A Novel AID Shuffle Mechanism for RAW Slot Assignment in IEEE 802.11ah Networks

To implement the new restricted access window (RAW) medium access control mechanism in IEEE 802.11ah, stations (STAs) must be assigned to RAW slots based on their association IDs (AIDs). In this paper, we first identify the fixed subgroup problem with the current round-robin slot assignment. To address it, a novel AID shuffle mechanism is proposed for each STA to distributedly find a different and distinct temporary AID in each RAW. Each STA then reuses the round-robin slot assignment with its temporary AID. As a result, the set of STAs assigned to each subgroup/slot are randomized, yet with the same subgroup size. Simulation results show that the transmission fairness problem with the original round-robin assignment is solved and the system throughput is also improved.