DE10337054B4 - A method and system for tracking cell switching operations of mobile terminals within a cellular communication network - Google Patents

Abstract

Method for tracking cell change processes of mobile terminal devices (13) within a cellular communication network (10), wherein each cell (11) is assigned a base station (12) with which the active or in a cell located in the cell (11) Mobile terminal devices (13) located in stand-by mode are at least temporarily connected, specific data (20) of the mobile terminal devices (13) being transmitted, and a connection being set up to the base station of the respective mobile station (13) when the cell changes Entry cell takes place, specific data (20) of the mobile terminal devices (13) being transmitted again, characterized in that the tracking of cell change processes takes place anonymously, so that comparative data (22) are generated electronically from the specific data (20) by anonymizing the specific data and / or by extracting such data from the transmitted specific data (20) sfiltered that do not allow a direct assignment to the respective mobile terminal device (13), that encryption data are used as comparison data (22), that the comparison data (22) are electronically ...

Description

The present invention firstly relates to a method for tracking cell switching operations of mobile terminals within a cellular communication network according to the preamble of claim 1. Furthermore, the invention relates to a corresponding system for tracking cell switching operations of mobile terminals within a cellular communication network.

Cellular communication networks are known, for example, in the form of cellular mobile networks. A known mobile radio network is the so-called GSM network (Global Systems for Mobile Communications). In a mobile radio network, the geographical area is subdivided into a number of cells, each cell being assigned a base station, a so-called base station. The individual base stations are connected via so-called "Base Station Controller (BSC)" with mobile switching centers, the so-called "Mobile Switching Centers (MSC)".

If the mobile terminals of such a mobile network, which are then in particular mobile phones, are active, which means that a call is in progress, or if the mobile phones are in a stand-by mode (the devices are turned on, but it is not on the phone) are transmitted by the mobile phones, at least temporarily specific data to that base station in the cell, the mobile phones are currently. In a cell switching process (also called a handover process) in which the mobile moves from one cell to a next, adjacent cell, a connection is established between the mobile and the next cell, in which case it will is an entry cell, generated. In turn, specific data of the mobile phones are transmitted to the base station of this next cell.

In a mobile network, it is thus always known in which cell a mobile phone is currently located. From this procedure, methods have already become known as to how such a handover process can be used for the creation of particular services.

A solution known in this regard for generating information data based on specific data of mobile terminals generated in a cellular communication network is disclosed, for example, in US Pat DE 101 49 943 A1 described. In this solution, specific data of at least one mobile terminal device is detected and processed in a central computer unit. In this way, information data relating to at least one cell of the communication network can be generated. In this known method, the travel time of at least one mobile terminal is determined between a starting point and a spatially separated end point. For this purpose, the specific data of at least one mobile terminal located at the starting point and at the end point is determined and in each case linked to a time stamp. The specific information of the mobile terminal devices are compared electronically in at least one central computer unit. If the specific data of a mobile terminal at the starting point and at the end point match, the time difference between the time stamps is electronically formed in the central computer unit and the travel time determined therefrom. In this way, the travel time of the mobile terminal can be determined without requiring a special infrastructure would be required.

In this known method, however, such specific data of a mobile terminal are used, which allow a clear characterization of the same. Of course, it can then also be deduced from these data where the user of the terminal device is currently located. In some cases, this could be problematic in terms of privacy.

From the DE 196 38 070 A1 a method is known in which the movement of a particular mobile terminal is followed by a communication network. It is in the known Ve4rfahren about reconstructing the locomotion using a map and at the same time to measure the speed. When the mobile terminal performs a cell change in the known method, the corresponding transition time is recorded. The DE 199 48 877 A1 describes a method for the detection of traffic data by means of localization data, wherein the location of certain mobile stations is carried out regularly.

In principle, it is also already known in the prior art that data of a subscriber in a mobile radio communication network can be anonymized for reasons of data protection. In the essay "Federrath, Jerichow, Kedogan, Pfitzmann, Spaniol - mobile communication without motion profiles - Günther Müller, Andreas Pfitzmann (ed): Mehrseitige Sicherheit in Kommunikationstechnik, Addison-Wesley-Longman 1997, pages 169 to 180" is described that it is possible to prevent the tracking of mobile stations of a subscriber in the communication network for data protection reasons, for example by a pseudonymization of the participants in the network.

The DE 195 45 248 A1 discloses a method for the anonymous use of a communication system wherein, in addition to access identifiers, further group identifiers are assigned which are transmitted with and prevent handover of access identifiers.

