Power-delay trade-off in a many-to-many wireless access

Given a set of communication links sharing a channel, delay for delivery of a given amount of backlogged data can be traded off against average power consumption, for a fixed transmission link requirement. The main result of this work is the identification of general bounds for the average power needed to deliver a given backlog within a delay constraint and their application to compare orthogonal (TDMA) and concurrent (CDMA) multiple access. Numerical examples for a collection of links belonging to an ad-hoc network are discussed. It turns out that non-orthogonal CDMA can be the only viable choice for strict (yet feasible) delay constraints, the price to be paid being a larger energy consumption. Also, CDMA offers better power-delay trade-off for low interference as well as high path loss channel scenarios. (C) 2008 Elsevier B.V. All rights reserved.