Functionality and structure of a complex system with nearly autonomic devices Janja Svečko1, Saša Klampfer2, Amor Chowdhury2 1 Ultra d.o.o., Cesta Otona Župančiča 23a, 1410 Zagorje ob Savi, Slovenia
[email protected] 2 Margento R&D d.o.o., Gosposvetska 84, 2000 Maribor, Slovenia
[email protected] conclusions and examples of similar systems and possibilities of such systems.
Abstract When we have a complex system, it is important to have integrated devices which are independent or at least almost independent. This ensures the proper functioning of the system, although a device (unit) breaks down, which does not cause a chain reaction of errors or failures in the system or a break down of the whole system. In this article we will give an example of an existing system, which is built with a large number of devices. The devices differ from some functionalities and housing, but all of them work nearly autonomous and support the basic functions of the system. In the article we explain the connections and communication types between the devices; as well we indicate the level of independence of them and reasons of dependence.
2. Complex system The system explained in this article is basically a system for management public transport and validations of passengers on buses using the RFID (Radio Frequency Identification) technology. But with its possibilities to upgrade and extend the functionalities of the devices integrated in the system, it became a complex network system with little less than 1000 computer devices. We can divide the system into three parts of use. The first primary part is the public transport. The second part covers public parking area; meanwhile the last third part is intended for other applications/locations. Every part has its appropriate hardware and software, which depends not only of the location of use, but also of the functionality. The connection between all parts is the contact less smart card, which uses the RFID technique for identification, validation or purchase of bus tickets, parking tickets or for other services payment. One of the benefits of the contact less smart card (further CLSC) is its possibility to act like a mobile wallet, on which the user can load money and use it in the system (prepaid card). One possible division of the system is regardless of it functionality. We again get three parts. The first part is the CLSC that communicates with the system, as mentioned before, through the RFID technology. The smart card intelligent and secure software structure allows use of several services at the same time. Besides automatic fare collection, the card can be used for parking check/pay, entrance check/pay, museums etc. The system also supports identification and payment with mobile payment solution. The second part of the system is the real time data centre. The centre makes the system very transparent and efficient. That is possible, because every terminal used in the system has a GPRS (General Packet Radio Service) connection (its own or via interface) or an IP connection. The real time data center consists of the: • Encode Unit, • MPS (Margento Processing System), • MPSA (Margento Processing System Administration).
Keywords: Complex system, autonomous, system errors, monitoring, terminals.
1. Introduction The Margento complex system is based on our own patent of carrying out a transaction with a mobile phone through the mPOS, aPOS and vPOS terminal, which also support RFID communication. The system consists of the so called “front-end” components including terminals, applications on the terminals, modulation procedures, encryption algorithms, etc., and “back-end” components including call server, access point, databases, processing server etc. To understand the functionality and working behaviour of the complex system, is in the second section explained the structure of the system and its individual components. Within the third section we describe used communication types in the system, and principle how they work. In fourth section we discuss about devices dependence in the system, and at the same time about the possible reasons of independency. With fifth (last) section we conclude the paper with
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All the terminals in the system present the third part. Basically we use in the system three different terminal types: mPOS, vPOS and taPOS. We will explain the functionalities and communication between the components later on. Using the real time data centre we are able to perform efficient defect monitoring where it is possible to solve them in a short time period. Due to the implemented broad range of data mining options we can help to improve demand planning if needed. In Figure 1 is presented the structure of the system based on the above mentioned functionality.
work independently and in the same time it ensures the autonomy of the system. More interesting and important for the company is the MPSA system, which is basically a web application, designed to control and manage the system. It is a connection between the company and devices in the system. In a user friendly form it shows all the data stored and recorded on the MPS. It is important for controlling transactions and devices involved in the system processes. The application enables online terminal monitoring, supporting various commercial models such as determine points of sale, regulating contracts between organizations, financial reports review for the organization, etc. Every session or action done in the MPSA is recorded in the database and the application log. MPSA supports also advanced features, such is remote terminal configuration. Terminal updates can be done by demand or progressively through transactions. By using MPSA we have a full control to select terminals which must be updated, and the moment of terminal update time can also be defined by user. The system does not include only terminals in public transport, but also terminals for public parking and other applications. They communicate via GPRS with the MPS and thus allow the use of the same media – contact less card for a wide range of activities. Each terminal in the system is equipped with a GPRS modem and supports RFID communication and the design of the terminal casing is specially designed to fit its purpose. mPOS (Figure 2); Margento mPOS mobile terminal is used for payment and account recharge operations as well as on – board tickets validity inspections. We can find it at the point of sale, tourist information centres, tourist attractions, fare inspectors, etc. The mPOS is also used as a service terminal, to display data from the status card or to synchronize terminals.
