Abstract:
Underwater acoustic sensor networks(UWASNs) is an emerging technology, comprising of
sensor nodes and unattended automated vehicles (AUVs), all working in a collaboration to
sense various phenomenon, process digital information, store processed data and
communicate among each other and base stations. UWASNs have the capability and potential
of supporting large set of applications ranging from oceanic geographical surveys to tactical
surveillance. Underwater Acoustic propagation is characterized by high and variable delays,
fading effect, Doppler spread and multi path which in turn lead to a limited bandwidth and
high error rates. At the same time, battery life of the sensor nodes and their data storage
capacity is limited. So there is a need to find a suitable routing protocol that takes all these
limitations into consideration and makes communication in underwater networks viable. In
this paper we focus on existing mobile ad-hoc routing protocols which are widely accepted
and have been tested across the globe. This is the first attempt to analyze the performance of
these protocols in underwater acoustic networks environment. The first challenge is to come
up with a reliable simulation environment for underwater networks in ns-2. Currently, ns-2
does not support simulation for underwater networks. We extended ns-2 for underwater
networks by adding underwater propagation, network interface (data link layer) and
underwater physical models. After having a working underwater networks simulation model,
we then proceeded with our study. We used performance metrics like packet delivery ratio,
average end-to-end delay, throughput, routing overhead and energy consumption of the
sensor nodes. AODV, DSDV, DSR and OLSR are compared for their performance at
different traffic conditions, number of nodes and depths. By analyzing our simulation results,
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we found that AODV is recommended for denser underwater networks but with less traffic.
DSDV is suitable for higher traffic conditions with optimal number of nodes.
