Node Discovery Protocol and Localization for Distributed Underwater Acoustic Networks

The problem of underwater positioning is increasingly crucial due to the emerging importance of sub-sea activities. At the surface, positioning problems have been resolved by extended use of GPS, which is straightforward and effective. Unfortunately, GPS in the sub-sea environment is impossible and positioning requires special systems. These are all currently based on use of acoustic techniques, where positions are determined by triangulation using acoustic sources, whose relative location is known. One of the major challenges in the underwater acoustic networks (UANs) area of research is the development of a networking protocol that can manage dynamic sub-sea networking. In this paper we propose a protocol that is capable of node discovery and relative location. The methods and strategies of node discovery starts with one seed node (primary seed) in a known position. The primary seed node is capable of determining the relative positions of neighbouring nodes, and eventually other nodes in the network, without using eternal data. The self initialization involves some remote nodes becoming seed nodes for further discovery cycles. We compare and evaluate variations in the algorithms for random topology networks.