Capacity of Ad Hoc wireless networks

Jinyang Li, Charles Blake, Douglas S.J. De Couto, Hu Imm Lee, Robert Morris
2001 Proceedings of the 7th annual international conference on Mobile computing and networking - MobiCom '01  
Early simulation experience with wireless ad hoc networks suggests that their capacity can be surprisingly low, due to the requirement that nodes forward each others' packets. The achievable capacity depends on network size, traffic patterns, and detailed local radio interactions. This paper examines these factors alone and in combination, using simulation and analysis from first principles. Our results include both specific constants and general scaling relationships helpful in understanding
more » ... e limitations of wireless ad hoc networks. We examine interactions of the 802.11 MAC and ad hoc forwarding and the effect on capacity for several simple configurations and traffic patterns. While 802.11 discovers reasonably good schedules, we nonetheless observe capacities markedly less than optimal for very simple chain and lattice networks with very regular traffic patterns. We validate some simulation results with experiments. We also show that the traffic pattern determines whether an ad hoc network's per node capacity will scale to large networks. In particular, we show that for total capacity to scale up with network size the average distance between source and destination nodes must remain small as the network grows. Non-local traffic patterns in which this average distance grows with the network size result in a rapid decrease of per node capacity. Thus the question "Are large ad hoc networks feasible?" reduces to a question about the likely locality of communication in such networks. ¥ ¤ n£ . With this assumption, the total end-toend capacity is roughly O¢ n¦ ¤ n£ , and the end-to-end throughput available to each node is O §
doi:10.1145/381677.381684 dblp:conf/mobicom/LiBCLM01 fatcat:wuo5khekgbgkti3j6s4vfnyvqm