Broadcasting in conflict-aware multi-channel networks

Abstract

The broadcasting problem asks for the fastest way of transmitting a message to all nodes of a communication network. We consider the problem in conflict-aware multi-channel networks. These networks can be modeled as undirected graphs in which each edge is labeled with a set of available channels to transmit data between its endpoints. Each node can send and receive data through any channel on its incident edges, with the restriction that it cannot successfully receive through a channel when multiple neighbors send data via that channel simultaneously. We present efficient algorithms as well as hardness results for the broadcasting problem on various network topologies. We propose polynomial time algorithms for optimal broadcasting in grids, and also for trees when there is only one channel on each edge. Nevertheless, we show that the problem is NP-hard for trees in general, as well as for complete graphs. In addition, we consider balanced complete graphs and propose a policy for assigning channels to these graphs. This policy, together with its embedded broadcasting schemes, result in fault-tolerant networks which have optimal broadcasting time. © 2013 Springer-Verlag.