AT502073B1 - METHOD AND SYSTEM FOR OBTAINING TRAFFIC FLOW INFORMATION - Google Patents

Abstract

Method for obtaining traffic-flow data in which position data and identification of mobile terminal (MS) in at least one vehicle is obtained. The position data is obtained from the signaling data during entry of the respective vehicle into a new cell-zone (LA;LA B) with establishing of the identification of the first cell (Z B1) in the new cell zone. The signalling data is taken off at the interface (A) between the RF switching station (MSC) and the associated base station controllers (BSC). An independent claim is also included for a system for obtaining traffic flow information.

Description

2 AT 502 073 B1

The invention relates to a method for obtaining traffic flow information in which position data including an identifier of at least one mobile terminal device carried in a vehicle is obtained from signaling data between base stations and at least one central exchange of a cellular network with cells combined in cell 5 areas are combined, this position data with time stamp data, and assigned to this combined position data map data, with which they are processed to obtain the traffic flow information. io Furthermore, the invention relates to a system for obtaining traffic flow information, in which for obtaining position data including an identifier of at least one in a vehicle carried on, powered mobile terminal from signaling data between base stations and at least one central mobile switching center of a cellular network with Cell areas are arranged probes 15 at the connections between the base stations and the central office and a monitoring unit is connected to the probes to detect signaling data that are fed to an analysis unit, which are further associated database means for map data. From DE 100 32 800 A1 a method for detecting traffic situation data is known, wherein a cellular mobile radio network is used, which contains a plurality of uniquely identified base stations and thus cells that cover the traffic route network considered; in this traffic network are vehicles in which the mobile network belonging mobile devices are available. If a vehicle with a mobile terminal located therein is considered, the travel of this vehicle is tracked on the basis of the identification of the base stations or cells, whereby the route identification in the traffic route network is determined via these cell identifications. One problem with this, however, is that only actively used mobile terminals are detected via the base stations, ie mobile phones that are not only turned on but are also actively involved in communication with another subscriber. This does not include those mobile devices that are on but are not currently being actively used. Research has shown, however, that only a fraction of mobile terminals in vehicles, namely about 2-5%, are actively in operation; but only very vague statements about the traffic situation can be made. 35

A further disadvantage is that in the area of the base stations or the Abis interfaces associated with these base stations, there are no standardized electronic devices, but devices having different standards depending on the manufacturer in use. As a result, there are problems with the data acquisition in this area of the A 1 interfaces because, apart from the fact that the respective approval of the network operator is required, also adaptations of the probes depending on the type of device are required.

A particularly serious disadvantage is that there are a plurality of base stations and, accordingly, there are the same number of Abis connections that need to be monitored by means of probes. This not only means that a corresponding large number of probes must be installed for data acquisition, but also that an extremely large amount of data has to be acquired and probed, whereby it should also be taken into consideration that the entire signaling traffic is handled via the Abis interfaces and therefore an extremely large number of signaling needs to be processed per subscription connection.

Furthermore, it is disadvantageous that, as studies have shown, an average call duration is approximately two minutes, which corresponds to a distance of 4 km in the case of a vehicle moving on a highway at a speed of 120 km / h. Accordingly, an active participant, i. an active mobile terminal, an average of only 4 km 3 AT 502 073 B1 long (eg on a highway) to be tracked, which is the evaluation and extraction of information about a traffic happening in larger traffic network areas, such as on a motorway route with a length of 50 or 100 km, additionally difficult. The above drawbacks equally apply to the method and system for determining the travel time of a mobile user terminal according to DE 101 49 943 A1, since also there the determination of the positions of the terminal devices (ie terminals) is limited to actively used terminals , Whereby the necessary information about the base stations, thus in turn on the Abis connections won. 10

According to DE 103 34 140 A, a cellular position determination also takes place in the determination of traffic data described therein, wherein the change of an active terminal from one mobile radio cell to the next is detected in detail, and wherein in the transition area a road section is assigned, so that a virtual Counter for the changing of the one cell from one cell to the other vehicles (but only for those vehicles in which an actively operated mobile phone is located) is created. These counts are then used to estimate the traffic volume, and it is also envisaged to exclude public means of transport (i.e., active terminals located more precisely in public transport) from this traffic count by filtering out the corresponding data. 20

Also in the article by Jean-Gabriel Remy, "Computing messages: the STRIP project", 2001 IEEE Intelligent Transportation Systems Conference Procurement - Oakland (CA), USA - August 25-29, 2001, pages 6 -9, a system for estimating travel times based on radiotelephone signaling data is addressed, with 25 in turn being based on active, ie involved in a conversation radiotelephone devices. Although it is also referred to merely switched, non-active terminals, but only with the note that the position determination here, although possible in principle, would be so cumbersome. On the other hand, it is stated that 5% of the vehicles (namely, apparently those with active mobile telephones) would be sufficient to estimate driving times. It is further emphasized that the inclusion of position data must not influence the load on the radio network. Another disadvantage, however, is that in the case of the specifically described embodiment in the mobile telephone network, the data is to be recorded at the Abis interfaces (that is to say the interfaces between the base stations and the associated base station controllers), which is the disadvantage of the huge amounts of data to be processed. the need for the many probes, the manufacturer-dependent interface devices and thus the adaptation of the probes to the latter brings.

