Abstract-We formulate the problem of delay constrained energy-efficient broadcast in cooperative multihop wireless net works. We show that this important problem is not only NP complete, but also o(log(n)) inapproximable. We derive approx imation results and an analytical lower-bound for this problem. We break this NP hard problem into three parts: ordering, scheduling and power control. We show that when the ordering is given, the joint scheduling and power-control problem can be solved in polynomial time by a novel algorithm that combines dynamic programming and linear programming to yield the min imum energy broadcast for a given delay constraint. We further show empirically that this algorithm used in conjunction with an ordering derived heuristically using the Dijkstra's shortest path algorithm yields near-optimal performance in typical settings. We use our algorithm to study numerically the trade-otT between delay and power-efficiency in cooperative broadcast and compare the performance of our cooperative algorithm with a smart non cooperative algorithm.
In REF , Baghaie and Krishnamachari prove that the problem of minimizing the energy consumption while meeting a desired latency constraint is not only NP-hard but also o(log n) inapproximable.
Delay constrained minimum energy broadcast in cooperative wireless networks
2011 Proceedings IEEE INFOCOM
2011 Proceedings IEEE INFOCOM
Computer Science