Group-based contention in IEEE 802.11ah networks

IEEE 802.11ah which mainly aims for vast range sensor networks offers a transmission range of up to 1 km and about 8,000 nodes are handled by a single access point (AP). As a result, an 802.11ah network has more hidden pairs than conventional 802.11a/b/g/n/ac networks. Therefore, packets frequently collide resulting in network performance degradation. To solve the problem, the 802.11ah uses a group based contention. In this paper, we propose a guideline for choosing the number of groups. Through simulations, we also show how severely degraded the throughput performance is in a randomly deployed network.