Distributed power control (DPC) based energy efficient protocols for wireless networks

Energy efficiency is an important issue for wireless networks since it extends the lifetime of a wireless network and improves quality of service (QoS). Therefore, the overall objective of this dissertation is to develop energy efficient schemes and medium access control (MAC) protocols for wireless networks in the presence of fading channels while satisfying network constraints and user defined QoS requirements.;First, a novel distributed power control (DPC) scheme is introduced for cellular networks and subsequently extended to wireless ad hoc and sensor networks by using a new channel prediction scheme. DPC minimizes energy consumption by predicting the least transmission power required to maintain a desired Signal-to-Noise-Ratio (SNR). Next, innovative predictive congestion control schemes for wireless ad hoc and sensor networks are presented. They exercise flow control to overcome buffer overflows thus reducing retransmissions and minimizing excess energy consumption. The ad hoc version of the protocol relies on rate adaptation of packets by using multiple modulation schemes. Tradeoff between higher throughput and lower energy consumption is addressed using dynamic programming (DP) approach. In the case of sensor networks, nodes are limited to a single modulation rate. Hence, the proposed protocol relies on the adaptive selection of back-off intervals in order to prevent buffer overflows and satisfy a predefined QoS.;The stability and convergence analysis of the proposed algorithms are guaranteed analytically and through extensive simulation studies by using the ns-2 simulator. Performance comparison of the proposed schemes with the ones available in the literature is also reported, with the proposed DPC scheme transmitting up to 3 times more data per joule than the 802.11, and the congestion control scheme adding further 15% to the efficiency over the DPC.