By Veronika Roux
Thales Industrial Services
Thales Industrial Services, as a system integrator, recently teamed up with Thales Tracs, the product provider, to offer Mobil a solution to fleet tracking in an austere environment in Cameroon. The service could also be adapted for tracking any type of offshore vessel, including drilling, pipelay, and seismic vessels, and platform support ships.
Thales IS' objective was to enable Mobil's headquarters control facility, based in Doula, to track and communicate in real time with the company's fleet of vehicles, while on the road to the border with Chad, 1,000 km to the north. A special concern for Mobil is the safety of staff and their vehicles' contents while traveling to their final destination.
Architecture of the Tracs SATC positioning system as designed for Mobil in Cameroon.
As the local GSM mobile network is of poor quality and unreliable, Thales IS proposed the Real Time Tracking System, which has been developed based on the Tracs SATC vehicle positioning system created by Thales Tracs in the UK.
The Tracs SATC Vehicle Positioning operates through Inmarsat-C satellites. It is the most effective method of communicating with vessels or vehicles beyond the range of normal terrestrial communications and is ideal for a range of safety, security, and management applications.
For the Cameroon application, the main station is based in Central Command in Douala, and includes a standard PC, an antenna combined Inmarsat C/GPS, a GPS receiver, and Tracs locator/map software.
Equipment needed on the four-wheel drive mobile units includes a Tracs SATC mobile set, including land mobile satellite transceiver, and integrated 8-channel GPS receiver (TT-3022C), and a land GPS antenna.
The Tracs-SAT/C system introduces a valuable range of safety, security, and management benefits through enabling an offshore operator's control center to communicate with vessels or vehicles anywhere in the world (except extreme polar regions). The compact and lightweight Tracs-SAT/C unit includes a GPS receiver that supplies position information accurate to within 15 m.
The unit can be programmed to automatically transmit its location and other data at designated intervals. Transmissions can also be triggered by specific events, or the control center can poll the unit. A typical automatic transmission will cover identification of the mobile unit, its latest geographical position, date and time for that position, the course and speed of the vessel or vehicle and the condition of the system. This message could optionally include details such as fuel reserves or load status.
Tracs-SAT/C also features a two-way messaging facility between the mobile unit and central control, and between other SAT/C mobiles. Each unit is assigned a data network identity (DNID) number that enables messages to be broadcast via the land earth station (LES) to individual mobiles or to designated groups of mobiles within the system.
Tracs-SAT/C permits message delivery via fax, telex, X.25, and e-mail. Also included are the standard PU/PA programming formats as well as a new advanced "Connection" reporting format with multiple DNIDs, independent reporting timers, and global ocean area pre-programming.
Data is delivered to the control center using the store and forward messaging service. This is undertaken through a dial-up modem to the Inmarsat "post box" (PSTN), by a delivery-dedicated high-capacity X.25 line. A separate mobile terminal linked to the transceiver via the RS 232 connection provides pre-configured messaging. The mobile unit can also have its own e-mail address, which enables it to transmit and receive messages using an Internet connection at the LES.
The low power consumption of Tracs-SAT/C is enhanced by a sleep mode function that enables both timer and event controlled wake-up routines. Depending on reporting frequency, power consumption is typically 30-280mW.
Vehicle polling/positional data and geographical display can be provided using Thales Tracs Locator/Map software, which provides easy visualization of the mobile units being tracked. The software is available in a choice of configurations appropriate to specific applications, but typically comprises an intelligent mapping and display package designed specifically for Tracs SATC applications. This package has been designed primarily to display the real-time location of all vessels and to act as a messaging terminal for sending and receiving text messages to and from vessels. The package also includes options to establish both inclusion and exclusion delineation zones and yes and no-go, which can, if required, trigger alarm states for vessels that violate the zone protocol.