Abstract: There is a need to improve design of communications protocols in which two or more channels are provided and, optionally, in which collision avoidance is not available. An improved protocol is provided in which communications nodes pick a channel on which to transmit and collisions may occur where two nodes attempt to transmit on the same channel. The node currently occupying a channel is arranged to have a specified probability of holding onto that channel as compared to a newcomer. Other methods are described whereby a node is able to occupy more than one channel at the same time and whereby nodes each occupy approximately the same number of channels.

Abstract: In an unstructured overlay network, each node in the network periodically tests logical network links among neighboring nodes to determine whether the links should be reorganized. A Metropolis scheme is used to determine the probability with which the links are reorganized. This probability is computed based on the change in link costs and/or node degrees that would be effected by a proposed reorganization. The Metropolis scheme tends to maintain a consistency among the degrees of the nodes, thereby providing strong failure resilience.