Validator
Fare inspector
public transport
Driver Terminal
Contactless card
Encode Unit
MPS
TaPOS
initialization
MPSA
public parking business logic
database
Service terminal
administration
End user (POS/POU)
Self-service kiosk
other aplications
Figure 1: The Margento system for public transport In the system we use MIFARE DESFire EV1 contact less cards, we do not use the contact less cards just for validations, but also as identification cards for sellers, conductors and service representatives. Service representatives are using it for identification and registration before using specially tailored terminals at point of sale and point of use. There are also other types of cards such as cards with special statuses, for example the status card (we read the data from the terminal – transactions, version, alarms and status of the terminal), pairing card (if there is placed more than one vPOS in the bus, we can synchronize the terminals to act as one), money collector card, etc. Every card that goes through the initialization procedure is recorded in the MPS. In general MPS consists of two parts, the first part is business logic for handling information’s between the database and user interface, where database present the second part. MPS represents the central part of the system. Without it, the devices in the system could not
Figure 2: mPOS vPOS (Figure 3); Margento vPOS ticket validator is used for public transit on – board ticket validation and payment. Within the existing system they are located
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inside public transit vehicles, fixed at a given height. Because of there location and massive use, their casing, graphical and audio user interface and application has to satisfy certain conditions; speed of validation, corresponding sounds and lights, resistance to various effects, appropriate security mechanisms, the ability to store transactions at connection loss with the MPS, data transfer rate toward the MPS etc.
location and with the connection to the vPOS on the buses supports several other functionalities, like: monitoring validations, reasons of rejections, buy extra tickets, a zone or line based payment system, etc. It also stores all data for several months, if the vPOS looses the connection to the MPS or has no more memory available.
3. Communication and connections in the system In the system we have four different types of communication techniques: • radio – frequency communication, • communication over GPRS, • communication over IP, • serial communication. To enable the communication between the terminals and center, it is necessary to enter the GPRS IP Address and the GPRS IP Port Number of the center, into every device, which access to the center. This is done with configuration files using a special program - Margento terminal Tool. If you look at the Figure 5, you can see all the connections between the terminals and the system. All devices are connected to the real time data center (system).
Figure 3: vPOS taPOS (Figure 4); Margento taPOS terminals serves as a contactless card reader/writer. It is a part of the self – service terminal, but it can also be used in many other applications, including parking solutions, various ticketing projects, etc. In the established system the taPOS terminals are located on self-service kiosks, parking meters, parking machines and ticketing kiosks. Due to their location and exposure to external influences and vandalism, their casing is adapted accordingly to these parameters.
