The capacity and energy efficiency of wireless ad hoc networks with multi-packet reception

Abstract

We address the cost incurred in increasing the transport capacity of wireless ad hoc networks over what can be attained when sources and destinations communicate over multi-hop paths and nodes can transmit or receive at most one packet at a time. We define the energy efficiency ·(n) as the bit-meters of information transferred in the network for each unit energy. We compute the energy efficiency of many different techniques aimed at increasing the capacity of wireless networks and show that, in order to achieve higher transport capacity, a lower energy efficiency must be attained. Using the physical model, we compute the throughput capacity of random wireless ad hoc networks in which nodes are endowed with multi-packet reception (MPR) capabilities. We show that λ(n)= Θ (R(n))(1-2/α) / n1/α) bits per second constitutes a tight upper and lower bound for the throughput of random wireless ad hoc networks, where α>2 is the path loss parameter in the physical model, n is the total number of nodes in the network, and R(n) is the MPR receiver range. In doing so, we close the gap between the lower and upper bounds for the throughput capacity of wireless networks in the physical model. Compared to the original result derived for plain routing by Gupta and Kumar, MPR achieves a capacity gain of at least Θ((log n)α-2/2α) when RR(n)= Θ(√log n/n).