Finally, DE 102 37 563 A1 describes a technology for determining location data of 40 moving objects, in which the location data are determined either by means of GPS and forwarded by means of a mobile terminal or else by the base stations of mobile radio cells to an exchange. Here, too, at least the disadvantages explained above result. It is an object of the invention to provide a method and a system as stated above, wherein from the outset less data for the extraction by traffic flow information are to be included, further with a much smaller number of probes Auslangen can be found and also the installation the required facilities is simplified. Furthermore, in the technique according to the invention, all subscribers, i. E. mobile terminals, which are traveling with a mobile terminal switched on, without an active call connection is necessary for the detection, i. without the mobile terminal having to be actively used.

The invention is based on the recognition that position data can be used for obtaining the position data and 55 for the derivation of the traffic flow information, not only between base stations and base station controllers, but also between the latter and the or be transmitted to the central mobile switching centers. These position data are update data, in the case of a GSM network in particular the "Location Updates", in the case of GPRS the "Routing Area Updates" and in the case of a 5 UMTS network the "Location / Routing / UTRAN Area Updates". These update data are respectively available when changing from one cell area (in GSM networks "Location Area", in GPRS "Routing Area", and in UMTS "UTRAN Area") into a subsequent cell area, i. in such a change of the cell area, the aforementioned localization update takes place, wherein in each case the identification of the first cell of the new io cell area is also transmitted. This is exploited in the technique according to the invention, so that an exact position - with the resolution of a cell - is made possible on entry into the respective new cell area without an active call signaling being necessary for this purpose. Accordingly, the invention provides a method and a system according to the appended independent claims in order to achieve the above object. Advantageous embodiments and further developments are specified in the respective dependent claims.

According to the invention is thus at the one or more central exchanges (MSC -20 Mobile Switching Center), thus at the A-interface in the case of a GSM network or the Gb interface in the GPRS case and at the lu interface in the case UMTS network, the detection of the signaling data made. By detecting the position of the respective vehicle with mobile terminal turned on with cell accuracy, even if only entering a new cell area, the technique according to the invention achieves cell positioning accuracy, comparable to prior art systems. Compared to the prior art, however, the considerable advantage is achieved that a much smaller amount of data has to be captured and processed, and that also fewer probes have to be installed in order to acquire the desired signaling data, the reduction corresponding to the fact that instead the cells are now monitored each containing a plurality of cell cell areas (or more precisely the connections from their base station controllers to the associated central mobile switching center). It is therefore not the number of cells themselves, but the number of cell areas that determines the number of probes, and, moreover, only the respective position update data (when entering the respective new cells) is relevant. Area) and the processing for the purpose of obtaining the traffic flow information must be supplied. Another advantage is that in the area of the A-interface (or Gb or lu interface) regularly standardized facilities exist, so that no adaptations are necessary when mounting the probes. 40 Thus, the invention provides a considerable apparatus and procedural simplification compared to the prior art, without a loss in the accuracy of the positioning would have to be accepted; Another advantage is that now, unlike the prior art systems, only switched-on, non-actively used mobile phones (mobile terminals) are taken into account so that the reliability of the calculated traffic flow information is substantially increased.

Each recorded event, ie the respective position data with terminal identifier and identification of the respective first cell of the new cell area, is provided with a time stamp, as is known per se, and the geographic coordinates are assigned as known per se. The time for the timestamp data is conveniently taken from an in-house clock, and the geographic coordinates are extracted from database resources and mapped by map matching. It is then easily possible to determine the speeds of all participants or terminals that move through one cell area to the next. If, for example, a particular highway section 55 is monitored, it is possible to reduce the computational effort to take into account only those terminals 5 502 073 B1 which in predefined cells (namely, those corresponding to the desired motorway section) a cell Range limit exceeded, ie it is additionally reduced from the outset, the amount of data to be processed. Then all those terminals can be filtered out, whose speed does not reach a certain minimum value 5 or does not fall within a certain interval, which of course here is to take the prevailing traffic conditions consideration. Furthermore, all public transport subscribers (that is, for example, terminals that are carried on buses) can be excluded, on the basis of comparison with historical data or public transport schedules; On the other hand, public transport can also be excluded directly from the data collected, for example by comparing periodic peaks that arise as a result of public transport or, in particular, if there are identical time stamps for each of the multiple terminals (if they exceed a certain minimum). not in conventional vehicles, but in buses, especially in public transport, be carried. 15

When removing the signaling data in the area of the central mobile switching centers, as mentioned, the signaling data of the candidate "first" cells can be directly selected and the messages from other cells, for example when a terminal is active and therefore messages are continuously transmitted by other cells during cell changes , discarded immediately in order to keep the amount of data very low in this regard. By means of data filtering, the desired position (update) data can be extracted from the signaling data that is acquired, and only these localization update data are recorded or stored for further processing. Furthermore, it is also possible for data processing to subject position data which has only been timestamped at 25 (so that no average speed can be determined by a cell range) to a limited utilization (count). These position data point to vehicles with terminals that have interrupted or stopped their journey in the considered cell area. For the derivation of the respective desired traffic flow information (for example concerning density of traffic, rate of traffic, mean driving speed of the vehicles or number of vehicles at certain times) in data processing, the data used to obtain the traffic flow information may by itself smoothing known data filters. Typical known data filters that can be used here are lowpass-35 filters (in the frequency domain), moving average data filters or Kalman filters.

