3-Way multi-carrier asynchronous neighbor discovery algorithm using directional antennas

Neighbor discovery is a crucial initial step to establish connections among the nodes in Ad hoc network. Multi-carrier modulation possesses superiority on parallel processing, which is widely used in neighbor discovery researches with directional antennas. However, when the node scale becomes larger, the existing algorithms of 1-way and 2-way handshake may increase the collision probability, leading to a high discovery latency. Therefore, a novel multi-carrier asynchronous neighbor discovery algorithm named 3-way MC-NDA has been proposed in this paper based on the feedback acknowledgement mechanism to minimize discovery time. The 3-way MC-NDA improves the interaction rules of handshake process by adding ack-packets substate to avoid the data delivery failure caused by unnecessary collisions and shorten the discovery latency. Simulation results denote that the proposed 3-way MC-NDA can decrease the expected neighbor discovery time by 95.6% than 1-way's and 98.3% than 2-way's on average. Furthermore, it can overcome the sensitivity to the large node density in traditional 2-way algorithm.