Popis: |
It has been a challenging problem to support target coverage with QoS requirements in wireless sensor networks, because we need to consider both energy constraint and so-called target Q-coverage requirement, i.e. different targets may require different sensing quality in terms of the number of transducers, data sampling rate, etc. First we prove that this problem is NP- complete, then we formulate the optimization using Linear Programming techniques, however, directly solving this optimization seems desperately complex due to the combinatorial complexity. Thus a column generation based approach is developed to solve this problem by decomposing the original problem into a master problem as well as a corresponding sub problem and solves them iteratively. Numerical results are given to verify our approach and gain some insights into the performance aspects in designing such surveillance systems. |