Opportunistic Scheduling in IEEE 802.11n WLAN

In wireless local area network (WLAN) environment with independent user fading, at least one user is likely to undergo very good channel state at any time, and this is called multiuser diversity. For high system performance, a transmission scheduler at the LLC layer is required to exploit this multi-user diversity by opportunistically selecting a feasible user with a good channel, and it is referred to as Opportunistic Scheduling (OS). In this paper, we proposed an OS scheme which is adaptive to the 802.11n WLAN. Different with existing OS schemes, it takes into account the two distinct characteristics of 802.11n, which are the frame aggregation and the quality of service (QoS) requirements according to the access categories (ACs). Through the simulation results, we prove that the proposed scheme not only improves the total system throughput, but it also preserves fairness and the QoS requirements corresponding to the ACs in the 802.11n WLAN. Key-Words: 802.11n WLAN, Opportunistic Scheduling, System Throughput, Fairness, QoS