Activating anonymous ad hoc radio networks

We consider the task of activating an anonymous ad hoc radio network from a single source, by a deterministic algorithm. In the beginning only the source is active and has to activate other nodes by disseminating messages throughout the network. Nodes of the network do not know its topology and they do not have distinct labels. In such networks some nodes are impossible to reach. A node in a network is accessible if it can be activated by some (possibly network-dependent) deterministic algorithm. We show that the problem of recognizing whether a given node of an anonymous radio network is accessible, can be solved in polynomial time for the synchronous scenario. A deterministic wake-up algorithm for ad hoc networks is universal if it activates all accessible nodes in all networks. We study the question of the existence of such a universal activating algorithm. For synchronous communication we design a universal activating algorithm, and for asynchronous communication we show that no such algorithm exists.