Press release

Satellite OBU Tollware – practical utilization in electronic toll systems

Description
We would like to introduce a new member of our portfolio of electronic toll on-board units: Tollware – a satellite on-board unit (OBU). We will describe this as yet smallest satellite OBU together with its functionalities including communication with the central system.

Miniature satellite OBU
OBU Tollware is based on ten year experience of Princip company in the segment of telematic and toll collecting on-board units. In spite of its tiny dimensions (65x110x25 mm) the unit contains an internal GNSS antenna, internal GSM antenna, backup 500mAh accumulator, super-sense GNSS receiver, quadband GSM/GPRS modem, 96MHz CPU, 8MB flash memory, inertial movement sensor, security tamper, socket (holder) for SAM encryption modules, infrared communication interface, USB port, five LED's and a push-button. The design of OBU Tollware enables anybody to install it in less than two minutes time. The installation consists of sticking the unit on the windscreen and connecting it to the vehicle power source. The unit can easily be powered from the cigarette-lighter socket or from any source of power 10-34V. The power cable is the only connection of OBU with the vehicle. Internal accelerometer can detect the vehicle motion in order to control the power management.

Operating system Seidlix has been developed by Princip since 1999 and is used in all Princip on-board units. It comes as no surprise that it is the basic software for OBU Tollware as well. The applications, which are part of the delivery, support both telematic and toll functions and provide for unit configuration and diagnostics, both locally using the infrared interface and USB port, as well as remotely by means of GPRS, SMS and data calls. Of course, upgrade of operating system, applications and geodata (virtual gantries or digital maps) by means of GPRS or data calls counts among the applications, too. The telematic functions include electronic log-book, calculation of distance covered, checking the driver's breaks for rest, etc. Implementation of a thin client for recording the vehicle route and of thick client functions based on the detection of virtual gantries or on mapmatching belong to the toll functions included. Encipherment of data sent by OBU is another important function, implemented either by added SAM module or by an internal processor supporting RSA 1024bit and 3DES algorithms.

Warranty of compatibility with future systems
OBU Tollware is a representation of an "intelligent client" able to process measured positions directly within the unit, sending only the results to the central system. Although the processing is implemented entirely within the OBU, we recommend to connect the unit to the central system via a proxy server, similarly as with current "thin clients". At this time, it is the only way how to produce a device now, which will remain compatible with European Electronic Toll Service (EETS) in the future and will comply with standards still under preparation. Communication via proxy server is the way how to preserve existing data structures and communication protocol implemented in the OBU. Communication with any central system and compatibility with standards of the future can then be achieved by a mere modification of the proxy server. This concept also guarantees the connection of satellite units with current toll systems without any need for major modifications of them. Additionally, this concept of proxy server allows for communication by proprietary protocol in the cellular network (between OBU and the proxy server), which is optimized for security of data transfer and for saving of communication costs. This concept of OBU Tollware communication is based on long year monitoring of the development of standards and projects like Mister, CESARE, RCI and corresponding Working Groups.

OBU Tollware operation
Let us describe the function of OBU Tollware in the electronic toll system in more detail. Having signed the contract for use of paid infrastructure in the service center, the user is given a OBU and installs it in his/her vehicle. Immediately following the installation, the unit connects to the central system by means of GSM/GPRS and of proxy server and receives an activation message with details of the contract and keys for encipherment of all following communications. This activation communication itself is enciphered, too, using a master key installed by the manufacturer. From now on, the OBU is active and can work normally, indicating its status to the user by means of LED's. Using the push button users can change current vehicle category.
As soon as the vehicle sets into motion, OBU leaves the power reduction mode, starts full operation and switches the GNSS receiver and the modem on. Having contacted the proxy server, the OBU reports the start of the journey and its internal status and transfers any possibly waiting data to the server. Any contact of the vehicle with the paid infrastructure is registered using either virtual gantries or mapmatching, according to the OBU setup. Detected segment numbers are transmitted to the proxy server (either immediately or later on, according to the setup), which will pass them in agreed format further to the central system. In this way, the OBU works until the end of journey when it contacts the proxy server again and transfers any remaining data. Fig. 1 depicts the procedure of communication between OBU and the central system.

Enforcement
Enforcement is an inseparable part of electronic toll system aiming at detection of vehicles without OBU or vehicles with incorrectly set vehicle category in OBU. The enforcement can either be stationary with automatic operation, or mobile under control of enforcement specialists. Although OBU Tollware contains no dedicated short range communication (DSRC) device, used for communication with enforcement in other systems, it is able to perform full enforcement as well. Additionally, the concept of enforcement without DSRC cuts the price of the whole system. The underlying idea is simple: data required for enforcement are not read from the OBU using DSRC but from the central system where they had been sent by the proxy server.

How does the stationary enforcement with OBU Tollware work? At its base are ANPR (automatic number plate recognition) cameras and laser scanners. The cameras recognize number plates of passing vehicles and laser scanners decide from their shape if they are eligible for payment or not. Number plates are compared with records in a central system database accessible via Internet. The response contains following pieces of information: does the contract for use of paid infrastructure by this vehicle exist, is the OBU operating normally, and, what vehicle category is set now? If no contract was found or the category detected differs from the actual shape of the vehicle, the enforcement gate sends the photograph of the vehicle together with other data to the center for further investigation.

Mobile enforcement can be performed on paid roads directly using an inspection vehicle or in parking lots where performed toll transactions can be verified. The procedure is similar to that of the stationary enforcement; however, due to more time available for checking of each vehicle here the proxy server can be contacted additionally and asked for more details about OBU function and transactions performed. If enforcement is performed on parked vehicles, direct communication with OBU using infrared communication interface is possible.

Due to sending diagnostics information into the proxy server, OBU problems can be detected automatically. This diagnostics can be considered part of the enforcement, too, because it enables us to discover wrong position of OBU (bad GNSS reception), bad power supply for OBU (frequent power failures), production defects of the OBU, or – last but not least – attempts to change OBU functionality (tampering).

Enforcement with OBU Tollware can be performed in the same way as with any other OBU but, moreover, automatic remote diagnostics is additionally possible thanks to the proxy server. Data collection from OBU by means of servers has yet another advantage: there is no need to position the reading device exactly against the tested vehicle, which is a frequent source of problems with DSRC.

Test results
The first testing series of OBU Tollware was produced in December 2007. It has been tested intensively since then both in the Czech Republic and in other countries, too. The testing includes also a real toll system now. No time consuming debugging of software is necessary as the same operating system and toll application are used in OBU Tollware as in all previous types of OBU produced by Princip. OBU Tollware is ready for deployment in toll systems right away.

To find out more, contact Jaroslav Altmann on the stand number 01.501S or at Princip by calling +420 257 210 904, emailing: altmann@princip.cz or by visiting the company’s website at: www.princip.eu

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