Quorum-based neighbor discovery in self-organized cognitive MANET

In cognitive radio ad hoc networks each node scans and finds its own available frequency channel set for transmitting or receiving signals. Since nodes may be tuned on different frequencies and the nodes available channel sets are not the same, neighbor discovery becomes more challenging in self-organized mobile ad hoc networks with cognitive radios. This paper proposes a quorum-based neighbor discovery algorithm for asynchronous networks by taking advantage of quorum systems. The novelty of this approach is using quorum systems for neighbor discovery in neighbor discovery procedure. The proposed algorithm presents outstanding performance in both synchronous and asynchronous networks. In this approach due to the random back off time before each transmission and by using quorum-based algorithm the discovery performance is almost independent of the number of nodes in the network. The quorum system as the key idea in this approach, guarantees at least a common active interval for any two frequency channels. This approach can be classified as handshake-based deterministic neighbor discovery algorithm for cognitive radio networks. In this paper, the correctness of quorum-based cognitive discovery technique has been proved and its performance is evaluated with a number of simulations for various synchronous and asynchronous networks.