Interference aware relay station location planning for IEEE 802.16j mobile multi-hop relay network

Abstract

In this paper, an interference aware algorithm for multi-cell Relay Station (RS) location planning problem is proposed in order to investigate the capacity gains possible using transparent mode 802.16j. The study focuses on the problem of determining the best choice of locations for RS from a given set of candidate sites - Base Station (BS) and Subscriber Station (SS) locations are assumed given. The proposed algorithm evaluates each RS based on the channel conditions of the links between the RS and its surrounding Subscriber Stations(SS) and the throughput gain it could deliver, taking into account co-channel interference. The performance statistics were collected over a large amount of experiments with many different configurations, including Base Station(BS) antenna types, number of candidate RS sites, RS transmitting power, with/without spatial reuse, etc. The results can be divided into two sections. Firstly, the algorithm was tested for optimality and scalability and was shown to perform well compared to classical Integer Programming solution techniques. Secondly, the results generated by the algorithm when applied to different scenarios were analyzed. Results show that using spatial reuse could achieve a much higher throughput gain, 3-5 time, then without using spatial reuse, although sectorised BS antenna limits the separation of co-channel RSs in a sector. The results demonstrate the characteristics of the trade-off between number of RSs and throughput gain for different configurations.