Interference-aware broadcast scheduling in wireless networks

In this paper, we study the INTERFERENCE-AWARE BROADCAST SCHEDULING problem, where all nodes in the Euclidean plane have a transmission range and an interference range equal to r and alpha r for alpha >= 1, respectively. Minimizing latency is known to be NP-Hard even when alpha = 1. The network radius D, the maximum graph distance from the source to any node, is also known to be a lower bound. We formulate the problem as integer programs (IP) and optimally solve moderate-size instances. We also propose six variations of heuristics, which require no pre-processing of inputs, based on the number of receivers gained by each additional simultaneous transmitting node. The experimental results show that the best heuristics give solutions that exceed the optimal solutions by only 13-20%. Further, an O(alpha D) schedule is proven to exist yielding an O(alpha) approximation algorithm. (C) 2010 Elsevier B.V. All rights reserved.