Joint Node and Link Assignment in an STDMA Network

Abstract

Spatial re-use TDMA (STDMA) is a medium access control (MAC) protocol which allows multiple transmitter-receiver pairs to communicate simultaneously, as long as they do not interfere too much with each other. Node and link assignment strategies for spatial re-use TDMA networks have previously been studied independently. The metric chosen in these studies is the uniform capacity, the minimum rate at which any node can communicate with any other node in the network. It has been shown that for large frame lengths, node assignment leads to lower spatial re-use than link assignment, resulting in lower uniform capacity than link assignment. In this paper, we first explore the behaviour of node and link assignment at small frame lengths. We show that node assignment achieves non-zero throughput values at lower frame lengths than link assignment, and that it outperforms link assignment at small frame lengths. This motivates the need for an assignment strategy that performs well for all values of the frame length. We propose a joint node-link assignment strategy and show that it performs as well as node assignment at small frame lengths and as well as link assignment at large frame lengths, while exceeding the performance of both node and link assignment at intermediate frame lengths.