The probes can be formed by network cards installed in the area of the central exchanges, which have a high-inductance input. In order not to burden the respective mobile radio network or its facilities, the probes and downstream units of the present system are installed independently of the cellular network; In particular, separate, independent computer means and the like are thus provided in order to achieve the desired information acquisition. The invention will be explained below with reference to particularly preferred embodiments, to which it should not be limited, and with reference to the drawings. In the drawing: Fig. 1 shows schematically a part of a cellular network with cells belonging to two cell areas and a traffic route, for the purpose of illustrating the principle of position-related signaling data; Fig. 2 shows schematically the hierarchy of a GSM network; Fig. 3 shows schematically a part of a GSM network with a system for obtaining traffic flow information coupled thereto in accordance with the invention; 4 shows a protocol stack of a position update request; Fig. 5 shows the signaling and messages in a position updating process; 6 shows the formats and the hierarchy (protocol stack) for a POS update request; FIG. 7 shows a diagram of the acquisition of the signaling data in the area of a central mobile switching center with a network card probe, a probe server and a distributed database; FIG. Fig. 8 is a block diagram illustrating data preparation for later analysis; Fig. 8A is a flow chart for illustrating the operation of data processing; Figure 9 is a graph showing the number of 5 detected events (i.e., detected mobile terminals) over time with an additional curve after smoothing the data obtained, on the one hand for the actual traffic flow and on the other hand for the position updates detected in accordance with the invention; and Fig. 10 also shows the position updates taken over one day in a comparison with the actual traffic, wherein in an additional curve the number of io "tracked" mobile terminals moving through several cell areas is illustrated.

In the following, the invention is explained by way of example in connection with a GSM network, but as already indicated, the invention can be used in the same way for other cellular mobile networks in which cells are grouped into logical groups called cell areas in which a subscriber can be "paged" if a call is received for him. These logical groups of cells are called "Location Areas" (LA) in the case of a GSM (Global System for Mobile Communications) network, in the case of a Packet Switching GPRS network (General Packet Radio Service - General Packet Radio Service ) "Routing Areas" (RA), in the case of a UMTS network, a network independent of the GSM network (UMTS - Universal Mobile Telecommunication System - Universal Mobile Radio System) "Location Areas", "Routing Areas" or "UTRAN Registration Areas" (URA). When the telephone number of a mobile station MS, referred to herein as a mobile terminal, is dialed, the call is routed through the telephone network to the appropriate gateway radio exchange from which a connection to the HLR (Home Location Register) is established to check the validity of the number and authorization to use the requested services. The HLR then retrieves the roaming number of the subscriber from the VLR (Visitor Locati-30 on Register), and based on this roaming number, the HLR can then determine which central mobile switching center is currently responsible for the mobile terminal. If the mobile terminal is currently available, which is verified by the central office via the VLR, the mobile services switching center will start broadcasting through all connected cells, called "paging". This broadcast message is sent by the base transceiver station BTS (Base Transceiver Station) of the BSS (Base Station Subsystem).

In order to enable this "paging", all mobile devices, whether they are only switched on or actively used, will enter a new cell area with the help of the so-called Location Updates (LU - general localization updates ), so that the cell area in which the affected mobile terminal is currently located is known. This location update (in general: this position update) is accordingly a mandatory procedure for all mobile devices, and the corresponding messages are generated by the mobile terminal or / and by the central mobile switching center 45 and transmitted transparently between the mobile terminal and the central mobile switching center. (The central mobile switching center is also called MSC - Mobile Switching Center.)

Comparable updates to the localization of mobile devices are available in the case of GPRS (these updates are called RAU - Routing Area Updates) and the UMTS network.

Fig. 1 now schematically shows two location areas (LA) LA A and LA B, each having a number of cells Z, e.g. in each case first cells Z A1 or Z B1 along a traffic route V, for example a freeway, as seen in the direction of travel (see arrow) of a person located in a route AT 502 073 B1

Vehicle along the traffic route V moving mobile terminal MS (MS - Mobile Station) included. In each cell Z, the mobile terminal MS is integrated into the call connection via a base station BTS (see also Fig. 2), and all base stations BTS of a cell area are controlled by 5 and controlled by at least one base station controller BSC. Figure 2. Accordingly, a base station controller BSC defines or multiple base station controllers BSC together define a cell area LA, respectively. (However, for the sake of simplicity, in the examples described below it is assumed that a base station controller BSC defines a cell area LA). According to FIG. 2, the base station controllers BSC are in turn assigned to a common central mobile switching center MSC. In a mobile network then usually several such mobile switching centers MSC are provided and interconnected, s. also FIG. 3. In FIG. 1, for the sake of completeness, a so-called handover procedure is also schematically indicated, which takes place during a cell change during an ongoing conversation, ie when the speaking participant moves across cell boundaries. This "handover" is indicated in the region of the cell boundaries 1 and 2 with thick lines, wherein in the case of the cell boundary 2 at the same time the boundary between the cell areas LA A and LA B is given 20.

