Performance analysis of transparent relays in 802.16j MMR networks

Abstract — A simulation study of the performance of transparent mode relay-based 802.16j systems is described. The study focuses on the gain in throughput that is possible in omnidirectional relay systems and increases in signalling requirements that arise due to the multihop network architecture. The study finds that the introduction of transparent mode relays cannot deliver improved throughput for a substantial part of the coverage area of a Base Station (BS) – only approximately half of the total area covered by the BS can benefit from throughput enhancement. Further, the study shows that 802.16j based systems require significant signalling overhead, with almost twice that of 802.16e in the cases studied. Finally, the study demonstrates that in a topology with users uniformly distributed within the BS cell coverage, the maximum throughput increase on the downlink that can be achieved is relatively low. Much further work is necessary to realise useful gains from these systems. Keywords-802.16j MMR, transparent multihop relay, performance, omnidirectional antenna. I