Optimum Allocation Scheme for User Fairness of Location-Based Virtual Sector Method Solving Hidden Terminal Problem in WLAN

The hidden terminal problem degrades the uplink system throughput of wireless local area network seriously. In this paper, we propose the optimum allocation (OA) scheme of the location-based virtual sector (VS) method, which solves the hidden terminal problem without massive overheads like request-to-send and clear-to-send (RTS/CTS) packets. The VS method forms sectors virtually to make short-distance mobile terminal (MT) groups using MTs' location information. In the group, all MTs can sense the transmission of all other MTs. In the proposed method, rough time slot control is implemented for intersector control, which does not need a highly functional centralized controller. The proposal OA scheme of the VS method improves the fairness among MTs by optimizing active periods of VS according to the number of MTs in each VS. By computer simulations, we show that the proposed method can increase the system throughput from the RTS/CTS and improve fairness among MTs even in the condition that positioning error is 1/10 of cell radius.