An investigation of short range electromagnetic wave communication for underwater environmental monitoring utilising a sensor network platform

• Main Author: Abdou, Ahmed Abdallah
• Other Authors: Shaw, Andrew ; Mason, Alex; Al-Shamma'a, Ahmed Ibrahim
• Published: Liverpool John Moores University 2014
• Subjects: 621.384
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.625107

Current state of the art water communications systems rely on optical and acoustic propagation. But these have underperformed in many applications. Wireless Sensor Network (WSN) using radio communication underwater is state of the art. The frequency of operation and the antenna are the big challenges that if unlocked, will present many advantages. The aim of this research is to investigate short range electromagnetic wave communication for underwater environmental monitoring utilising a sensor network platform. Theoretical study and preliminary experiments have confirmed that ISM (industrial, scientific and medical) band at 433MHz was suitable for potable and freshwater communication. Traditional antennas have been constructed, tested and modelled in a High Frequency Simulator Structure (HFSS) but were found unsuitable for use underwater. A 433MHz bowtie antenna was modelled in HFSS and shown to perform well in both air and potable water without any matching circuit. The antenna was prototyped on a printed circuit board, waterproofed and tested successfully in a tank. Furthermore to eliminate RF crosstalk, a battery powered wireless transmitter that generated a carrier signal at 433MHz, was used successfully in the laboratory tank, and during experiments that were repeated in freshwater in Liverpool Stanley Canal. This range, in excess of 5m, was large enough to combine the bowtie antenna with off the shelf, low power transceivers operating at the 433MHz, and specific sensors to form a WSN for potable and freshwater applications. The contribution to knowledge is the experimental demonstration of reliable communication at 433MHz using a broadband antenna which unlocks the potential of underwater WSN applications, including applications in water quality measurement, using radio communication.