Publication Detail

Node Discovery Protocol for Ad Hoc Underwater Acoustic Networks

Ashish P. Patil
43 pp.
MITSG 10-26
$55.00 DOM / $75.00 INT

In a newly deployed ad hoc network there is no structure; this means that the nodes do not have any knowledge of their neighbors’ IDs and locations. Thus node discovery is the first step in building the network. The node discovery protocol enables the nodes to find their neighbors and thus brings structure into the network. Simultaneously, the nodes discover
the minimum power level required to reach a particular neighbor. Conservation of energy is an important aspect in the design of underwater acoustic networks since the power is battery supplied. Power control is thus used at each node. The key features of the protocol are the simplicity of implementation and the efficient use of power. The protocol that we
are proposing proceeds in cycles, with each cycle led by a single node, called a cycle leader. During the discovery phase each new leader starts at the minimal power level, increasing it only when necessary. Also a sign-up sheet is circulated among the leaders. The discovery ends when the sign-up sheet is full (or when all nodes have reached the maximum power level, but some are missing because they are out of reach or have failed). Upon completion, each node has built a list of its contacts which include, at a minimum, the nearest neighbor. The regular network operation commences after the completion of the discovery procedure. We evaluate the performance of the protocol for the no fading (idle case) and under fading. For the ideal case the protocol gives desired results whereas the effect of fading is to degrade the system performance. In order to combat the effect of fading we suggest some tweaks to our protocol and subsequently show how they help to improve the performance.

type: Full theses / dissertations

Parent Project

Project No.: 2007-R/RT-2/RCM-21
Title: Acoustic Communication Networks for Distributed Autonomous Underwater Platforms

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