Spatial Reuse through Dynamic Power and Routing Control in Common-Channel Random-Access Packet Radio Networks

Abstract

Topologies of common-channel packet radio networks (PRNETs) are difficult to optimize because some of the links between multiple pairs of packet radio units are not independent. Previous analysis has shown that designing the topology to provide spatial reuse of the common-channel will improve the network throughput and delay performance in general. Unfortunately, the complexity of the link interactions has impeded the design of protocols that can be implemented in operational networks. This dissertation discusses how to optimize the topologies of common-channel random-acess PRNETs through dynamic power control at the link layer and routing at the network layer. Methods of implementing dynamic power control at the link layer on an individual packet-by-packet transmission basis are presented. These methods should be implementable at the link layer of any packet radio with dynamic per-packet power control capability. A new routing protocol, called Least Interference Routing (LIR), is defined which is designed specifically to operate in common-channel random-access PRNETs. The goal of LIR is to minimize the destructive interference caused along each route within the network, thus improving the spatial reuse of the common-channel. The LIR protocol calculates the potential destructive interference along each link, creates the network routing tables that minimize the potential destructive interference along an entire route, and specifies the per-packet transmission power. The implementation flexibility of each of these operations allows LIR to be implemented in a variety of radios and radio networks. Myopic one-hop and network multiple-hop simulations indicate that dynamic power control and/or LIR improve end-to-end PRNET performance over no power control or other routing strategies, such as minimum hop routing.