Energy-Efficient Optimization for Concurrent Compositions of WSN Services

Sharing the infrastructure of wireless sensor networks (WSNs) for achieving concurrent requests becomes a trend nowadays, where a relatively complex request should be satisfied through aggregating complementary functionalities provided by contiguous sensor nodes contained in a certain network region. To address this challenge, this paper proposes a multi-requests cooperative-integrating mechanism leveraging service-oriented WSNs. Specifically, a sensor node is encapsulated with one or multiple WSN services, which capture various functionalities provided by this sensor node. These WSN services can be categorized into service classes, where their functionalities are the main concern. Candidate service class chains are generated independently with respect to concurrent requests represented in plain text. The selection of candidate WSN services for the instantiation of certain service classes can be reduced to a multi-objective and multi-constraints optimization problem, where the spatial and temporal-constraints, and energy efficiency of the network, are the factors to be considered. This combinational optimization problem is solved through adopting heuristic algorithms. Experimental results show that this technique improves the shareability of WSN services among concurrent requests, and reduces the energy consumption of the network significantly, especially when the spatial, temporal, and functional overlap between concurrent requests is relatively large.