Neighbor Discovery in Multi-Receiver Cognitive Radio Networks∗

A cognitive radio (CR) node is a radio device capable of operating (transmitting and receiving) over multiple channels. As a result, a network consisting of one or more cognitive radio nodes can adapt to varying channel availability in its geographical region by dynamically changing the channel (or channels) that nodes use for communication. We investigate the problem of neighbor discovery in a network consisting of one or more cognitive radio nodes when nodes have multiple receivers but only a single transmitter. Neighbor discovery, in turn, can be used to solve other important communication problems such as broadcasting and gossiping in an efficient manner. We present a TDMA-based deterministic distributed algorithm for neighbor discovery whose time-complexity is M ⌈ N r ⌉ + O(max(M, N) log r), where M is the maximum number of channels on which a node can operate, N denotes the size of the space used to assigned identifiers to nodes, r is the number of receivers at a node (with 1 ≤ r ≤ min(M, N)).