Dynamic Sensitivity Control Based on Two-Hop Farthest Terminal in Dense WLAN

Abstract

The explosive usage of IEEE 802.11 Wireless Local Area Network (WLAN) has resulted in its dense deployments and excessive interference between Basic Service Sets (BSSs) in urban area such as an apartment building and an airport. Serious problems of hidden/exposed terminal in high-density condition negatively impact system throughput. To improve the system efficiency, IEEE 802.11ax TG has been assembled. TG aims at realizing High-Efficiency- WLAN (HEW) by utilizing special reuse technologies including Dynamic Sensitivity Control (DSC), Transmit Power Control (TPC), and BSS Color Filtering (BCF). In this paper, we propose a DSC based on two-hop farthest terminal for dense WLAN. This scheme with minimum transmission power resolves the hidden terminal problem. Propagation loss of received signal from associated communication pair is used for the proper values of transmission power and carrier sense level. Furthermore, adjusting these parameters destination by destination can reduce exposed terminals effectively. We evaluate the performance of the proposed scheme in residential building scenario with three criteria, aggregate throughput, fairness and frame error rate. Simulation results show that the proposed scheme can improve aggregate downlink throughput and fairness compared to previously proposed method that carrier sense level is set based on expected RSSI level of received packet from communicating pair. Furthermore, improvement of frame loss rate implies that the hidden terminal problem can be solved by the proposed scheme.