Hierarchical MAC protocol with multi-channel allocation for enhancing IEEE 802.11ah relay networks

With the introduction of IEEE 802.11ah wireless LAN standard, Internet of Things (IoT) is expected to develop more rapidly. IEEE 802.11ah introduces a relay node to extend wireless range with high energy efficiency for a large number of station nodes. This paper presents an efficient method of allocating multiple channels to multiple relay nodes of IEEE 802.11ah network. We propose a formulation for an optimal calculation of mutual exclusive segment angle using wireless link parameters. We present a hierarchical Medium Access Control (MAC) mechanism for efficient management and deployment of relays. It increases wireless range of network, improves the overall throughput by minimizing interference, and effectively conserves station node´s energy. We implemented IEEE 802.11ah relay protocol based the hierarchical MAC using ns-3 simulator. Experimental results show that the proposed scheme provides substantial improvement in throughput performance.