期刊名称：International Journal of Computer Networks (IJCN)
电子版ISSN：1985-4129
出版年度：2014
卷号：6
期号：3
页码：50-65
出版社：Computer Science Journals
摘要：In IEEE 802.16j relay networks, wireless communications are carried out based on TDMA where the wireless network resources are divided into multiple time slots and they are assigned to wireless links between relay nodes as transmission opportunities. The network performance is improved by decreasing the total number of different time slots assigned to all links in a single scheduling cycle, because it brings the increase in the transmission opportunities of the links per unit time. Although it can be achieved when multiple links utilize the same time slot, the capacity of such links is degraded due to the radio interference. On the other hand, since all links in the network need to have enough time slots to accommodate their traffic load, degrading the link capacity may increase the total number of different time slots in the scheduling cycle. Therefore, we should determine the time slot assignment by considering the above-mentioned tradeoff relationship. In this paper, we propose heuristic algorithms for time slot assignment problem in IEEE 802.16j relay networks, and evaluate them through extensive simulation experiments. Two algorithms based on different heuristic are introduced. One algorithm assigns a set of time slots to links by a greedy approach. The other algorithm determines a set of links that use a time slot by a brute-force search for maximizing the total link capacity. Performance evaluation results exhibit that the proposed algorithms reduces around 34% and 39% of the total time slots compared with the case where no link utilizes the same time slot, respectively. Meanwhile, they also show that calculation time of the latter algorithm is longer than that of the former algorithm to reduce the total time slots. Thus, we show that there is a tradeoff between performance and calculation time.
关键词：IEEE 802.16j; Radio Interference; TDMA; Time Slot Assignment; Heuristic Algorithm.
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