Energy-Efficient Communication in Multi-interface Wireless Networks

We study communication problems in wireless networks supporting multiple interfaces. In such networks, two nodes can communicate if they are close enough and share a common interface. The activation of each interface has a cost reflecting the energy consumed when a node uses this interface. We distinguish between the homogeneous and heterogeneous case, depending on whether all nodes have the same activation cost for each interface or not. For the homogeneous case, we present a (3/2+ϵ)-approximation algorithm for the problem of achieving connectivity with minimum activation cost, improving a previous bound of 2. For the heterogeneous case, we show that the connectivity problem is not approximable within a sublogarithmic factor in the number of nodes and present a logarithmic approximation algorithm for a more general problem that models group communication.