The present invention is therefore based on the object, a method of the type mentioned in such a way that in a simple and inexpensive way cell exchange operations (handover operations) mobile terminal devices can be tracked within a cellular communication network, without causing an assignment to the mobile terminal devices takes place. Furthermore, a correspondingly improved system should be provided.

This object is achieved by the method with the features of independent claim 12. Further advantages, aspects and effects of the invention will become apparent from the features, details, aspects and effects of the invention will become apparent from the dependent claims, the description and the drawings. Details which are described in connection with the method according to the invention, of course, also apply in connection with the system according to the invention and in each case vice versa.

The present invention is based on the finding that the tracking of the cell change processes now takes place anonymously.

According to the first aspect of the invention, there is provided a method of tracking cell switching operations of mobile terminals within a cellular communication network, each cell being associated with a base station with which the cell is in active or stand-by mode mobile terminal devices are at least temporarily in communication, wherein specific data of the mobile terminal devices are transmitted and wherein a cell exchange of a mobile terminal connection to the base station of the respective entry cell is carried out, in turn, specific data of the mobile terminals are transmitted. The method according to the invention is characterized in that the tracking of cell change processes is anonymized, that for this purpose electronic comparison data are generated from the specific data, in which the specific data is anonymized and / or filtered out in the specific data transmitted from the data be allowed, which do not allow direct assignment to the respective mobile terminal, that as comparison data encryption data are used, that the comparison data are electronically linked respectively with a timestamp and specific cell data and processed in a computer unit, that in the computer unit all comparative data are continuously compared, that, in the case of a match of comparison data, the associated time stamps and / or cell data are compared with one another, and that from the determined comparison values, information data about a cell change process of the corresponding comp calibration data are generated.

With the method according to the invention, in particular a simple handover tracking of mobile terminals is made possible. At the same time, the requirements of adequate data protection are taken into account.

Namely, a basic idea of the present invention is that, from the specific data of a mobile terminal, from which a cell switching process is basically apparent, comparison data in such a form is now generated, which are detached from the mobile terminal. This means that it is not easy to draw a conclusion from the comparison data to the corresponding terminal device and thus to its user.

In the method according to the invention, the cell change process of this comparison data is now tracked. Thus, a misuse of the data is no longer possible.

First, it is provided that the method is carried out in a cellular communication network. However, the invention is not limited to certain types of cellular communication networks. However, the method can be carried out particularly advantageously using a cellular mobile radio network, in which case the mobile terminals are designed as mobile telephones, the comparison data being determined from specific data of the mobile telephones. The invention is not limited to certain types of mobile terminals. For example, the mobile terminal devices can be mobile computers, PDAs (Personal Digital Assistants), in the case of a mobile radio network, mobile telephones or the like.

The specific data transmitted from the mobile terminals to the base stations, which serve as a basis for the generation of the comparison data, may be, for example, those data which occur during operation of the mobile terminals anyway. This may be, for example, data relating to the movement of the mobile terminals, such as between different cells (handover between cells) and / or within a cell, the time-dependent and / or local Distribution of mobile terminals, the call set-up rate and / or rate of degradation, and the like.

If the method is operated in the context of a cellular mobile radio network, it is in principle possible to utilize as specific data of the terminal devices designed in this case as a mobile telephone, data which arises within the framework of the basic functioning of the mobile radio network. In addition to the data types mentioned above, this also includes real-time and cell activity data from active mobile terminals. These are received by the respective base stations and usually forwarded via the BSCs and MSCs for further processing, archiving and the like. It is not absolutely necessary that just a telephone call should be made using the mobile phones to collect specific data. Rather, it is sufficient if a mobile phone is in a stand-by mode, that is, when it is only turned on. In such a case, the mobile phone periodically transmits so-called registration signals, which are then detected by nearby base stations. This is a basic operation of a cellular mobile network.

So that the tracking of cell change processes can take place anonymously, it is initially provided that comparison data are generated electronically from the specific data of a mobile terminal device. The comparative data, which form the basis for the further procedure, should not allow any direct inference to the terminal sending the data. This can be done in different ways. For example, it is conceivable that the specific data itself will be anonymized. In addition or in another embodiment, it is conceivable that certain data which does not permit direct assignment to the respectively mobile terminal device are filtered out of the transmitted specific data. Tracking cell-change operations will then only consider this particular data. Of course, other approaches are possible in principle, as comparison data could be generated from the specific data.

