In wireless networks, transmitter power control can play an important role in improving a number of key performance parameters, including energy usage, network capacity, and network reliability. As wireless ad hoc networks become more prevalent, it is critical that power control algorithms operate in a distributed fashion, since centralized network controllers are rarely available for such systems. This project explores the evolution of distributed power control (DPC) algorithms over the last 15 years through a literature review and simulations, and it examines future research directions in this field. In particular, we consider the emergence of backlog-aware algorithms for DPC, which exploit the tradeoff between power and delay in the network to induce cooperation between links. The simulations that were conducted provide a comprehensive platform for the evaluation of such algorithms, which was largely lacking in the literature.
Several interesting aspects of backlog-aware algorithms are highlighted by our simulation results. The most powerful result is a validation of the intuition that backlog-aware algorithms, by relying on teamwork between links, can provide significant performance gains as compared to competitive algorithms such as the seminal Foschini-Miljanic approach. These gains are particularly large when the network is under duress - either when the load is too great for the links to clear their queues, or when the cross-link interference becomes large. In addition to presenting and discussing the simulation results, this work also describes the next steps in this line of research, including extending the currently-used simulations, overcoming difficulties in the comparison of different algorithms, mathematically proving the observed structural properties of backlog-aware DPC techniques, and designing better algorithms for future systems.