Measurement-based simulation of underwater optical networks

The increasing interest in the application of optical communications to underwater communications and networks calls for reliable simulation models, that allow a system designer to realistically assess the performance of optical systems before actual deployment in water. In this paper, we present an optical channel model that is based on samples of the total attenuation coefficient and of the solar light irradiance taken during the NATO STO CMRE ALOMEX'15 scientific cruise, in different water conditions. The data set includes both strong and mild solar illumination conditions, as well as a number of different settings for the light absorption and scattering coefficients. We implement the model as part of the DESERT Underwater network simulator, and employ it to show that the throughput of underwater optical links depends not only on the distance between the transmitter and the receiver, but also on the depth at which the devices are deployed. The corresponding insight is empirically validated in dry tests and lake experiments using a proof-of-concept optical modem, and helped drive the next stage of the modem development.