Underwater Wireless Sensor Communications in the 2.4 GHz ISM Frequency Band

TLDR

Underwater communication is limited by low data rates at low frequencies and degraded by reflections, refraction, and energy dispersion, making close‑proximity, high‑bandwidth sensor deployments challenging. The study proposes using the 2.4 GHz ISM band for underwater wireless sensor networks in close‑proximity scenarios and develops experimental models for fresh‑water EM communication. Wireless sensor nodes were deployed in a real scenario, and their performance was evaluated across multiple frequencies, modulations, and data rates, then compared with existing systems. Tests showed short communication ranges but high data‑transfer rates, with the system suitable for precision monitoring of contaminated ecosystems or deep‑device communication.

Abstract

One of the main problems in underwater communications is the low data rate available due to the use of low frequencies. Moreover, there are many problems inherent to the medium such as reflections, refraction, energy dispersion, etc., that greatly degrade communication between devices. In some cases, wireless sensors must be placed quite close to each other in order to take more accurate measurements from the water while having high communication bandwidth. In these cases, while most researchers focus their efforts on increasing the data rate for low frequencies, we propose the use of the 2.4 GHz ISM frequency band in these special cases. In this paper, we show our wireless sensor node deployment and its performance obtained from a real scenario and measures taken for different frequencies, modulations and data transfer rates. The performed tests show the maximum distance between sensors, the number of lost packets and the average round trip time. Based on our measurements, we provide some experimental models of underwater communication in fresh water using EM waves in the 2.4 GHz ISM frequency band. Finally, we compare our communication system proposal with the existing systems. Although our proposal provides short communication distances, it provides high data transfer rates. It can be used for precision monitoring in applications such as contaminated ecosystems or for device communicate at high depth.