The generated comparison data are electronically linked to a timestamp and specific cell data. In this way, it becomes possible in a particularly simple manner to generate information data extending over greater distances. The comparative data supplemented in this way with time information and position information are then processed in a computer unit. In the computer unit, therefore, all the comparison data of all active or in stand-by mode terminal equipment, which are located in any cell of the communication network together.

In the computer unit all incoming comparative data are continuously compared. As soon as a match of comparison data is determined, the associated time stamps and / or the cell data are compared with one another within the computer unit.

Information data about a cell change process of the corresponding comparison data can then be generated from the comparison values determined therefrom.

The method according to the invention is therefore a very simple and anonymized method for the cell exchange tracking of a mobile terminal device, for example a mobile telephone. Since this method requires no high memory resources and the corresponding computer units are hardly loaded, it can be integrated as an extension in the respective software of the BSC's (Base Station Controller). Additional hardware components are not needed in this case.

Statistical evaluations can also be carried out particularly well with the aid of the method according to the invention.

Advantageously, it can be provided that end device-independent data are used as comparison data, which have no concrete relation to the mobile terminals, and which remain constant in the active or stand-by mode of the terminals and at each cell change a mobile terminal when establishing a connection with the associated base station be retransmitted. According to the invention, the comparison data are encryption data, in particular "encryption keys". In general, all data that is needed to encrypt or decrypt data can be considered as encryption data. In particular, these data may be the corresponding keys, which may be embodied as symmetrical or asymmetrical keys, for example.

By using "Encryption Keys" can be ensured in a particularly simple manner that an identification of a mobile terminal that transmits such an "Encryption Key" occurs without misuse of the data is possible. In addition, the uncertainty that the same "encryption key" will be awarded a second time is extremely low.

This will be briefly explained by means of a non-exclusive example. If the procedure is performed using a cellular mobile network, this is performed primarily at active terminals. At the beginning of a conversation, an "encryption key" is determined, which is maintained throughout the conversation. A new conversation also assigns a new "encryption key".

An active mobile phone is not tracked for its TMSI (Temporary Mobile Subscribed Identity) during a call, but for the "Encryption Key". This key remains constant during a telephone call and is retransmitted each time the handover is established. Simply by evaluating the connection setup packets or parts of these data packets, a mobile phone movement can be tracked.

The information data generated in the process can be further utilized in different ways. Thus, it is conceivable, for example, that the method determines the travel time and / or the speed of movement of terminal equipment through one or more cells of the communications network. It is likewise possible for traffic information to be generated with the method according to the invention. However, the invention is not limited to certain types of traffic information. For example, it is possible to generate traffic information that reflects the current traffic situation on roads. The procedure can also be used as a navigation aid or as a statistical basis for transport planning - for example, by public authorities.

Apart from the generation of traffic information data, it is also possible with the method according to the invention to generate information data in connection with location-based services (LBS) or the like. In the case of a location-based service, first the position of a terminal for which this service is offered is determined. On the basis of these position data, site-specific services are then offered, location-specific interactions are carried out between terminals and other facilities, and the like.

The specific cell data may be, for example, cell identification data, cell size data, or the like.

The generation of the comparison data can be done in different ways. It is thus conceivable, for example, for the comparison data to be generated in the mobile terminal itself and to be linked therein with a time stamp and / or with specific cell data. These data are then transferred to the computer unit, where they are evaluated and further processed. In another embodiment, it may also be provided that the comparison data of a mobile terminal device is first transmitted to the computer unit or else first generated in this computer unit. In the latter case, specific data is transmitted from the mobile terminal device to the computer unit, in which comparison data are then generated in the manner described above. The comparison data are then linked in the computer unit with a time stamp and / or with specific cell data and further processed in the intended manner or further processed.

Advantageously, identical comparison data as well as the respectively associated time stamps and / or specific cell data can be linked to a history file and at least temporarily stored in a memory device. The generation of such history files is particularly advantageous if statistical evaluations, long-term evaluations and the like are to be carried out with the method, for example, if the method is intended to create a statistical basis for traffic planning.

Advantageously, information data relating to two or more cells of the communication network can be generated, wherein at least some of these cells can be formed directly adjacent or spatially separated from each other in the communication network. In this regard, it may be provided, for example, that comparison data of terminal devices are generated within two or more cells and compared with one another in the computer unit. If at least components of comparative data of terminal devices in different cells match, the time difference between the respective time stamps can then be electronically determined in the computer unit and the travel time of the terminal devices determined therefrom.

