Artykuły :: Transport :: Conference papers
|Technology of electronic fee collection within ITS|
Rastislav PIRNĂK, JiĹĂ ZAHRADNĂK, Peter CIGĂN
1. DSRC TECHNOLOGY FOR EFC SYSTEM
Microwave technology of Electronic Fee Collection (EFC – DSRC) realizes transfer of identification data from On Board Unit (OBU), placed within the car, to control gate. It most often operates in transmission band of 5,8GHz. Gates, which serve as communication and control point, are usually equipped with DSRC communication unit and with control video system, which can recognize vehicles’ registration number (SPZ in Slovak) and if match between SPZ and electronic data appears, data is sent to the center for further processing. Overall number of gates in close EFC-DSRC system is proportional to the number of inputs and outputs from paid sections. In open EFC-DSRC system it is necessary to organize gates in such a way that their locations trace the way and its incoming and outgoing branches. EFC-DSRC system schema, introduced in Fig.1, provides view to the automatic lane and its technological equipment. Fig.2 presents arrangement of communication zones of EFCDSRC Automatic lane.
Fig.1. EFC–DSRC System
Fig.2. EFC–DSRC Communication zones
2. GNSS-CN TECHNOLOGY FOR EFC SYSTEM
Technology of Global Navigation Satellite System – Cellular Network (GNSS-CN) through satellite location Global Position System (GPS) recognizes paid parts of infrastructure. After passing predetermined number of segments (unit sectors), information about number of segments is transferred to the central proceeding system through a network of mobile operators – Global System for Mobile Communications (GSM). Described situation is presented in Fig.3 and communication through GSM is presented in Fig.4. Since OBU is equipped with control unit and software, it’s not necessary to equip road infrastructure with control gates. This technology supports quick system adaptability at unexpected change of road infrastructure conditions. Elements like road infrastructure expansion, partial changes on the road (accidents, detours, working activity) and temporal traffic restrictions should be quickly installed into the system from one central control point.
Fig.3. Arrangement of toll points in EFC GNSS-CN system
Fig.4. EFC GNSS-CN system
3. OBJECT ORIENTED MODELLING OF ACTIVITIES OF EFC-DSRC AND EFCGNSS-CN SYSTEMS
Both EFC systems are up to Europe union standards for electronic fee collection systems deployed after 01.01.2007. Basic model of EFC-DSRC system and model of EFCGNSS- CN system were created according to description of operating systems with microwave type of communication between vehicle and EFC-DSRC system.
Several diagrams (like Use Case Diagram – UCD, Class Diagram – CD and Sequence Diagram – SD), which describe activity of both systems, were created by the using of Rational Rose software tool. Just for illustration, two of them are introduced in this paper. Use Case Diagram of EFC-DSRC system is presented in Fig.5 and UCD of EFC-GNSS-CN is introduced in Fig.6. Model of EFC-GNSS-CN system was created regarding recommendations defined by .
In contrast to common class design, as defined by , some classes of EFC-GNSS-CN system are supplemented and extended by attributes and recommendations of Electronic fee collection systems defined for ITS.
Fig.5. Designed Use Case Diagram of EFC-DSRC
Class diagrams represent particular classes of EFC system. Each class of EFC system is responsible for execution of predefined and assigned functions. Main functions that must be realized by both systems regardless of their technical realization are as follows:
• locate vehicle position,
• realize communication between User – OBU – and EFC system,
• charge fees and realize payments in resident EFC system of national operator.
Fig.6. Designed Use Case Diagram of EFC-GNSS-CN
4. DESIGN OF OBU CLASS FOR EFC- GNSS-CN SYSTEM
Requests to design and add operations (Table 1) and attributes (Table 2) of particular classes of EFC-GNSS-CN system have appeared in the frame of project CONNECT. Class OBU (Fig. 7) is responsible for processing of information, which comes from other system classes. It handles and updates data, which is necessary for payment execution in superior subsystem.
By the using of public mobile operators, OBU class sends to the superior subsystem called Central system of fee collection (Fig.3) data that is necessary for a payment, and it is responsible for displaying of payment information on the vehicle’s display.
Fig.7. OBU class of EFC GNSS-CN system
Table 1. Chosen operations designed for OBU class of EFC- GNSS-CN system
Table 2. Attributes and their exact definitions
Main topic of Domain no. 8 of international project CONNECT named “ITS architecture in Slovakia – Modeling of services and functions of EFC satellite principle in Rational Rose environment” was modeling and evaluation of both systems described in this paper. Achieved knowledge and comparisons will be transformed to recommendations that should support the selection process of electronic fee collection systems for traffic area in Slovak republic.
Some comparison criteria based on experiences of composite authors published in  and  were specified during the process of design and modeling of EFC-GNSS-CN system. Based on these criteria, the comparison of described two dominating EFC systems was possible. Some chosen criteria are presented in Table 3. Table 4. summarizes advantages and disadvantages of both systems.
Table 3. Comparison of EFC-DSRC and EFC-GNSS-CN systems
Table 4. Advantages and disadvantages of described systems
Recognition, evidence and following legal disciplinary action in EFC-DSRC system observes high level of efficiency. In this case, the system closeness seems like an advantage. Experiences in area of EFC-GNSS-CN systems are still not available. Whereas it’s an open electronic system, it is necessary to expect an abuse of the system. So, it is necessary to develop safety mechanisms to reduce the risk of abuse to economically acceptable level. Both described systems meet requirements defined by relevant European standards. It is necessary to unify technical properties of EFC interfaces from multiple vendors to prevent technological incompatibility.
This work has been supported by the Agency for support of science and technique through the financial help of project no. APVV-20-P00705 and with (particular) support of Grant Agency of the Slovak Republic VEGA, grant no.1/1044/04 "Theoretical foundations for implementing e-Safety principles into intelligent transportation systems".
 ENV ISO 17575 Road Transport and Traffic Telematics (RTTT) – Electronic Fee Collection (EFC) – Application Interface Definition for Global Navigation Satellite Systems and Cellular Networks (GNSS/CN)
 Ĺ VEC, J., ZAHRADNĂK, J., Objektovo orientovanĂ˝ model „ELEKTRONICKĂ VYBERANIE POPLATKOV“, In: Proceedings of conference ELEKTRO 2004, pp. 170-174, (in Slovak)
 ZAHRADNĂK J., DADO M., PIRNĂK R.: Vybrané sluĹžby IDS v podmienkach SR, In: Proceedings of abstracts of conference Intelligent Transport Systems - pp. 81-82, (in Slovak)
Rastislav PIRNĂK, JiĹĂ ZAHRADNĂK, Peter CIGĂN
Department of Control and Information Systems, Faculty of Electrical Engineering, University of Ĺ˝ilina