Apart from this special handover process, in which the speaking subscriber is passed on, so to speak, from one base station to the next, there are further procedures in a GSM network which deal with the mobility of subscribers in the network. As already mentioned, there must always be the prerequisite that a subscriber can be paged so that this subscriber, who is located somewhere in the network area, can also be called, or with him a message, e.g. a short message (SMS), can be delivered. For this purpose, as mentioned with the help of localization updates from the network, the respective cell area is detected, in which the subscriber enters, so that the current location of the subscriber, ie. a powered-up mobile device (which does not need to be active) with a certain granularity constantly updated. For this position monitoring, the interfaces between the base stations BTS and the respectively associated base stations 35 controllers could be monitored per se - and this was the state of the art so far - in other words the so-called Abis interfaces. From Fig. 2, it is already clear that in a network actually very many such Abis interfaces or connections are to be monitored, with the really interesting position data must be extracted from a plethora of data, so that not only a high apparatus Expense, but also a considerable procedural effort 40 associated with it. In addition, in this area, the hardware components are often designed differently depending on the manufacturer, so that appropriate adaptations are necessary for the data extraction.

The interfaces or connections between the individual base station controllers BSC 45 and the respectively associated central mobile switching centers MSC are called A-interfaces or A-connections, wherein as shown in FIG. 2 immediately apparent compared to the Ab | S interfaces substantially less -Interfaces or A-connections must be present or supervised. As a result, if data is extracted at this point, the effort can be substantially reduced, apart from the advantage that standardized hardware components are usually present at this point, so that no adjustments of the probes for the data acquisition are required. Furthermore, the data can in each case be concentratedly recorded in the area of a central mobile switching center MSC, so that there is also a simplification for the data transmission, for its further processing for the purpose of obtaining traffic flow information. This is apparent from Fig. 2 and also immediately 55 from Fig. 3, where in the area of central mobile switching centers MSC, e.g. 3, several directly connected probes 4 are illustrated in the A connections to the associated base station controllers BSC.

For the sake of completeness, a 5 base station controller BSC with base stations BTS connected via an Abis interface and with a probe 4 assigned to the A connection (BTS - Base Transceiver Station) is shown in detail in the diagram of FIG. ,

The probes 4 transmit the recorded data, namely the usual SS7 messages io (SS7, also SS # 7 - Signaling System No. 7 - Signaling System No. 7, an international telecommunication standard of the ITU) to a monitoring unit 5.

The SS7 messages correspond to a protocol stack with 7 layers, the layers essential here (above the MTP1 to MTP3 layers (MTP - Message Transfer Part -15 message transmission part) the SCCP layer (SCCP - Signaling Connection Control Part signaling connection Control part) and the layers are over it.

The monitoring unit 5, together with a data filter unit 6, belongs to a data processing unit 7, from which the extracted localization update data are stored in a database 8 20 (which may also be a distributed database). In this database 8 accessed by one or more computer means analysis unit 9 accesses, said analysis unit 9 is further connected to another database 10, are stored in the geographical data or coordinates. Finally, traffic flow information obtained with the aid of the analysis unit 9 is output via an output unit 11, e.g. printed or displayed on a display. Of course, as well as the monitoring unit 5, the analysis unit 9 is assigned an input unit (which is not shown in greater detail in FIG. 3), for example to define the respective traffic route V (see FIG. 1) and thus also to determine those probes 4. those responsible for monitoring this traffic route V with regard to it, ie To determine in vehicles entrained mobile terminals MS. Of importance is that, although basically all base station controllers BSC are continuously monitored (can), but that in the event that only very specific traffic routes V are to be examined, only the corresponding probes 4 in the A connections from the respective mobile switching center MSC activated or switched through to the affected BSCs. This can be done, for example, via the monitoring unit 5 by activating or selecting only those inputs to which the probes 4 affected by the given cell areas are activated. This selection can be carried out via a separate input unit on the monitoring unit 5 or also optionally via the analysis unit 9 (or the computer unit 9 realizing this analysis unit), in which case a corresponding connection between this analysis unit 9 and the monitoring unit 5 will be provided. This is indicated schematically in FIG. 3 with a dashed connection 12.

