In many military applications, such as networks whose nodes consist of either individual warriors or sensors, "energy-awareness" is of crucial importance. The goal of this basic research study is to develop a better understanding of such energy-related issues, and to develop novel approaches to networking that exploit the characteristics of wireless media. Most of our research has focused on broadcast (one-to-all) and multicast (one-to-several) communication. As a result of the differences between wireless and wired communication environments, conventional networking schemes (such as those adapted from wired networks) often do not perform well, and innovative approaches are needed.
A key feature of our approach is the use of "cross-layer" design, in which we exploit the properties of the wireless channel by jointly controlling RF transmission power (and hence communication range) along with the tree-construction process (which is normally considered independently). We have studied the two fundamental aspects of energy-aware performance, namely "energy-efficiency" and "operation under energy constraints." When energy efficiency is the goal, one would like to minimize the overall quantity of energy that is expended per unit of information. However, an energy-constrained system is different because a node dies when its battery becomes depleted. Thus, the objective in such a system is typically to maximize the network's lifetime and/or the amount of information that is delivered before the network dies.
We introduced the energy-aware broadcasting/multicasting problem to the research community, and have led its development. Our Broadcast Incremental Power (BIP) and Multicast Incremental Power (MIP) algorithms are the seminal research in this field, and have been referenced widely by others. They were originally developed for energy-efficient systems, but we developed a technique that greatly improves their performance in energy-constrained systems as well. This exceptionally productive study has produced five journal articles and 12 conference papers on various aspects of this problem in 2001 - 2002. One of our papers won the Best Unclassified Paper Award at the IEEE MILCOM 2000 conference.