Scheduling in multihop WiMAX networks

IEEE 802.16, popularly known as WiMAX, is at the forefront of the technology drive because of the growing demand for high-speed wireless broadband networks. Multihop WiMAX networks are particularly useful as they increase the coverage area without the need to deploy expensive base stations. There are two kinds of multihop WiMAX networks - WiMAX mesh and Mobile Multihop Relay Networks. Scheduling is very important in both of these multihop WiMAX networks. The links have to be scheduled in such a way so that they do not interfere with each other while maximizing the throughput of the networks. As WiMAX networks are geared towards broadband applications, any scheduling scheme should accomodate the rate, latency and jitter requirements of the applications. This article provides an insight to the scheduling framework presented in the IEEE 802.16 standard. It also presents a few representative research proposals for centralized scheduling in WiMAX networks. We discuss some of the research issues and challenges that need to be addressed for multihop WiMAX networks to realize their full potential.