Underwater Acoustic Networks: Channel Models and Network Coding Based Lower Bound to Transmission Power for Multicast

Abstract

Abstract-The goal of this paper is two-fold. First, to establish a tractable model for the underwater acoustic channel useful for network optimization in terms of convexity. Second, to propose a network coding based lower bound for transmission power in underwater acoustic networks, and compare this bound to the performance of several network layer schemes. The underwater acoustic channel is characterized by a path loss that depends strongly on transmission distance and signal frequency. The exact relationship among power, transmission band, distance and capacity for the Gaussian noise scenario is a complicated one. We provide a closed-form approximate model for 1) transmission power and 2) optimal frequency band to use, as functions of distance and capacity. The model is obtained through numerical evaluation of analytical results that take into account physical models of acoustic propagation loss and ambient noise. Network coding is applied to determine a lower bound to transmission power for a multicast scenario, for a variety of multicast data rates and transmission distances of interest for practical systems, exploiting physical properties of the underwater acoustic channel. The results quantify the performance gap in transmission power between a variety of routing and network coding schemes and the network coding based lower bound. We illustrate results numerically for different network scenarios.

On the Effects of Frequency Scaling Over Capacity Scaling in Underwater Networks—Part I: Extended Network Model

“…Together with the studies in terrestrial radio networks, the interest in study of underwater networks has been growing, due to recent advances in acoustic communication technology [15][16][17][18]. In underwater acoustic communication systems, both bandwidth and received signal power are severely limited owing to the exponential (rather than polynomial) path-loss attenuation with long propagation distance and the frequency-dependent attenuation.…”

“…Hence, the system throughput is affected by not only the transmission distance but also the useful bandwidth. Based on these characteristics, network coding schemes [17,19,20] have been presented for underwater acoustic channels, while network coding showed better performance than MH routing in terms of reducing transmission power. MH networking has further been investigated in other simple but realistic network conditions that take into account the practical issues of coding and delay [21,22].…”

Information-theoretic limits of dense underwater networks

“…A recent result [4] has shown that an almost linear throughput in the network, i.e., Θ(n 1− ) for an arbitrarily small > 0, is achievable by using a hierarchical cooperation (HC) strategy. 2 Along with the studies in terrestrial radio networks, the interest in study of underwater networks has been growing [5], [6], due to recent advances in acoustic communication technology. In underwater acoustic communication systems, both bandwidth and received signal power can be severely limited owing to exponential (rather than polynomial) pathloss attenuation with propagation distance and frequencydependent attenuation.…”

Multi-hop routing is order-optimal in underwater extended networks

“…Along with the studies in terrestrial radio networks, the interest in study of underwater networks has been growing with recent advances in acoustic communication technology [5], [6]. In underwater acoustic communication systems, both bandwidth and power are severely limited due to the exponential (rather than polynomial) path-loss attenuation with This work was supported in part by the National Science Foundation under grants No.…”

“…This is a main feature that distinguishes underwater systems from wireless radio links. Based on these characteristics, network coding schemes [6]- [8] have been presented for underwater acoustic channels. One natural question is what are the fundamental capabilities of underwater networks in supporting multiple S-D pairs over an acoustic channel.…”