Underwater Acoustic Network Protocol based on Directed Graph: A self-organization method of underwater acoustic network with asymmetric communication links

Abstract

In an underwater acoustic network, the position of each underwater node is relatively fixed after it is deployed. Commonly, it is not easy to obtain auxiliary information before the network is established, such as accurate geographical position, environmental characteristics, and topological structure. The problem of asymmetry between communication uplink and downlink among nodes occurs due to the differences in transmission source level, transmission directivity, background noise, and propagation conditions of different nodes. To solve this problem, a self-organization method based on directed graph of the underwater acoustic network is proposed. In this proposed method, an adjacency matrix is established by adding the "neighbor discovery" phase before a round of simple flooding-based broadcasts and "inquire-reply" phase after that. The routing table is calculated based on the adjacency matrix using the classical shortest route algorithm to quickly complete the self-organization of the network with asymmetric communication links.