Theoretical treatment of sink scheduling problem in wireless sensor networks

Sink Scheduling, in the form of scheduling multiple sinks among sink sites to leverage traffic burden, is an effective mechanism for the energy-efficiency of wireless sensor networks (WSNs). Due to the inherent difficulty (NP-hard in general), existing works on this topic mainly focus on heuristic/greedy algorithms and theoretic results remain unknown. In this paper, we fill in the research blank with two algorithms. The first one is based on the Column Generation (CG). It decomposes the original problem into two sub problems and solve them iteratively to approach the optimal solution. However, due to its high computational complexity, this algorithm is only suitable for small scale networks. The other one is a polynomial-time algorithm based on relaxation techniques to obtain an upperbound, which can serve as a performance benchmark for other algorithms on this problem. Through comprehensive simulations, we evaluate the efficiency of proposed algorithms.