Greedy-Based Dynamic Channel Assignment in Clustered Multihop CDMA/TDMA Ad Hoc Networks

Ting-Chao HOU  Chien-Min WU  Ming-Chieh CHAN  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E87-A    No.7    pp.1720-1732
Publication Date: 2004/07/01
Online ISSN: 
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Multi-dimensional Mobile Information Networks)
Category: Multi-hop Wireless Networks

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A good channel assignment scheme in a multihop ad hoc network should not only guarantee successful data transmissions without collisions, but also enhance the channel spatial reuse to maximize the system throughput. It becomes very inefficient to use fixed channel assignment when the network size grows. Therefore, spatial reuse of channels become more important in a large multihop ad hoc network. In this paper, we consider an ad hoc network with an overlaid CDMA/TDMA structure. We divide each code into time slots to form the channels. A dynamic channel assignment (DCA) strategies called Greedy-Based DCA (GB-DCA) is proposed in a clustered wireless multihop ad hoc network. This DCA strategy is designed to make better use of available channels by taking advantage of the spatial reuse concept. In GB-DCA, the increase in spatial reuse is achieved by adding certain control overhead. We show that the bandwidth saving due to channel spatial reuse is higher than the additional bandwidth spent on the control overhead.