IEEE 802.11 무선 랜에서 성능 향상을 위한 채널 예약 기반 DCF MAC 프로토콜

Abstract

In the IEEE 802.11 DCF (Distributed Coordination Function) protocol, the binary exponential backoff algorithm is used to avoid data collisions. However, as the number of stations increases of, the collision probability tends to grow and the overall network performance is reduced. To solve this problem, this paper proposes a data transmission scheme based on the channel reservation method. In the proposed scheme, channel time is divided into reservation period and contention period. During the reservation period, stations succeeded in channel reservation transmit their own data packets in sequence without contention. During the contention period, each station sends its data packets through contentions as in DCF. During both the reservation period and the contention period, each station sends a request for channel reservation for the next reservation period to an AP (Access Point). After receiving such a channel reservation request from each station, the AP decides whether the reservation is succeeded and sends the result via a beacon frame to each station. Performance of the proposed scheme is analyzed through simulations. The simulation results show that the proposed scheme tends to reduce the collision probability of DCF and to improve the overall network performance.