WO2007128881A1

WO2007128881A1 - Method of transferring data between a terminal and a central unit in a mobile data acquisition system

Info

Publication number: WO2007128881A1
Application number: PCT/FI2007/050259
Authority: WO
Inventors: Pekka PÄKKILÄ; Hannu Niemitalo
Original assignee: Pancomp Electronics Oy
Priority date: 2006-05-09
Filing date: 2007-05-08
Publication date: 2007-11-15
Also published as: EP2020119A4; EP2020119A1; FI20060445A; FI118712B; FI20060445A0

Abstract

A method of transferring data between a terminal (Ln) and a central unit (1) in a mobile data acquisition system, which comprises in the central unit and terminals corresponding means and functions (6, 7) for transferring data through one or more mobile telecommunication networks (2, 3) by using several alternative data transfer methods and services (A, B, C, Cl, C2, D), and in which method a terminal (Ln) is activated for data transfer for essentially short data transfer sessions in the purpose of minimizing current consumption, is characterized in that the use of alternative data transfer methods and services during the data transfer sessions is controlled in the terminal (Ln) by individual control data sent to the terminal by the central unit (1), whereby the control is based at least on minimizing the data transfer costs in addition to minimizing current consumption.

Description

METHOD OF TRANSFERRING DATA BETWEEN A TERMINAL AND A CENTRAL UNIT IN A MOBILE DATA ACQUISITION SYSTEM

FIELD OF THE INVENTION The invention concerns a method of transferring data between a terminal and a central unit in a mobile data acquisition system. In more detail, the invention concerns the above- mentioned method in a data acquisition system which comprises a central unit and several terminals as well as in the central unit and terminals corresponding means and functions for transferring data through one ore more telecommunication networks by using several alternative data transfer methods and services, e.g. circuit-switched data transfer, short message service (SMS) and packet mode data transfer (GPRS), in which method a terminal is activated for data transfer for essentially short data transfer sessions in the purpose of minimizing current consumption.

The duration of an essentially short data transfer session, including the activation of the means and functions for data transfer and the sending and receipt of data, is typically from several tens of seconds to some minutes.

This kind of system may be applied to supervising the work of mobile staff at different work sites and gathering information related to it, for example.

BACKGROUND OF THE INVENTION

It is known to combine terminals of a data acquisition system and a mobile telecommunication network to create a mobile data acquisition system. One mobile data acquisition system according to the above definition is presented, for example, in the applicant's earlier international patent application WO 2005081564. In the solution of the above WO publication, that part of the terminal which works in a mobile telecommunication network is kept dominantly in a deep rest state and is activated for data transfer for essentially short data transfer sessions according to individual control data obtained from the central unit. The aim of this is to minimize the current consumption of the terminal. At the same time, the use of the terminal is made as simple as possible and a very high operational dependability is realized in the system.

In data transfer, the solution of the WO publication prefers transfer by a text message, e.g. by the short message service (SMS) of the GSM system. As the alternatives, e.g. data calls possible in GSM networks or data transfer possibilities offered by more advanced networks, like GPRS and UMTS networks, are considered. The short message service of the GSM network suits well for sending and receipt of small data amounts. By using the SMS service, data may be sent as PDU messages including 160 x 7 bits = 1120 bits, and several messages are sent when the amount of data is larger. An advantage of using this service is that there is no need to establish a connection between the sender and the recipient, because text messages keep awaiting in a message center from which the recipient obtains them immediately when becomes available through the network. Normally, a certain sum is charged for each message. In data transfer by means of text messages, advantageous sending times or possibly advantageous terms of agreement may be utilized. As a mobile data acquisition system, like a work management system, is becoming wider and the data amount per each terminal in general and the data amounts transferred at a time become larger, data transfer costs, however, make a remarkable part of the operation costs of the system. Therefore, it is reasonable to consider alternative data transfer methods. The data transfer speed in the data calls of the GSM system is of the order of 6 kilobits per second, and data transfer is usually charged on the basis of connection time. GSM operators offer also a higher-speed data transfer service named HSCSD (High Speed Circuit Switched Data). The data transfer speed is there increased by bundling together several simultaneous data connections. Also users of this service are normally debited on the basis of connection time.

The GPRS network and its services work presently in a large part of the area covered by the GSM network. In GPRS services, data transfer is performed in packet mode which makes possible to change packets with other packet mode networks, like the Internet. A connection for data transfer may be established from one point to another, or data may be transferred as text messages or through e-mail service. From a user's point of view, it is essential that the services are normally charged on the basis of the amount of transferred data. The fees of the services may develop e.g. in such a way that the cost of transferring one kilobyte through a GPRS network is smaller than the cost of transferring one text message, i.e. 1120 bits, through the SMS service of GSM network.

