Data-gathering wireless sensor networks: organization and capacity

In this paper we study the transport capacity of a data-gathering wireless sensor network under different communication organizations. In particular, we consider using a flat as well as a hierarchical/clustering architecture to realize many-to-one communications. The capacity of the network under this many-to-one data-gathering scenario is reduced compared to random one-to-one communication due to the unavoidable creation of a point of traffic concentration at the data collector/receiver. We introduce the overall throughput bound of lambda = W/n per node, where W is the transmission capacity, and show under what conditions it can be achieved and under what conditions it cannot. When those conditions are not met, we constructively show how lambda = Theta(W/n) is achieved with high probability as the number of sensors goes to infinity. We also show how the introduction of clustering can improve the throughput. We discuss the trade-offs between achieving capacity and energy consumption, how transport capacity might be affected by considering in-network processing and the implications this study has on the design of practical protocols for large-scale data-gathering wireless sensor networks. (C) 2003 Elsevier B.V. All rights reserved.