TaPOS terminal
mPOS terminal
Service terminal
mPOS terminal
Self service terminal
Service terminal
vPOS terminal
TaPOS terminal
Parking meters, parking machines, ticketing kiosks
Validator
Driver Terminal
mPOS terminal mPOS terminal
Fare inspector POS/POU
Figure 5: Connections and communication in the system
The vPOS and mPOS terminals have integrated a GPRS modem, so they can communicate direct with the center over GPRS connection. In the case of taPOS they can establish a GPRS or IP connection. As mentioned, taPOS can be integrated into different devices (vending machines, self-service kiosks, parking meters, etc.). In cases when the external device has its own IP connection, the taPOS can access to the center through this IP connection. Such connection is usually made on the self service kiosks. taPOS and the external device are mutual connected over RS232 interface. In cases where IP connection is not available, the taPOS needs a GPRS modem to connect to the center
Figure 4: taPOS Beside the above mentioned terminals, the system also includes self service kiosks and driver terminals. The self service kiosks are free standing multipurpose and customizable terminals. The kiosk operates 24/7 and allows users to purchase blank contactless cards, recharge or buy tickets and therefore use several payment types; cash, credit cards, debit cards, mobile phone payments and card balance on the contact less card. The driver terminal is a touch screen user interface placed in driver vicinity. It enables automated vehicle
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via a GPRS channel. The solution is to connect the taPOS on an interface, which enables the GPRS connection. Margento has developed for such cases a special interface (Margento GPRS MDB), called MEGI (MDB Executive GPRS Interface). MEGI interface has integrated a GSM/GPRS module, which serves for establishing connection between taPOS and center, and it at the same time delivers a power supply to the terminal. This connection is used on parking meters and parking machines. On every bus we have placed two vPOS terminals and both of them are connected with the driver terminal via serial communication. The driver terminal operates independently and provides the vPOS terminals about the location, bus station, bus line, etc. This information’s are just additional for our system and are not important for the proper work of the terminal itself. The information’s would be important and necessary, if we would have a line or zone based payment system. We also do not have any dependence of the vPOS terminals, if one of them does not work the other one can. In the public transport we use also mPOS terminals as terminals for fare inspectors. The terminals work again completely independent of other terminals (vPOS or mPOS). If the conductor would like to start with the control, he has to sign in with his identification contact less smart card, and enter the unique bus number (ex.: registration number). Every action done by the conductor is send to the MPS and recorded. The mPOS terminal is used also as a service terminal in the public transport. The vPOS terminal has a screen, but displays only data important for the user. With the service terminal, we can prepare a service contactless card, which we approximate to the vPOS and obtain all necessary information’s about the terminal. Than we again approximate the card to the service terminal, where all read data are displayed. We get every important information for the service crew and support. The service terminal is also used for the taPOS terminals, which do not have any display. One of the functions of the service terminal is also synchronizing of vPOS terminals. After mounting the vPOS terminals in the vehicle, we have to synchronize both of them to act as one. This is done with a synchronizing card, which is prepared by the service terminal. With this procedure we also get information’s which vPOS terminal (serial number and terminal identification number) is on which bus and again store this data on the center. In every process mentioned above is also included radio – frequency communication, because the use of the contactless smart card as a medium for data transmission. mPOS terminals which are used in other applications, like kiosk, points of sale or other points of use, have the possibility to connect to the cash register via serial connection. These links serves just for a faster and easier work for the seller by issue the invoices. The
link does not influence on the proper work of the terminal, so we can use the terminal also without the connection to the cash register.
4. Dependence of devices All terminals/devices in the system are independent to a certain limit. The limit depends on the location of use and other devices on which terminals are integrated. For example the taPOS terminal is mostly dependent of other devices. If something is wrong for example with the self service kiosk, its IP connection or power supply, the terminal can not connect to the center. After reaching a time limit in which it can work offline (without the connection to the center), we can use just a few of all possible functions of the particular device. This time limit is individual for every group of terminals and is stored in every terminal. The reason for such a security lock is to ensure and enhance the security in the system. In the beginning of the article we said that the devices in the system work almost autonomous. They can not work fully independent, because the connection to the center. Not only that every terminal sends every transaction to the center, it also connects to the center with so called service calls. The center checks how often they establish a connection, if it is too often it is a sign that something is wrong with the device. The center also records all alarms from the device and separates them in critical and uncritical alarms. This information’s are important for the service crew and for the call center. With every service call the device checks if there is new black list or tariff on the center. That is one more safety mechanism in the system, because we can immediately add stolen or lost cards on the black list. Which is then send and uploaded on terminals, if someone next time uses a card, which is on the black list, the system will block the card and it becomes useless. The reactivation of the card is possible only with the encode unit and the initialization procedure. The system has also such a quick response to any change made on tariffs. If a terminal (for example vPOS) works offline and reaches the time limit, you can not buy tickets on the bus any more, but you can still use monthly tickets. On the mPOS if it is in the offline mode, you can not buy monthly tickets, but you can still use the function card info, etc. The connection of mPOS - es used in points of sale and points of use, to the center is important also for the function remote report. The report covers all sold tickets and charges for a specific time period on this terminal. One of the benefits to access to all terminals by the MPSA is the ability to shut down terminal or terminals, if the supplier or seller does not consider the contract with the company. The shut down function also becomes applicable when the terminal starts to behave strangely and the system safety is ensured.