FIG. 4 schematically illustrates a protocol stack of a location updating request. This is the format that exists on the 45 A interface. The information elements of such a localization update request are as follows: Protocol discriminator Cipher key sequence number Sun Type of location update (normal, periodic, attachment to a subscriber identification) Identification (identifier) of the cell area (Location Area Code - LAC) - Class designation of the mobile terminal - Identification of the mobile terminal (TMSI or IMSI) 55 Of these information elements, the following three elements are of interest: Primary the 9 AT 502 073 B1

Identification of the cell area; then the identifier of the subscriber, i. the mobile terminal so as to be able to follow this subscriber; and, moreover, the location update type prefers to filter out the normal location updates from all MM messages (MM mobility management). 5

The Direct Transfer Application Part (DTAP) message is transmitted by the Base Station Controller BSC encapsulated in a BSSMAP (BSS Management Application Part) message. In this information, the identification of the momen-tan serving cell (cell ID) and the identification of the corresponding cell area (LAC) is included. The associated information element is called CL3I (Complete Layer 3 Information, complete layer) and it is part of the BSSMAP message. If necessary, the BSSMAP message is sent as an optional parameter in a connection request (CR) when an SS7 connection is established between the base station controller BSC and the (associated) central mobile switching center MSC. For its part, the central mobile switching center MSC will accept the location update request (Location Updating Accept) or reject it (Location Updating Reject), cf. The signaling processes according to FIG. 5 are also shown overall in FIGS. 4 and 5. The following standardized signaling messages and processes are shown in a localization update: SCCP signaling connection control part signaling connection control part CR connection request connection request 25 LAC old - old Location Area Code - LAC new - new Location Area Code - Cell ID new - New Cell Identification - CC - Connection Confirm - Connection Confirmation - DT1 - Dataform 1 - Data Form 1 30 - RLSD - Released - Released - RLC Release complete - release complete

From the above brief overview of signaling and protocol stacks in location updating requests, it can be seen that the information of interest here or 35 data for each mobile terminal MS, which changes from one cell area LA A to a subsequent LA B, to the A- Interfaces are available and therefore extracted there and filtered out or separated from other data that is discarded and sent for processing. It is typical that, although within a respective cell area LA, only limited information about the individual cells is available, but that this cell information is sufficient for the position data determination, since in each case the first cell, e.g. Z B1, a cell area, e.g. LA B, is announced when the vehicle with the mobile terminal MS from the one, first cell area LA A in the subsequent, second cell area LA B changes. Via the normal localization update process mentioned above, when changing from a cell area, e.g. LA A, in the following 45 cell range, e.g. LA B, the identification of the new cell area, e.g. LA B, as well as the new first cell Z B1 of this new cell area LA B known. The position of the mobile terminal MS is at the resolution of a cell, namely the first cell, e.g. Z B1, known and not merely in general with the resolution of the associated cell area LA B, so that a good position determination is possible. This is also advantageous if there are several traffic routes at the same time, which are to be monitored separately, or only one of which is to be monitored, since then the respective first cell can be identified, cf. e.g. also the cell Z A2 for the traffic route V 'in FIG. 1.

For the sake of completeness, the formats of the signaling 55 layers above the MTP layers for the case of a DTAP location updating request 10 AT 502 073 B1 will be explained with reference to FIG. The SCCP part provides connectionless and connection-oriented network services above MTP layer 3. While MTP3 provides connection point codes for directing messages to specific signaling sites, the SCCP part provides subsystem numbers to address messages to specific applications 5 or subsystems at those signaling points. Specifically, the SCCP part includes a Routing Label 13, followed by a Message Type Specifying Code 14 that is binding on all messages. This message type code uniquely defines the function and format of each SCCP message. This is followed by a binding fixed part 15, i. a fixed-length binding part for a respective post-cursor type, whereas the subsequent self-binding part 16 is a part of variable length, the name of each parameter in that part and the order in which pointers are sent are implicitly contained in the message type. Finally, there follows an optional part 17, which contains parameters that may or may not occur in the respective message type. Fixed length parameters as well as variable length ones may be included. Each optional parameter contains the parameter name, a length specification and the parameter content.

In this part 17, the BSSAP part is transmitted, which again contains the actual data preceding header data 18 concerning the message type and a data part 19 relating to the length of the message. In the payload, the BSSMAP part is transmitted by following a byte, part 20, the cell identifier 21 and then the layer 3 information 22. The cell identifier 21 includes in a part 23 the element ID, in a part 24 a length indication and in a part 25 a discriminator; This is followed by the cell identification information, namely first the part 26 25 with the location area code (LAC) and then the actual cell identification 27. In the layer 3 information again are first indications 28, 29 relating to element identification (FIG. Element ID) and length, and then in part 30, the contents of the layer 3 information. The base station controller submits the incoming Location Updating request in layer 3 information and sends this message to the associated central mobile switching center MSC.

Within the layer 3 information 30, a protocol discriminator 31 (eg Mobility Management - MM) is then an indication 32 regarding message type, a cipher key sequence number 33, an indication 34 concerning the type of location updating (eg normal or 35 periodic), then the Location Area (cell area) Identification 35, with the MCC code (Mobile Country Code) and the actual LAC code, also the aforementioned terminal class name 36 and finally the identifier of the mobile terminal, part 37 included where this identifier 37 of the terminal may include either the usual IMSI or TMSI identification. 40

