An FEC-based Reliable Data Transport Protocol for Underwater Sensor Networks
Peng Xie and Jun-Hong Cui
xp@engr.uconn.edu, jcui@cse.uconn.edu
Computer Science and Engineering Department
University of Connecticut, Storrs, CT 06269-2155
Abstract—In this paper, we investigate the reliable data
transport problem in underwater sensor networks. Underwater
sensor networks are significantly different from terrestrial
sensor networks in two aspects: acoustic channels are used for
communication and most sensor nodes are mobile due to water
current. These distinctions feature underwater sensor networks
with low bandwidth capacity, large propagation delay, high error
probability, half-duplex channels, and highly dynamic topology,
which pose many new challenges for reliable data transport
in underwater sensor networks. In this paper, we propose a
protocol, called segmented data reliable transport (SDRT), to
achieve reliable data transfer in underwater sensor networks.
SDRT is essentially a hybrid approach of ARQ and FEC.
It adopts efficient erasure codes (so-called SVT codes in this
paper), transferring encoded packets block by block and hop
by hop. Compared with other existing reliable data transport
approaches for underwater networks, SDRT can reduce the
total number of transmitted packets, improve channel utilization,
and simplify protocol management. In addition, we develop a
mathematic model to estimate the expected number of packets
actually needed. Based on this model, we can set the block size
appropriately for SDRT, as helps to address the node mobility
issue. We conduct simulations to evaluate our model and SDRT.
The results show that our model can closely predict the number
of packets actually needed, and SDRT is energy efficient and can
achieve high channel utilization.