On the Achievable Forwarding Capacity of an Infinite Wireless Network

摘要

We consider the problem of finding the maximum directed packet flow that can be sustained in an infinite wireless mul-tihop network. This ability of the network to relay traffic is called the forwarding capacity, and the problem appears when the spatial scales corresponding to the end-to-end paths (routing) and the neighboring nodes (forwarding) are strongly separated in a massively dense network. We assume a Boolean interference model. The infinite network is approximated with a finite but large network where the node locations form a spatial Poisson process. We study two constructive approaches to tighten the lower bound for the forwarding capacity by a significant amount. In path scheduling the packets traverse the network using predefined paths that do not interfere with each other, and coordination is thus required only between the nodes of a path. In greedy maximum weight scheduling, the transmissions are scheduled greedily according to queue-length based weights of the links. In addition to a fixed transmission radius, we consider greedy maximum weight scheduling with a transmission radius adjustable up to a given maximum. We are able to produce numerical results that characterize the achievable forwarding capacity under global coordination of the transmissions, providing, e.g., concrete points of reference for practical distributed implementations.