Analysis of Behaviour of EM Waves with Different Environmental Factor in Underwater Communication

Abstract

Electromagnetic (EM) wave–based underwater communication has emerged as a promising alternative for short-range and low-latency applications where acoustic and optical techniques face inherent limitations. However, the propagation behaviour of EM waves in seawater is strongly influenced by environmental factors such as frequency, salinity, depth, and medium stratification, which significantly constrain system performance. In this study, a comprehensive simulation-based analysis is carried out to investigate the behavior of electromagnetic waves in underwater environments under varying environmental conditions. A MATLAB-based numerical framework is developed to evaluate key propagation characteristics, including attenuation, path loss, penetration depth, phase delay, and the effects of layered seawater models, over a frequency range of 10 kHz to 100 MHz. Based on the obtained results, two practical design-oriented outcomes are derived: a frequency–distance feasibility map that delineates operational and non-operational regions for underwater EM communication, and a critical frequency threshold that defines the maximum usable frequency as a function of seawater salinity. The results reveal that attenuation increases sharply with frequency and salinity, layered seawater structures introduce additional propagation losses, and feasible communication ranges rapidly shrink at higher frequencies. The proposed analysis and derived feasibility metrics provide valuable insights and practical guidelines for the design and optimization of underwater electromagnetic communication systems under realistic environmental conditions.

Introduction

The text investigates underwater electromagnetic (EM) wave–based communication as an alternative to traditional acoustic and optical methods for short-range, low-latency marine applications. While acoustic systems support long ranges, they suffer from low data rates and high latency, and optical systems offer high data rates but are limited by turbidity, absorption, and alignment issues. EM communication is robust to turbidity and offers low latency, but its performance is severely constrained by the high electrical conductivity of seawater, which causes strong signal attenuation and sensitivity to environmental conditions such as frequency, salinity, depth, distance, and stratification.

To address limitations in prior research—namely simplified assumptions and lack of practical design guidance—the study presents a MATLAB-based simulation framework that analyzes EM wave propagation in both homogeneous and layered seawater models. Key propagation metrics, including attenuation, penetration depth, path loss, and phase behavior, are evaluated over a wide frequency range while accounting for environmental variability.

The results show that attenuation increases rapidly with frequency, making low frequencies more suitable for longer communication ranges. Penetration depth decreases sharply with increasing frequency and higher salinity, leading to the identification of a salinity-dependent critical frequency threshold beyond which EM communication becomes impractical. Comparisons between homogeneous and layered seawater models reveal that simplified homogeneous assumptions underestimate losses, while layered models more accurately capture realistic ocean stratification effects.

Based on these findings, the study derives two practical design tools: a frequency–distance feasibility map that clearly identifies operational limits, and a critical frequency threshold linked to salinity. These contributions provide actionable insights for frequency selection, range planning, and feasibility assessment of underwater EM communication systems under realistic environmental conditions.

Conclusion

This paper presented a comprehensive simulation-based investigation of electromagnetic wave propagation in underwater environments under the influence of key environmental factors, including frequency, salinity, water depth, communication distance, and medium stratification. Using a MATLAB-based numerical framework, fundamental propagation characteristics such as attenuation, path loss, penetration depth, phase delay, and the effects of homogeneous and layered seawater models were systematically analyzed over a wide frequency range. The results confirm that electromagnetic wave attenuation increases sharply with frequency and salinity, leading to rapid degradation of communication range at higher frequencies. Phase delay was observed to increase cumulatively with depth, indicating potential challenges for phase-sensitive underwater communication schemes. Furthermore, layered seawater models exhibited higher attenuation compared to homogeneous assumptions, demonstrating that simplified models may underestimate propagation losses in realistic stratified underwater environments. Beyond conventional propagation analysis, this study derived two design-oriented outcomes from the simulation results. First, a frequency–distance feasibility map was obtained, explicitly identifying operational and non-operational regions for underwater electromagnetic communication. This representation provides a practical visualization of communication limits and directly links operating frequency with achievable range under given environmental conditions. Second, a critical frequency threshold was identified from penetration depth characteristics, defining an environment-dependent upper bound on usable frequency as a function of seawater salinity. Together, these derived metrics translate fundamental electromagnetic behavior into actionable design guidelines. Overall, the findings demonstrate that underwater EM communication is best suited for short-range applications at low frequencies and that environmental variability plays a decisive role in determining system feasibility. The proposed feasibility-based analysis framework extends existing studies and provides a more practical foundation for the design and optimization of underwater electromagnetic communication systems.

References

This paper presented a comprehensive simulation-based investigation of electromagnetic wave propagation in underwater environments under the influence of key environmental factors, including frequency, salinity, water depth, communication distance, and medium stratification. Using a MATLAB-based numerical framework, fundamental propagation characteristics such as attenuation, path loss, penetration depth, phase delay, and the effects of homogeneous and layered seawater models were systematically analyzed over a wide frequency range. The results confirm that electromagnetic wave attenuation increases sharply with frequency and salinity, leading to rapid degradation of communication range at higher frequencies. Phase delay was observed to increase cumulatively with depth, indicating potential challenges for phase-sensitive underwater communication schemes. Furthermore, layered seawater models exhibited higher attenuation compared to homogeneous assumptions, demonstrating that simplified models may underestimate propagation losses in realistic stratified underwater environments. Beyond conventional propagation analysis, this study derived two design-oriented outcomes from the simulation results. First, a frequency–distance feasibility map was obtained, explicitly identifying operational and non-operational regions for underwater electromagnetic communication. This representation provides a practical visualization of communication limits and directly links operating frequency with achievable range under given environmental conditions. Second, a critical frequency threshold was identified from penetration depth characteristics, defining an environment-dependent upper bound on usable frequency as a function of seawater salinity. Together, these derived metrics translate fundamental electromagnetic behavior into actionable design guidelines. Overall, the findings demonstrate that underwater EM communication is best suited for short-range applications at low frequencies and that environmental variability plays a decisive role in determining system feasibility. The proposed feasibility-based analysis framework extends existing studies and provides a more practical foundation for the design and optimization of underwater electromagnetic communication systems.

Copyright

Copyright © 2026 Girish Kumar Tiwari, Pankhuri Vapta. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.