Software Defined Sensing

After a decade of extensive research on application-specific WSNs, the recent development of information and communication technologies makes it practical to realize SDSNs, which are able to adapt to various application requirements and to fully explore the resources of WSNs. A sensor node in SDSN is able to conduct multiple tasks with different sensing targets simultaneously. A given sensing task usually involves multiple sensors to achieve a certain quality-of-sensing, e.g., coverage ratio. It is significant to design an energy-efficient sensor scheduling and management strategy with guaranteed quality-of-sensing for all tasks. To this end, three issues shall be considered: (1) the subset of sensor nodes that shall be activated, i.e., sensor activation, (2) the task that each sensor node shall be assigned, i.e., task mapping, and (3) the sampling rate on a sensor for a target, i.e., sensing scheduling. In this chapter, they are jointly considered and formulated as a mixed-integer with quadratic constraints programming (MIQP) problem, which is then reformulated into a mixed-integer linear programming (MILP) formulation with low computation complexity via linearization. To deal with dynamic events such as sensor node participation and departure, during SDSN operations, an efficient online algorithm using local optimization is developed. Simulation results show that the proposed online algorithm approaches the globally optimized network energy efficiency with much lower rescheduling time and control overhead.