This will be illustrated by a non-exclusive example. If the travel time of at least one mobile terminal between two cells, for example between a starting point A and a spatially separated end point E, is to be determined first, in a first step. Comparison data determined at least one located at the starting point A mobile terminal and each associated with a corresponding timestamp ZA and with specific cell data. In this way, it can be determined that the mobile terminal has been located at a point in time A corresponding to the timestamp ZA at the starting point A located in a certain cell.

In the same way, comparison data of this mobile terminal device located at the specified end point E are determined and in each case linked to a time stamp ZE and specific cell data. In this way it can be determined that a mobile terminal has been located at the end point E at a certain point in time which corresponds to the time stamp ZE.

The data of the at least one mobile terminal located at the starting point A and at the end point E determined in this way are electronically compared with one another in the at least one computer unit. In this way, it is checked whether the respective comparison data, and thus ultimately the associated mobile terminal devices - but anonymous - match. If the comparison data of a mobile terminal match at the starting point A and the end point E, this means that one and the same mobile terminal was located both at the starting point A and at the end point E. If such a match is detected, the time difference ZE-ZA between the timestamps is formed electronically in the computer unit. From the resulting time difference, the travel time of the mobile terminal between the starting point A and the spatially separated end point E is then determined.

According to the second aspect of the invention there is provided a system for tracking cell switching operations of mobile terminals within a cellular communication network, the system being characterized according to the invention by means for performing the method according to the invention as described above. In particular, the communication network may be formed as a cellular mobile network, wherein the terminal devices are designed as mobile phones.

The invention will now be explained in more detail using an exemplary embodiment with reference to the accompanying drawings. In the single figure, a system according to the invention for tracking cell change processes of mobile terminals is shown, by means of which the method according to the invention can be carried out.

In the figure is designed as a cellular network cellular communication network 10 represented, its geographical area in a number of cells 11 is divided. Each of these cells 11 is a base station 12 assigned. A mobile terminal device 13 , in the present case a mobile phone, communicates in its active state (a call is in progress) or in a stand-by mode (the device is switched on, but no call is made) at least temporarily with the base station associated with the cell in which is the mobile phone 13 currently located.

If now the mobile phone 13 Moving from one cell to another cell (handover) finds a connection between the mobile phone 13 and the base station of that cell instead, into which the mobile phone 13 entry. When communicating between mobile phone 13 and base station 12 Be specific data of the mobile phone 13 transmitted by which the mobile phone 13 can be characterized.

In a car congestion determination, by means of the GSM (mobile radio) data analysis, a method is known to track a call over several cells (for example along a highway) and to determine the traffic speed from the cell change processes. In doing so, the call must be tracked over all cells where the cellphone could go. Furthermore, all associated data packages must be recorded, which would mean a very high cost in the software and hardware. Furthermore, such a process could raise privacy concerns, as from the mobile phone 13 transmitted specific data always also clear conclusions on the specific mobile phone 13 and thus its users are possible.

The method according to the invention makes an anonymous tracking of cell change processes possible. For this purpose, according to the example shown from the specific data of the mobile phone 13 electronic comparison data 22 generated by filtering out of the specific data such data, which is not directly associated with the respective mobile phone 13 allow. In the present example, this takes place in a computer unit designed as an evaluation device 16 ,

In the present example, it should be in the comparative data 22 to encrypt data, in particular the "Encryption Key" act on one of the mobile phone 13 the call made is not changed and is retransmitted each time a connection is established to the respective cell. For this it is envisaged that from the recording of specific data 20 (eg the Abis data) between the base stations 12 and Base Station Controllers (BSC) 14 from the handover CHNAV packages (Chanel Activation Packages) 21 read out the "encryption key" and together with the current time (timestamps 23 ) and cell identification data (specific cell data 24 ) to the computer unit 16 is transmitted. For this purpose, the base station controllers 14 apart from their actual connection to the Mobile Switching Centers (MSC) 15 also with at least one computer unit 16 , which in the present case acts as an evaluation unit connected.

In the computer unit 16 become the comparative data 22 along with the timestamps 23 and the specific cell data 24 to history files 25 linked and at least temporarily in one of the computer unit 16 associated memory device 17 stored. In addition, the individual data and files can also be stored on one of the computer units 16 associated display device 18 be visualized.

