Asynchronous computing and communication architecture toward energy efficient wireless sensor networks

An asynchronous architecture, consisting of asynchronous sampling strategies and asynchronous MAC protocols, is proposed to achieve a better tradeoff between energy efficiency and application´s performance in wireless sensor networks (WSNs). Motivated by the data correlation in dense WSNs, asynchronous sampling strategies assign time shifts to nodes´ sampling moments to obtain asynchronous sensory data, which is proved to contain more information than the synchronous sensory data at the same sampling rate. With the help of asynchronous sampling, the network could reduce the sampling rate without sacrificing application´s performance. To further conserve energy, asynchronous MAC protocols enabled by passive RFID tag are presented to avoid idle listening and reduce end-to-end delay through pipelining and multi-path routing principle. By forming an asynchronous architecture of WSNs, the approach is able to achieve energy efficiency while guaranteeing not only the information obtained from the sensory data but also the message delay to the sink.