Communication-centric energy conservation for multi-hop wireless networks.

摘要

Energy conservation is one of the greatest challenges in multi-hop wireless networks due to the ever-increasing energy requirements of wireless devices and the slow advancement of battery technology. While significant energy savings can be obtained by incorporating energy efficiency into the design of network protocols, current research has focused on optimizing the energy use either for a given communication task or when the network is idle. However, an integrated approach is lacking. Therefore, we explore the limits of traditional stand-alone techniques and expose some commonly held myths about energy conservation in wireless multi-hop networks. The main goal of our research is to develop a unified design that enables energy-efficient network operation.;In the first part of the thesis, we explore the existence of an optimal operating point that minimizes energy while satisfying the communication requirements on the network. Our goal is to conserve energy by accounting for all sources of energy consumption: (1) energy consumed for communication and (2) energy consumed during idling. Essentially, this is an energy-efficient network design problem. Due to the complexity of the problem, we follow a divide-and-conquer approach, which first reduces energy consumed in idling and second the energy consumed in data communication. Essentially, this two-stage approach is the only feasible approach that meets the challenge of operating the network with low energy cost without degrading communication.;From our experiences with energy-efficient network design, we observed that: (1) idling energy should be the primary target for energy conservation, (2) any energy conservation solution cost prohibitive with increasing overhead, and (3) minimizing energy consumption does not necessarily improve network lifetime. Therefore, in the second part of the thesis, we formulate solutions to each of these problems. To reduce idling energy, we propose a bulk-communication protocol that achieves high energy savings from using a high-power radio for data communication and a low-power radio for network maintenance. To reduce control and data overhead, respectively, we present two protocols: (1) adaptive route recovery and (2) probability-based broadcast forwarding. Finally, to balance energy consumption in the network, we propose re-distributing traffic locally based on the remaining energy of nodes.