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Demand for last-mile broadband access networks has grown significantly due to the rapid growth in demand for Internet access and multimedia services. While Cable and xDSL have filled the demand for residential and small businesses to some extent, having a broadband wireless access (BWA) such as systems based on the IEEE 802.16 standard will substantially increase the means of meeting such demand. The advantages of BWA systems include rapid deployment, high scalability and lower maintenance and upgrade costs, while being competitive with wired systems in terms of data rates.
However, having only a point-to-multipoint network where all the nodes are directly connected to a central node is not always physically feasible, nor does it offer robustness in the face of adverse physical conditions for communications.
With the approval of the mesh mode extension to the IEEE 802.16 standard, fast and reliable wireless connectivity with a range many times in excess of the range of the physical layer has become a reality. The optional mesh mode extension not only increases the coverage range, but also eliminates the need for the requirement of having line-of-sight in order to communicate.
We propose a novel two-phase link scheduling algorithm for the IEEE 802.16 Mesh Mode that will provide optimal channel throughput and fair channel access among the different subscriber stations. The algorithm is for the centralized scheduling (MSH-CSCH) standard.
Definitions and terminology:
The base station (BS) is the central node that has a direct backhaul link to the external WAN. These nodes not only provide access to a wider network but also control the entire IEEE 802.16 network including network entry by other nodes and access to the wireless channel. There should only be one base station per network. All other nodes are called subscriber stations (SS).
A neighbor node is defined as a node that is exactly 1-hop away from the node of interest. A collection of neighbor nodes is called a neighborhood. The extended neighborhood includes all nodes within 2 or 3 hops (configurable parameter).
A sponsor node is defined as a neighboring node that relays both control and data transmissions to and from the base station. These nodes are assumed to be closer to the base station, and thus have more favorable channel conditions.