As can thus be seen, at this point, thus at the A interface, all the necessary information is present to allow a mobile terminal MS to change from a cell area, e.g. LA A, to the next, e.g. LA B, and to track over several such cell-area changes. Thus, the simple possibility described ben ge-45 ben, in the case of entrainment of mobile terminals MS in vehicles that move on a monitored traffic route V, these mobile terminals MS with the accuracy of a cell (namely always the first cell, eg Z A1 or Z B1, a newly entered cell area) and thus to track from cell area to cell area. In FIG. 7, the data acquisition at a central mobile switching center MSC is shown in more detail with the aid of a probe 4 in the form of a network card, wherein the network card inductively senses the standard E1 connections present there and thus the data transmitted on these E1 connections to the data processing unit 7, also called probe server transmits. With the bus system 38 it is indicated that corresponding data transmissions to the unit 7 take place from a plurality of such probes 55 4. The designation "ΕΓ is a 1 1 AT 502 073 B1 CEPT standard with a transmission rate of 2,048 Mbit / s, whereby 30 64 kbit channels (digital channels) for voice and data transmissions as well as a 64 kbit / s signaling channel as well as further A 64 kbit / s channel is available for framing and maintenance. The replaceable probes 4 in the form of network cards E1 / T1 are per se standard network cards, as provided by various manufacturers, such as to perform internal monitoring by the network operator, and these network cards can be used for the data acquisition invention in the same way become.

In detail, the network card probes 4 can be installed directly in the probe server 7, which is thus arranged in the region of the E1 connections. The probe server 7 is a computer which subjects the captured data to first processing. The data processing unit 7 may further be associated with a database system 8 having a plurality of database servers 39 in which the recorded data is kept available for computer access.

In particular, in the configuration according to FIG. 7, the distributed database can be the database 8 according to FIG. 3, and the probe server 7 contains the monitoring unit 5 and the data filter unit 6 according to FIG. 3. The data filter unit 6 is also called "Parser". The mode of operation of this combined data processing unit 7 will be explained in more detail below with reference to the diagram according to FIG. 8 and the flowchart according to FIG. 8A.

8 illustrates in detail for the "parser" 6 that in a module 40 a message is taken over from an affected connection, according to which in a module 41 messages from irrelevant cells are discarded. According to a module 42, the locati on updating requests are then detected by filtering, and in a module 43 the complete layer 3 information including the cell identification (cell ID) and the location area identification (LAC) is read , The location updating request including the MS identifier (the TMSI / IMSI) and the location area code LAC is then read in the module 44, and then the data thus obtained is provided with a time stamp in the module 45. The time stamp data is taken from a system-internal clock. Following this, the data or messages with associated time stamp are finally stored in the database unit 8 or 39, s. Block 46.

According to the associated flowchart shown in Fig. 8A, after the arrival of each message, s. Field 50, in a query field 51, checks whether or not the message belongs to a cell to be monitored (e.g., Z B1 of Figure 1), and if not, moves on to field 52 to wait for the next message. If, on the other hand, a cell of interest is involved, then in block 53 the received message is read and in block 54 the protocols are analyzed as described. Thereafter, an inquiry field 55 queries whether a Location Updating (LU) request (LU Req) is present; if so, the LU query is queued in block 56. If there is no LU request, i. if the result of the query in field 55 is negative, a next inquiry field 57 checks whether there is a Location Updating Accept message (LU Accept) and, if so, according to box 58 it is checked whether a corresponding request is already in the queue is, s. Block 56. If appropriate, then a corresponding entry of the listed data is made in the database 8, s. Block 59 in Fig. 8A. However, if it is determined in the query according to field 57 that there is no LU assumption, then in accordance with query field 60 it is queried whether there is an LU reject (LU reject); if not, in this process, the system returns to block 52 and waits for the next message; if, on the other hand, the query result in field 60 is positive, it is again checked in accordance with an inquiry field 61 whether the LU request is in the queue, and if so, the LU request is deleted from the queue according to block 62. Incidentally, the system returns to block 52 and waits for the next message. 1 2 AT 502 073 B1

On the basis of the position data thus obtained and stored with MS identification, it is now possible, in particular using conventional statistical methods, to obtain information concerning the traffic flow on the particular traffic route V considered. On the one hand, estimates of the traffic density on the traffic route V can be obtained from the filtered signaling data by smoothing with a conventional data filter algorithm, the speed of the individual subscribers, i. the individual vehicles in which mobile terminals MS are carried are estimated, wherein each of the average speed of a vehicle or more precisely a mobile terminal by a cell range, e.g. LA A, as well as by further cell areas along the Trafficwe-io ges V is determined. From these vehicle speeds, as well as from the estimation of the traffic density, further insights regarding the traffic situation on the observed traffic route can be obtained, such as assumptions regarding congestion, crawling traffic, unrestricted traffic and the like traffic situations. With regard to the density of the traffic volume on the respective monitored traffic route V, the mobile terminals MS in each case simply move in a vehicle moving along the travel path V, in each case entering a new cell area under identification of the first cell of these cells Range, and these events are summed over time; It is expedient, for trend detections, etc., also made a smoothing 20 of the filtered data according to a conventional method, as shown in Fig. 9 is illustrated. In this Fig. 9, the upper curve 70 shows the smoothed data corresponding to the smoothed data of the actual traffic detected by means of sensors installed on the traffic route V on the traffic route V over time (in hours); the actual traffic flow is indicated by dotted lines 71, whereby it can be seen that very large momentary fluctuations are present here, so that an averaging or smoothing is recommended. Furthermore, the average curve 72 in FIG. 9 shows the traffic detected due to mobile terminals MS carried along in vehicles, namely on the basis of the aforementioned location updates, whereas the actual "high-frequency" traffic stream detected on the basis of the location updates with the aid of dotted lines 73 is illustrated. From FIG. 9, 30 can be seen that after the averaging carried out, the data curve 72, which was obtained on the basis of the location updates, corresponds relatively well in qualitative terms to the actual traffic volume curve 70, so that based on empirical values based on the data -Curve 72 can be closed to the actual traffic. The lower values of the curve 72 in comparison to the curve 70 result from the fact that not every vehicle carries a switched on mobile terminal, and on the other hand it is also conceivable that if such terminals are carried along, they should be assigned to other network operators are. In the present example, it follows that approximately 1/3 of the vehicles carries an activated mobile terminal of the affected network operator with it. From this it is possible to draw inferences (about 40 by multiplying by a corresponding factor) to the total volume of traffic as well as to the developments, for example at peak times in the traffic situation, with good approximation and reliability.