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If we spread the terminals according to the independent operation, we can say that the mPOS terminals are the most autonomous computer devices. After the service call, checking black list and tariff it can work without any other device, it has its own power supply unit and charging circuit. It also has all periphery needed for a smooth communication with the user. The only limitation is the time limit in which it has to do the next service call to the MPS. Without the service call the functionality of the terminal is taken down to a limit. The second autonomous device in the system is the vPOS terminal. Compared with the mPOS it does not have its own charging circuit or battery, it also dose not have all the periphery for a full independent work. The service crew needs a service terminal to get all the data stored in the vPOS, but beside this it is a full independent computer device. It again needs just the service call, valid black list and tariff, so it can work autonomous. The dependency between the driver terminal and vPOS is just because some futures those were required from the company. If it looses the connection with the driver terminal it can again work without interruptions till the time limit, when it has to do again the service call. The most dependent computer device is, as mentioned before, the taPOS. Its periphery is minimal and it also does not have its own battery or charging circuit. For the proper work it needs a device with available IP connection or an interface for a GPRS communication. Like the other terminals (mPOS and vPOS), after establishing the connection to the MPS and made the service call, it can work independent from the device located on. Because it is mostly attached to different devices from different companies, is the taPOS in the slave position.
place without complications and did not affect the working process of the system. With the data stored in the MPSA the company has also access to huge amounts of statistical data. Such data helps us to optimize for example bus lines, to predict and analyze the rush hours and desired time intervals, lines that are mostly used, etc. The company has also a full control about the number of sold tickets on every point of sale. The data is accessible not just in the end of the given month, but every day at every moment. For the company is also very important to have control, how conductors carry out their work. With use of the identification conductor card before they start the controls, we have for every conductor the number and location of controls stored on the MPS and can be displayed on the MPSA.
Acknowledgement This research work is supported by Slovenian Technology Agency – TIA. Operation part financed by the European Union, European Social Fund. Operation implemented in the framework of the Operational Programme for Human Resources Development for the Period 2007-2013, Priority axis 1: Promoting entrepreneurship and adaptability, Main type of activity 1.1.: Experts and researchers for competitive enterprises.
References [1] Svečko, J., Kotnik, B., Mezgec, Z. in Chowdhury, A. The Margento automated fare collection system solution for public transport. 7th international conference on logistics & sustainable transport, Celje, Slovenia, June 24-26,2010, pp 263-280, ISBN 978-961-6562-39-3 [2] Rožič, B., Svečko, J., Mezgec, Z. and Chowdhury, A. (2009). Concept of the Margento contactles card system. Proceedings of the 18th Iinternational Electrotechnical and Copmputer Science Conference, Portorož, Slovenia, September, pp.35-38. [3] Sebasu, B., Nikolić, A., Zelenik, A., Mezgec, Z. and Chowdhury, A. (2008). Margento GPRS MDB interface. Proceedings of the 17th International Electrotechnical and Copmputer Science Conference, Portorož, Slovenia, September-October, pp.27-30. [4] http://www.nxp.com/documents/data_sheet/124533.pdf [accessed 26 March 2010] [5] Golob, C., Nikolić, A. and Kotnik, B. (2009). Development of hardware and software of validation terminal vPOS. Proceedings of the 18th International Electrotechnical and Copmputer Science Conference, Portorož, Slovenia, September, pp.39-42.
5. Conclusion The represented system can be used also in other environments, from entertainment industry to universities, colleges and schools. Campus limited cashless payments and access control, meal vouchers, internal payment and bonus loyalty point card, mobile gift vouchers, mobile coupons, etc. All these function’s can be integrated into one system. Nowadays we are starting with a very similar system, which are meal vouchers for students. At the process of developing such a complex system we tried to think in a wide range of use. We want a system that is dynamic and transparent. One of the many aims was to design a system, where it would be possible to implement any other service provider or application at every point of operation. Recently we had such a scenario where we had to implement a tourist card application into the existing system. This implementation did not afford just a new type of contact less card, but also an upgrade of all terminals participating in the system. The implementation took
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