When there are time stamps 23 for two or more cells 11 for one and the same set of comparative data 22 , For example, an "encryption key" can be determined from the time difference, the time that the comparison data 22 , needed to cross one or more cells. By using the "Encryption Key" to identify an ongoing call, data misuse is not possible because it is not directly related to the mobile phone 13 consists.

By means of the method according to the invention, it is now possible to track a call over a plurality of cells (even if incompletely) with a very low outlay. Only the connection setup CHNAV in the relevant cells has to be evaluated.

LIST OF REFERENCE NUMBERS

10

cellular communication network (mobile network)

11

cell

12

base station

13

mobile terminal device (mobile phone)

14

Base Station Controller (BSC)

15

Mobile Switching Center (MSC)

16

computer unit

17

memory device

18

display

20

specific data (Abis data)

21

specific data (handover data)

22

Comparison Data (Encryption Keys)

23

timestamp

24

specific cell data

25

history file

Claims (13)

Method for tracking cell switching operations of mobile terminals ( 13 ) within a cellular communication network ( 10 ), each cell ( 11 ) a base station ( 12 ) with which in the cell ( 11 active or in a stand-by mode mobile terminal equipment ( 13 ) are at least intermittently linked to specific data ( 20 ) of the mobile terminals ( 13 ) and wherein when a cell change of a mobile terminal ( 13 ) a connection is established to the base station of the respective entry cell, whereby in turn specific data ( 20 ) of the mobile terminals ( 13 ), characterized in that the tracking of cell change processes takes place anonymously, that from the specific data ( 20 ) electronic comparison data ( 22 ) by anonymising the specific data and / or by extracting from the transmitted specific data ( 20 ) that filters out data that is not directly attributed to the respective mobile terminal ( 13 ) allow, as comparative data ( 22 ) Encryption data are used that the comparison data ( 22 ) electronically each with a timestamp ( 23 ) and specific cell data ( 24 ) and in a computer unit ( 16 ), that in the computer unit ( 16 ) all comparative data ( 22 ) are compared with each other in such a way that if the comparison data ( 22 ) the associated time stamps ( 23 ) and / or the cell data ( 24 ) and that from the determined comparison values, information data about a cell change process of the corresponding comparison data ( 22 ) be generated. Method according to claim 1, characterized in that as comparative data ( 22 ) end-device-independent data that has no concrete reference to the mobile terminal equipment ( 13 ) and in the active or stand-by mode of the terminals ( 13 ) remain constant and at each cell change of a mobile terminal ( 13 ) when establishing a connection with the associated base station ( 12 ) are retransmitted. Method according to claim 1 or 2, characterized in that as comparative data ( 22 ) "Encryption Keys" are used. Method according to one of Claims 1 to 3, characterized in that it is carried out using a cellular mobile radio network, the mobile terminals ( 13 ) are designed as mobile phones. Method according to one of claims 1 to 4, characterized in that so that the travel time and / or the speed of movement of terminal equipment ( 13 ) by one or more cell (s) ( 11 ) of the communication network ( 10 ) is determined. Method according to one of claims 1 to 5, characterized in that it generates traffic information. Method according to one of claims 1 to 6, characterized in that it generates information data in connection with location-based services. Method according to one of claims 1 to 7, characterized in that it is in the specific cell data ( 24 ) is cell identification data and / or cell size data. Method according to one of claims 1 to 8, characterized in that the comparison data ( 22 ) in the mobile terminal ( 13 ) and in the mobile terminal ( 13 ) with a timestamp ( 23 ) and / or with specific cell data ( 24 ), and that this data is subsequently transferred to the computer unit ( 16 ) be transmitted. Method according to one of claims 1 to 8, characterized in that the comparison data ( 22 ) a mobile terminal ( 13 ) to the computer unit ( 16 ) or in the computer unit ( 16 ) and that the comparison data ( 22 ) in the computer unit ( 16 ) with a timestamp ( 23 ) and / or with specific cell data ( 24 ). Method according to one of claims 1 to 10, characterized in that identical comparison data ( 22 ) as well as the associated time stamps ( 23 ) and / or specific cell data ( 24 ) to a history file ( 25 ) and at least temporarily stored in a memory device ( 17 ) are stored. System for tracking cell switching operations of mobile terminals ( 13 ) within a cellular communication network ( 10 ), characterized by means for carrying out the method according to one of claims 1 to 11. System according to claim 12, characterized in that the communication network ( 10 ) is designed as a cellular mobile radio network and that the terminal equipment ( 13 ) are designed as mobile phones.

Images