For data smoothing, that is, for averaging, various methods known per se can be used, such as the Moving Average 45 Filter, the Exponentially Weighted Moving Average Filter, and also an Exponentially Weighted Moving Average Filter simple low-pass filtering or the Kalman filtering method. These methods are well known and need no further explanation. In any case, with the filtered, averaged data trend estimates can be derived in a reliable manner, although, as studies have shown so smoothing with a Kalman filter for predictions in the traffic is less suitable.

Like FIG. 9, FIG. 10 also relates to a concrete test case, wherein data relating to the actual traffic volume have been recorded in detail for a day with the aid of sensors installed on a motorway, cf. the curve 80 in Fig. 10. Parallel to 1 3 AT 502 073 B1 was - see. the curve 81 - detects the traffic based on the location updates regarding mobile devices, in which case further in terms of tracking the vehicles (ie when the vehicles with the mobile terminal MS several cell areas traverse one behind the other and thus traced by several cell areas in a row the dash-dotted curve 82 is obtained. Again, due to the principle of the individual curves 80, 81 and 82, that a good correlation of the curves is given, so that it is permissible, based on the data about as the curve 81 or the curve 82 on the entire traffic flow according to curve 80 conclusions. It should also be mentioned here that in FIG. 10 a failure of a sensor was detected in the actual traffic data curve 80 after approximately 10 hours, so that a break-in 83 occurred in the curve 80 there. In addition, in the present monitoring system, after about 13 hours of the observation period, the monitoring system failed for about one hour, which is indicated by a break 84 in curves 81 and 82. In any case, apart from these failures 83, 84 in the data acquisition, it turns out that the curves 81 and 82 are quite representative, so that the underlying data is suitable for obtaining the desired traffic flow information.

In the data analysis in the analysis unit 9 (FIG. 3), the individual cell identifications are assigned in a conventional manner 20 the (known) geographic coordinates which are taken from the database 10. This assignment can be made using conventional algorithms or map data mappings.

In the evaluation of the data, only those mobile terminals MS, i. Participants or vehicles, which are used in predefined cells, e.g. Z B1 in Fig. 1, which have exceeded cell range limits. This essentially involves counting the participants at the points concerned. Then, subscribers can be tracked over at least two range changes, and due to the time stamps at the respective first cells, e.g. Z A1 and Z B1, mean time for traversing the respective cell area, e.g. LA A, determined. This determination of the average speed can also be carried out over several cell area boundaries, which corresponds to a further "tracking" of the affected participants. It is now possible to discard those subscribers or terminals MS whose speed does not fall within a predetermined interval, whereby, of course, the prevailing traffic conditions (free traffic, traffic jam, traffic jam, etc.) must be taken into account. Furthermore, all public transport users can also be excluded by comparing the periodic peaks corresponding to the travel times of the vehicles in the recorded data curves obtained on the basis of public transport; another possibility is to ignore public transport by comparing the data obtained with 40 historical data and public transport timetables.

Furthermore, multiple location updates resulting from the so-called ping-pong effect can be filtered out. In this way, it is altogether possible with the described technique to analyze traffic conditions, such as estimating the traffic volume, or to determine the average speed of the vehicles, as well as the number of calls from the considered traffic volume or the number of times subscribers be called in the considered traffic route area, can be determined. 50

As mentioned, the principle described above applies in the same way as for the GSM network also for other cellular radio network systems, and the invention is thus not limited to the application to the GSM network described here by way of example. 55

Claims (22)

