLANs

This paper proposes a scheme to solve issue of unfair throughput by the capture effect. Wireless LAN (WLAN) systems suffer from the hidden terminal problem, which is occurred by the unreached signal for non-neighbor radio terminals. Since the CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) for WLANs does not adequately solve this problem, transmitted packets collide more frequently than is desirable, which degrades the throughput performance. Moreover,the differences in distance between terminals can trigger the near-far problem. The near-far problem emphasizes the reception of the strongest signal over weaker signals due to the capture effect. In environments that exhibit both the hidden terminal problem and the near-far problem, there arises the possibility of unfair transmission among the terminals. We propose a scheme that ensures fairness in terms of throughput.