2018 年 31 巻 7 号 p. 265-273
In wireless LANs (Local Area Networks), each station adapts its transmission rate according to the channel condition. Thus stations with different transmission rates coexist in a LAN. In such a LAN, the standard access method DCF (Distributed Coordination Function) causes the problem called performance anomaly, all the stations have the same throughput in spite of their transmission rates since the DCF provides equal access privileges among stations. In order to solve the problem, this paper proposes an access method which achieve transmission time fairness. Under the proposed method, the access point calculates the backoff periods for all stations. That could eliminate packet collisions and redundant idle periods. Via simulation, we show effectiveness of our method in comparison with the existing ones.