On the Use of Wireless Technologies for Shipboard Monitoring Systems

Abstract

Current shipboard monitoring systems use extensive lengths of cables to connect sensors to control units. Replacing wired connections by wireless ones may be an efficient solution to reduce the ship weight and cost. Ships are characterized by a specific metallic environment which can severely decrease the efficiency of wireless networks due to signal attenuation and multipath effects. In this paper, we present a feasibility study of a Wireless Sensor Network (WSN) using ubiquitous technologies on board vessels. A measurement campaign has been conducted on board a ferry to investigate the radio propagation challenges of wireless communications in this particular environment. Path loss models have been obtained for typical shipboard environments.Engineering rules concerning the placement and the number of communication nodes needed to cover the decks and maintain the network connectivity have been determined. Based on these results, an IEEE 802.15.4 compliant WSN has been tested on board the same ferry. Sensor nodes have been placed on the four decks of the ferry and the base station has been placed in the control room located in the bottom deck. Results show an excellent reliability with respect to transmission ratio of sensor nodes and a significant connectivity between nodes located in different compartments and decks separated by metallic watertight doors. Therefore, many research groups have started to investigate the possibility to replace the huge amount of cables by wireless connections using ubiquitous technologies. In [2], authors explore the feasibility of wireless communications for both intra-and inter-compartment shipboard communication within various naval vessels. In [3], it has been demonstrated that the radio propagation in large shipboard areas might be characterized by almost a free space law, while no path loss model has been found for corridors. In Moreover, multipath effects leading to multiple delayed copies of the transmitted signal at the receiver may also decrease the radio communication data rate within ships. These characteristics make difficult the wireless communication between nodes placed in different rooms or different decks. Therefore, an EM propagation study must be performed on board a vessel before network deployment. This study is necessary in order to verify the feasibility of inter-compartments and inter-decks wireless communication and to efficiently place the nodes to have a good network connectivity. In this paper, a complete feasibility study of a WSN on board a ferry is presented. First, an EM propagation study is performed in three typical environments on board the ferry. Path loss models are determined and different communication configurations such as communication between different rooms or different decks are considered. The results of these measurements are then used to determine some engineering rules concerning the location and the number of nodes needed to ensure full radio coverage of the ship and whole network connectivity. Secondly, a WSN based on...

Location Algorithm for Nodes of Ship-Borne Wireless Sensor Networks

“…(3) The nodes on different decks cannot communicate directly. They mainly communicate through the repeaters located at the stairs between decks [10].…”

Performance analysis of a hierarchical shipboard Wireless Sensor Network

“…This section describes the measurement campaigns conducted on board a ferry, including a radio propagation study and a WSN deployment. This work is detailed in [5].…”

Risk-based EMC Approach for the Ship's Semi-enclosed Reverberant Indoor Environment to evaluate EMI generated by Wireless Devices

“…Replacing wired interconnections with wireless devices in a ship provides several benefits in terms of cost, space, and weight [1]. The usage of wireless devices is on the rise, and the complete replacement of wired devices is closer than anticipated [2].…”