Abstract：Unreliable link in wireless sensor networks ( WSNs) brings more energy consumption and transmission delay because of multiple retransmission. In order to improve the network lifetime of low-duty-cycle WSNs, a novel energy-efficient routing algorithm ( EERA) is proposed. A more reliable link and low transmission delay candidate node set is selected from a node's neighbor nodes which meet thresholds for link quality and link transmission delay, and the relay node can be finally chosen in these candidate nodes. Data were delivered from the source to the sink in descending order of hop number, and the route to the sink achieved the minimum energy consumption. Simulation results show that EERA can improve the packets' delivery ratio, and efficiently reduce energy consumption of the networks.

Keyword：link quality;energy-efficient;wireless sensor networks;routing protocol;