Design of a Practical Underwater Sensor Network for Offshore Fish Farm Cages

Area of Science:

• Marine engineering
• Underwater sensor networks
• Aquaculture technology

Background:

• Offshore fish farms require reliable monitoring systems.
• Existing underwater sensor networks face challenges with wire breakage and maintenance.
• Current solutions lack robustness in harsh marine environments.

Purpose of the Study:

• To design a practical and robust underwater sensor network for offshore fish farm cages.
• To propose a mixed wireless-wired approach to overcome limitations of traditional wired networks.
• To analyze the network's performance, power efficiency, and compliance with industry standards.

Main Methods:

• A serial arrangement of identical sections with wired and wireless interconnections was developed.
• An analytical model was created to study power transfer efficiency and current distribution.
• Simulations were used to evaluate the impact of parasitic resistance.
• Experiments were conducted on a 30m deep network with 6m node spacing.

Main Results:

• The proposed mixed wireless-wired network demonstrates robustness against cable breakage.
• Sensor nodes before a short circuit maintain operation, with minimal runtime reduction (≤4.07%).
• The design shows compliance with the ISO 11784/11785 HDX standard.

Conclusions:

• The hybrid wired-wireless sensor network design offers a resilient solution for offshore fish farms.
• Wireless interconnections improve maintainability and system uptime during damage.
• The proposed network effectively addresses the challenge of underwater cable integrity and ensures continuous monitoring.