Channel Modeling for Underwater Acoustic Network Simulation

Abstract

Simulation forms an important part of the development and empirical evaluation of underwater acoustic network (UAN) protocols. The key feature of a credible network simulation model is a realistic channel model. A common approach to simulating realistic underwater acoustic (UWA) channels is by using specialised beam tracing software such as BELLHOP. However, BELLHOP and similar modeling software typically require knowledge of ocean acoustics and a substantial programming effort from UAN protocol designers to integrate it into their research. This paper is a distilled tutorial on UWA channel modeling with a focus on network simulation, providing a trade-off between the flexibility of low level channel modeling via beam tracing and the convenience of automated channel modeling, e.g. via the World Ocean Simulation System (WOSS). The tutorial is accompanied by our MATLAB simulation code that interfaces with BELLHOP to produce channel data for UAN simulations. As part of the tutorial, we describe two methods of incorporating such channel data into network simulations, including a case study for each of them: 1) directly importing the data as a look-up table, 2) using the data to create a statistical channel model. The primary aim of this paper is to provide a useful learning resource and modeling tool for UAN protocol researchers. Initial insights into the UAN protocol design and performance provided by the statistical channel modeling approach presented in this paper demonstrate its potential as a powerful modeling tool for future UAN research.

LTDA-MAC v2.0: Topology-Aware Unsynchronized Scheduling in Linear Multi-Hop UWA Networks

“…This approach yields a statistical spread of channel conditions with variations in received signal and interference power, thus providing statistically more valid results. The wideband multipath channel with 24 kHz centre frequency and 7.2 kHz bandwidth was modeled using the BELLHOP beam tracing method described in [23]. Without loss of generality, these simulations use a threshold for interfering link detection of 0 dB Signal-to-Noise Ratio (SNR), i.e., all links with SNR ≥ 0 dB were marked with 1 in the interference matrix I, while all of the wanted links in the linear topology also have SNR > 0 dB.…”

“…Without loss of generality, these simulations use a threshold for interfering link detection of 0 dB Signal-to-Noise Ratio (SNR), i.e., all links with SNR ≥ 0 dB were marked with 1 in the interference matrix I, while all of the wanted links in the linear topology also have SNR > 0 dB. The SNR is calculated using the analytical ambient noise model with 10 m/s wind speed and 0.5 shipping activity factor [23]. The other parameters for the 2 km and 20 km pipeline scenarios, respectively, are:…”

Performance of Linear TDA-MAC in Full-Duplex Underwater Acoustic Chain Networks

“…A further benefit of considering relatively short range acoustic communication is the provision of regular monitoring points for the detection of problems such as leaks and movement of pipelines. In furtherance, the BELLHOP beam tracing method described in [25] is used to generate the statistical underwater channel characterization for the considered cases. A wide range of parameters based on the features of acoustic nano modems are considered.…”

FD-LTDA-MAC: Full-Duplex Unsynchronised Scheduling in Linear Underwater Acoustic Chain Networks

“…Although there are several available propagation models, such as ray tracing, normal mode, parabolic equation, wavenumber integration, energy flux, finite difference, and finite element models [31], the acoustic propagation model employed is based on the BELLHOP [26] beam tracing method described in [32]. The choice is influenced by computational cost and model efficiency with respect to topology and application scenarios.…”