Dynamic rate-selection for extending the lifetime of energy-constrained networks

Wireless networks have a constraint on their functional lifetime. This is due to the limited energy capacity of batteries powering the wireless nodes. For extending the lifetime of such battery-operated networks, we present a scheme for dynamically selecting the transmission rate for each node in the network. The transmission rate is based on the available energy budget in each node´s battery. The goal is to increase the network capability of delivering more packets. The rate selection for each node is subject to satisfying a QoS timing constraint on the packet delivery time. Through adaptively varying each node´s rate, we extended the lifetime 10 times on average more transmitting at a maximum rate and delivered on average 7.5 times more data packets. When compared with a scheme that transmits data at a lower rates independent of the battery levels, our scheme delivers up to 12% more packets for the same available total energy.