In combination with the energy efficient routing algorithm

the optimal sink position selection problem was studied

which aimed to minimize the overall network energy consumption.When the candidate set of sink positions is finite

the problem is shown to be an integer linear programming problem

when the candidate set is the whole space

the problem is shown to be a nonlinear programming problem.Due to the NP-completeness of the problems

several heuristic algorithms were designed accordingly.The proposed algorithms were examined by extensive simulation experiments

the results show that the performances of presented algorithms are close to the optimality.