Date Added: May 2012
Due to requirements in different applications, sensors with various capacities are deployed. Data routing in such Heterogeneous Wireless Sensor Networks (HWSNs) poses challenges. First, the heterogeneous features create asymmetric links in the communication graphs which are not dealt with by conventional routing algorithms using undirected graphs. Second, it is important to provide an assured delivery rate for mission critical applications since sensors communicate with each other through lossy asymmetric links. In this paper, the authors propose LayHet: a layer-based routing protocol for HWSNs, which takes advantage of the asymmetric links to deliver messages to the sink with an assured delivery rate.