Mobile communication services are developed further all the time. Further development of GPRS has provided e.g. EDGE (Enhanced Data Rates for GSM Evolution), the operation and the manner of charging of which are similar to GPRS services and the data transfer speed of which is remarkably higher. A third generation mobile communication network, UMTS (Universal Mobile Telecom System), is already working together with GSM networks in the largest cities. Data transfer speed is there increased further, and especially the delays in the connections are reduced. SUMMARY OF THE INVENTION

An object of the invention is to further improve the operation of the mobile data acquisition system concerned by the invention and also to make it economically as advantageous as possible. To achieve this object, a method according to the invention of transferring data between a terminal and a central unit in a mobile data acquisition system, which comprises a central unit and several terminals and in both the central unit and terminals corresponding means and functions for transferring data through one or more mobile telecommunication networks by using several alternative data transfer methods and services, and in which method a terminal is activated for data transfer for essentially short data transfer sessions in the purpose of minimizing current consumption, is characterized in that the use of alternative data transfer methods and services during the data transfer sessions is controlled in the terminal by individual control data sent to the terminal by the central unit, whereby the control is based at least on minimizing the data transfer costs in addition to minimizing current consumption.

The control is additionally based on ensuring the success of the data transfer. In one embodiment of the method, a general instruction is given to the terminal about the use of data transfer methods and services during data transfer sessions.

In another embodiment of the method, a special instruction about the use of data transfer methods and services is given for a certain data transfer session or data transfer sessions belonging to a certain class.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention and some of its embodiments are described in more detail in the following with reference to the accompanying drawings, in which:

Fig. 1 presents a general example of the mobile data acquisition system in which the solution according to the invention may be realized;

Fig. 2 presents a more detailed example of the mobile data acquisition system and data transfer alternatives feasible in the system; and Fig. 3 is a flow chart presenting generally the method according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

A mobile data acquisition system of Fig. 1 comprises a central unit 1 and terminals Ll, L2, L3, ... , Ln by which data is gathered e.g. by reading tags Tl, T2, ... , Tn and reporting the data obtained from the tags to the central unit 1 and further on to a data acquisition and service system 5 (Fig. 2) which utilizes said data. The data acquisition system may be e.g. a work management system in which data is gathered from the tags at the work sites by the terminals used by the workers and possibly other information is combined with said read data. The information to be reported may include identification data of the work sites, arrival and departure times connected to them, and information about needs for replacement of materials and accessories or maintenance actions. Some pieces of information are necessary to be reported to the central unit immediately or with a short delay, while some other information may be gathered in the terminal and reported later at a suitable time. The terminal also receives control data from the central unit according to need and in some cases also instructions or other information for the user. The invention concerns data transfer between the terminal and the central unit in one or more mobile data acquisition systems in which both the central unit and the terminal are provided with means and functions for transferring data by means of several alternative data transfer services, e.g. those mentioned above as the background of the invention is considered. In a preferred application, the parts of the terminal responsible for mobile communication are activated for data transfer for only essentially short data transfer sessions in the purpose of minimizing current consumption, and said parts are for the most of the time, e.g. 98 percent or even more, in a deep rest state and completely passive. Besides that, the terminals are also controlled in the preferred application by individual control data sent to the terminals during the data transfer sessions, which control data for example sets the times at which the terminal must wake up the parts responsible for communication for a data transfer session.

Fig. 2 presents an example of data transfer methods and services by which data may be transferred between the terminal Ln and the central unit 1. Two partly overlapping mobile communication networks are available: a GSM network 1 and a GPRS network 2. Additionally, the Internet 9 is available. The central unit 1 obtains management, control and other data from a data base 4 and transmits the data gathered from the terminals to the data acquisition and service system 5.

The central unit 1 comprises a unit 6 which takes care of the data transfer and which is through a connection E directly connected to the Internet 9 and to an e-mail box 10 located there. The unit 6 comprises additionally GSM and GPRS modems. The GSM network comprises in a conventional way also a message center 8 which takes care of transmission of text messages, for example.

Respectively, the terminal Ln comprises a terminal 7 operating in both the GSM and the GPRS networks and comprising components and programs necessary in this application. Data may be transferred between the terminal Ln and the central unit 1 through four alternative ways A, B, C and D. In the alternative A, a direct data transfer connection is established from the terminal Ln through the GPRS network 3 to the central unit 1. In the alternative B, data is sent through the GPRS network 3 as e-mail to the e-mail box 10 from which it is transmitted in a conventional way through the Internet connection E to the central unit 1. In the alternative C, data is sent to the central unit as a text message which is saved in the message center 8 of the GSM network from which the GSM modem of the central unit collects it in a conventional way (connection Cl) or from which it is transmitted forward as an e-mail to the e-mail box 10 of the central unit (connection C2). In the alternative D, a direct data transfer connection is established in the GSM network from the GSM modem of the terminal to the GSM modem of the central unit. In the following, some examples are presented about controlling the terminals in the method according to the invention.

Several data transfer operation modes may be defined for the terminal, e.g. INSTANT, PACKET, DAILY and WEEKLY. The central unit gives to the terminal instructions about the use of data transfer alternatives in each operation mode. The instructions are updated according to e.g. the availability of the data transfer alternatives and services, changes of the rates, and the information obtained about the use, like information about the duration and cost of the sessions. Instructions differing from each other may be given to the terminals about the use of the data transfer modes. E.g. the instruction to work all the time in the mode INSTANT may be given to a terminal used by a new worker, the doings of whom are wished to be followed more accurately in the beginning. Also the instruction to work during certain periods of time, e.g. during a day or a week, in certain operation modes may be given. An alternative is also that the read data determines the mode by which it is transmitted forward from the terminal. A part of the data would then be transmitted forward immediately, another part would be brought to a buffer memory of the mode PACKET and still another part to memories which gather information to be reported either daily or weekly.

