Wireless nodes at sea
On-board wireless networks could provide a cost-effective means of linking monitoring systems aboard large ships such as passenger ferries and merchant ships, despite the obstruction of watertight doors and dense steel bulkheads.
In a paper published in the Institution of Engineering and Technology's journal Electronics Letters, researchers at the Institute of Electronics and Telecommunications of Rennes (IETR) report their finding that radio leakage between metallic watertight adjacent chambers is of a level sufficient for communication between network nodes in a wireless sensor network (WSN).
Tests using a MIMO channel sounder at 2•2 GHz on the lower decks of a modern car ferry revealed that radio signals could pass through the edges of watertight doors, though they were heavily attenuated.
On-board monitoring systems are an essential part of a ferry-sized vessel, which requires kilometres of cabling to connect thousands of sensors for systems monitoring, internal messaging and on-board communications. A wireless solution would reduce the cost of installation and the complexity of later upgrading systems to new specifications.
Another major advantage of a wireless solution over heavy cabling would be reduced weight. A WSN could lead to an increase in a ship's payload or reduce its fuel consumption, with positive effects on the environment and financial costs.
Next steps for the researchers will include determining the engineering rules necessary to install a WSN on a ship; adapting existing monitoring systems to support wireless devices; and testing the networks in difficult conditions. The researchers also plan to explore the scope for other ship-based wireless applications, such as on-board wireless local area networks, wireless personal area networks and cordless telephones for crew.