AT 502 073 B1 Claims: 1. A method for obtaining traffic flow information, wherein the position data including an identifier of at least one mobile terminal (MS) carried in a vehicle consists of signaling data between base stations (BTS) and at least one central cell (MSC) of a cellular network with cell cells combined in cells, these position data combined with time stamp data, and this combined position data map data are assigned, with which they are processed to obtain the traffic flow io information, characterized characterized in that the position data obtained from signaling data at an entry of the respective vehicle in a new cell area (IA A, LA B) on the basis of the identification of the first cell (Z B1) in the new cell area and for this purpose the signaling data in the area at least one central mobile services switching center (MSC) at the interface (A) between this 15 central mobile services switching center (MSC) and associated, the individual cell areas (LA) defining base station controllers (BSC) are taken. 2. The method according to claim 1, characterized in that in the extraction of the position data from the signaling data of the position / identification of the respective first cell 20 (Z A1, Z B1) of the new cell area (LA A, LA B) referring Part is separated. 3. The method according to claim 2, characterized in that for the removal of the signaling data in the region of the central mobile switching center (MSC), the identification of the first 25 first cell (Z B1) is specified and discarded signaling data from other cells (Z) due to their other identifications become. 4. The method according to claim 3, characterized in that extracted by means of data filtering from the signaling data localization update data and only these localization update data are stored. 5. The method according to any one of claims 1 to 4, characterized in that from the difference of the time stamp data of when entering first cells (Z A1, Z B1) successive cell areas (LA A, LA B) obtained position data below Assignment of the 35 map data, the average speed of movement of the vehicle by the first (LA A) of the two successive cell areas (LA A, LA B) is calculated. 6. The method according to any one of claims 1 to 5, characterized in that in the data processing those position data that indicate in mass transit means, in particular 40 public transport, entrained mobile devices (MS) discarded who the. 7. The method according to any one of claims 1 to 6, characterized in that in the data processing those position data that have been provided for a cell area (LA) only with a time stamp 45, as in the considered cell area interrupt their journey de vehicles are subjected to only based on the counting of vehicles data processing. 8. The method according to any one of claims 1 to 7, characterized in that in the data processing, the data used to obtain the traffic flow information is smoothed by data filters. 9. The method according to any one of claims 1 to 8, characterized in that on the basis of the combined position and map data an estimate of the traffic density and / or 55 a mean traffic speed at predetermined times on predetermined driving 1 5 AT 502 073 B1 stretch (V ) is made. 10. A system for obtaining traffic flow information, in which for obtaining position data including an identifier of at least one mobile terminal (MS) carried in a vehicle 5, signaling data is transmitted between base stations (BTS) and at least one central mobile switching center (MSC) Cellular network with cells grouped in cell areas, probes (4) are arranged at the connections between the base stations and the central mobile switching center, and a monitoring unit (5) is connected to the probes (4) in order to detect signaling data that is sent to an analysis unit ( 9), which are further associated with database data (10) for map data, characterized in that the probes (4) in the region of the central mobile switching center (MSC) at their interfaces (A) to each one cell area (LA A, LA B) base station controllers (BSC) are arranged to control the P data from signaling data at an entry of the respective vehicle into a new cell area (e.g. LA B) based on the identity of the first cell (e.g., Z B1) in the new cell area (LA B). 11. System according to claim 10, characterized by a data processing unit (7) 20 between the probes (4) and the analysis unit (9), which data processing unit (7) is arranged for assigning time stamp data to the individual position data. 12. System according to claim 11, characterized in that the data processing unit (7) comprises a data filter unit (6). 25 13. System according to claim 12, characterized in that the data filter unit (6) is set up from the signaling data to the position / identifier of the respective first cell (Z A1, Z B1) of the new cell area (LA A, LA B ) separating part of the data. 30 14. System according to any one of claims 11 to 13, characterized in that the data processing unit (7) is adapted to extract the signaling data from predetermined first cells and those of other cells (Z) than the predetermined first cells (Z A1, Z B1) of the cell areas (LA A, LA B) to discard. 35 15. System according to any one of claims 11 to 14, characterized in that the data processing unit (7) is arranged to separate from the signaling data localization update data and to discard all other data. 16. System according to any one of claims 10 to 15, characterized in that the analysis unit (9) is set up, from the difference of the time stamp data of when entering first cells (Z A1, Z B1) successive cell areas ( LA A, LA B) obtained position data, the map maps the average speed of movement of the vehicle by the first (LA A) of the two successive cell 45 areas to calculate. 17. System according to any one of claims 10 to 16, characterized in that the analysis unit (9) is set up to discard those position data which point to mobile devices (MS) carried along in mass transit means, in particular public transport. 18. System according to any one of claims 10 to 17, characterized in that the analysis unit (9) is arranged, those position data, which were provided only with a time stamp, as pointing in the considered cell area (LA) their drive interrupting vehicles 55 subject to data processing based solely on counting vehicles to 16 AT 502 073 B1. 19. System according to any one of claims 10 to 18, characterized in that the analysis unit (9) is set up to smooth the data used for obtaining the traffic flow information by means of data filters. 20. System according to any one of claims 10 to 19, characterized in that the analysis unit (9) is adapted to make on the basis of the combined position and map data an estimate of the traffic volume at predetermined times on predetermined lanes. 21. System according to any one of claims 10 to 20, characterized in that the probes (4) are formed by equipped with inductive probes network cards. 22. System according to any one of claims 10 to 21, characterized in that the probes (4) and downstream units (7, 9) are installed independently of the cellular network. For this purpose 8 sheets of drawings 20 25 30 35 40 45 50 55