Accordingly, the purpose of the operation mode INSTANT is that the information created, e.g. the data read from a tag, is transmitted immediately to the central unit. Therefore, a data transfer session is started within e.g. 1 to 2 minutes from the generation of the information. Because data is sent in this mode often, such an instruction is given to the terminal about the use of the data transfer alternatives by which the aim is to minimize both the duration and the costs of the data transfer sessions. The instruction to the terminal would be, for example, that during a short period of time the terminal tries to send the data as e- mail by the alternative B, and if it does not succeed, then sends the data as an SMS text message by the alternative C. Thus, the object is to send the information by using a lower cost transfer way for minimizing the costs, and if that does not succeed, the transfer of the data and saving in current consumption are ensured by that the information is sent through another transfer way during the same session. The instruction takes then into account also the operational surroundings of the terminal. If the terminal is moving in an area in which the GPRS network is available mostly but not everywhere, then this kind of instruction ensures that the information is in every case sent during the concerned short data transfer session.

In the mode PACKET, an in view of data transfer advantageous amount of produced information is gathered in the buffer memory. As the buffer is filled, a data transfer session is started and the information is sent. The size of the buffer memory may be e.g. 1024 bits which corresponds to the maximum size of the SMS message. As the amount of data in the buffer memory would exceed that amount when adding new data, the buffer is cleared before adding said data and the data cleared from the buffer is sent as a text message according to the alternative C.

In the operation modes DAILY and WEEKLY, the gathered larger amount of data is sent either daily or weekly. Because there is more data to be transferred at a time, the selection of the data transfer alternative is based in this order on assurance, costs and current consumption.

The instruction for the device working in the operation mode DAILY or WEEKLY may be, for example:

1. Send the data at 3:00 in the morning as e-mail, i.e. by using the alternative B. 2A. If 1 does not succeed and the amount of data is not more than four SMS messages, i.e. 4 x 1024 bits, then send the data during the same session as an SMS message, i.e. by using the alternative C. 2B. If 1 does not succeed and the amount of data is more than four SMS messages, then close the session and try to send the data after an hour as e-mail, i.e. by using the alternative B. 3. If 2B does not succeed, then establish a data transfer connection in the GPRS network, i.e. use the alternative A. 4. If 3 does not succeed, then send the data during the same session as an SMS message, i.e. using the alternative C.

In the above example, data is transferred during such a time of day when the operator offers the most advantageous rates and the load of the central unit is minimal. The transfer costs are minimized by trying to use the most advantageous way of transfer another time if the amount of data is large. If, on the contrary, the amount of data is smaller, the current consumption is minimized and real-time properties are improved by sending the data during the same session with reasonable costs.

If the purpose is to receive data from the central unit at the same time, the instruction may be that the terminal tries to establish a GPRS data connection for the session, i.e. tries to use the alternative A, and if that does not succeed during a certain short time the terminal returns to the rest state and starts the session again after certain time through the GSM network, whereby data may be exchanged by using the alternative C. The central unit, finding that the session did not succeed through the GPRS network, has then sent its own data as a text message to the message center of the GSM network and the terminal can deliver its own data to the central unit through the same way.

One primary basis in giving control data to the terminals is the economical advantage of the use of the data transfer alternatives. Many factors affect that. It may be possible to utilize advantageous data transfer rates which the operators offer mainly to the users of mobile phones. Besides that, it may be possible to make a separate contract with one or more operators about the data transfer in the system and the services used for it. Furthermore, it is possible that the operators develop new technical alternatives for mobile data transfer, which alternatives are also economically more advantageous than the earlier ones.

The invention may vary within the scope of the accompanying claims.

Claims

1. Method of transferring data between a terminal and a central unit in a mobile data acquisition system, which comprises: a central unit (1) and several terminals (Ll, ..., Ln) and in both the central unit and terminals corresponding means and functions (6, 7) for transferring data through one or more mobile telecommunication networks (2, 3) by using several alternative data transfer methods and services (A, B, C, Cl, C2, D), and in which method a terminal (Ln) is activated for data transfer for essentially short data transfer sessions in the purpose of minimizing current consumption, characterized in that the use of alternative data transfer methods and services during the data transfer sessions is controlled in the terminal (Ln) by individual control data sent to the terminal by the central unit (1), whereby the control is based at least on minimizing the data transfer costs in addition to minimizing current consumption.

2. Method according to claim 1, characterized in that the control is additionally based on ensuring the success of the data transfer.

3. Method according to claim 1, characterized in that a general instruction is given to the terminal (Ln) about the use of data transfer methods and services during data transfer sessions.

4. Method according to claim 1, characterized in that a special instruction about the use of data transfer methods and services is given for a certain data transfer session or data transfer sessions belonging to a certain class (INSTANT, PACKET, DAILY, WEEKLY).