Method for detecting traffic data

• US 7,162,251 B2
• Filed: 06/13/2001
• Issued: 01/09/2007
• Est. Priority Date: 06/14/2000
• Status: Expired due to Fees

• Current Assignee: Vodafone Holding GmbH (Vodafone Group PLC)
• Original Assignee: Vodafone Holding GmbH (Vodafone Group PLC)
• Inventors: Alger, Michael
• Primary Examiner(s): Nguyen; Duc
• Assistant Examiner(s): Cai; Wayne
• Application Number:
  US10/311,567
• Publication Number:
  US 20030153331A1
• Time in Patent Office: 2,036 Days
• Field of Search: 455/414.2, 455/456.1, 455/456.3, 455/456, 455/414.1, 455/422.1, 455/404.2, 455/446, 455/67.11, 701117-119, 340/992, 340988-989, 379/32, 342/457
• US Class Current: 455/456.1
• CPC Class Codes: G08G 1/012 from other sources than vehicle or roadside beacons, e.g. mobile networks
• CPC Class Codes: G08G 1/0133 for classifying traffic situation
• CPC Class Codes: G08G 1/0141 for traffic information dissemination

Abstract

The invention relates to a method for acquiring traffic situation data in a network of traffic routes which is covered by a cellular mobile radio network comprising a multiplicity of base stations and in which a multiplicity of vehicles is moving which are in each case provided with an operating mobile terminal for the mobile radio network. In this method, characteristic patterns of values (called signal transit times in the text which follows), which are representative of the signal transit times with respect to the respective base station during the movement of a terminal along the course of the respective traffic route, are determined and permanently stored at least for some of the individual traffic routes of the network of traffic routes at least for selected base stations, the respective characteristic pattern or a sequence of values representative of this pattern is mapped onto the course of the respective traffic route (calibration). To obtain current traffic situation information, the signal transit times of selected terminals which are located within the transmission area of the respective base station are detected and compared with the stored patterns.

Claims

1. A method for acquiring traffic situation data in a network of traffic routes covered by a cellular mobile radio network having a plurality of base stations communicating with operating mobile terminals in a plurality of vehicles moving in the network of traffic routes, said method comprising:

(a) a calibration phase comprising the steps of;

moving at least one of the mobile terminals along the traffic routes;

determining at a plurality of points on the traffic routes during movement of the at least one of the mobile terminals along the traffic routes signal transit times to respective base stations having a transmission area in which the at least one of the mobile terminals is currently located, each signal transit time being representative of an elapsed time required for transmission of a wireless signal between the at least one of the mobile terminals and one of the respective base stations in the mobile network, whereby the respective base stations exhibit reference patterns of signal transit times at the plurality of points along the traffic routes;

storing for the respective base stations the reference patterns of signal transit times for the traffic routes; and

mapping the reference patterns of signal transit times for the traffic routes onto the traffic routes;

thereby creating a database including a reference map between the reference patterns of signal transit times and the traffic routes; and

(b) a utilization phase comprising the steps of;

detecting signal transit times of selected ones of the mobile terminals to respective base stations

comparing the detected signal transit times with the stored reference patterns of signal transit times;

determining on which traffic route the selected ones of the mobile terminals are currently located using the results of said step of comparing and the reference map;

thereby obtaining information for assessing the traffic situation.

2. The method of claims 1, wherein said step of determining reference patterns comprises statistically evaluating signal transit times for a plurality of mobile terminals moving along the traffic routes.

3. The method of claim 1, wherein said step of determining reference patterns includes continuously acquiring signal transit times for a single mobile terminal moving in a vehicle in the transmission area of at least one of the base stations.

4. The method of claim 1, wherein said step of determining reference patterns comprises determining sets of signal transit times with respect to a plurality of adjacent base stations, wherein a respective location of the mobile terminal corresponds to a specific set of signal transit times.

5. The method of claim 4, wherein said step of detecting signal transit times for selected ones of the mobile terminals also includes identifying a time of the detection of the signal transit time and storing the time of detection with the detected signal transit time.

6. The method of claim 5, further comprising the step of deriving a speed of movement of a mobile terminal along a traffic route using the detected signal transit times and the corresponding times of detection.

7. The method of claim 1, wherein said step of detecting signal transit times for selected ones of the mobile terminals also includes identifying a time of the detection of the signal transit time and said step of storing includes storing the time of detection with the detected signal transit time.

8. The method of claim 7, further comprising the step of deriving a speed of movement of a mobile terminal along a traffic route using the detected signal transit times and the corresponding times of detection.

9. The method of claim 1, further comprising the step of reporting the current traffic situation information to a traffic situation center which covers at least a sector of the mobile cellular network.

10. The method of claim 9, wherein said step of reporting comprises reporting the current traffic situation information to the traffic situation center only when an anomaly is found in the traffic situation of the at least a sector.

11. The method of claim 1, wherein said step of obtaining current traffic situation information comprises selecting the selected ones of the mobile terminals for which signal transit times are to be detected in response to a total number of the mobile terminal currently located in area of detection, wherein the selected ones comprise a percentage of the total number of mobile terminals which decreases as the total number of mobile terminals correspondingly increases.

12. The method of claim 1, further comprising determining a total number of mobile terminals in an area of one of the traffic routes of the network of traffic routes for facilitating assessment of the traffic situation.

13. The method of claim 1, wherein said step of detecting signal transit times for selected ones of the mobile terminals also includes identifying a time of the detection of the signal transit time, said method further comprising considering only one of a plurality of mobile terminals that exhibit the same pattern at the same time.

14. The method of claim 1, wherein the mobile cellular network is a GSM mobile radio network.

15. The method of claim 1, further comprising the step of reducing the smallest measuring unit in the determination of the signal transit time to improve spatial resolution.

16. A system for acquiring traffic situation data in a network of traffic routes covered by a cellular mobile radio network having a plurality of base stations, a plurality of vehicles moving in the network of traffic routes, and each of the plurality of vehicles having an operating mobile terminal for communicating with the mobile radio network, said system comprising:

means for creating a database including

means for determining at a plurality of points on the traffic routes during movement of at least one of the mobile terminals along the traffic routes signal transit times to respective base stations having a transmission area in which the at least one of the mobile terminals is currently located, each signal transit time being representative of an elapsed time required for transmission of a wireless signal between the at least one of the mobile terminals and one of the respective base stations in the mobile network, whereby the respective base stations exhibit reference patterns of signal transit times at the plurality of points along the traffic routes;

means for storing for the respective base stations the reference patterns of signal transit times for the traffic routes; and

means for mapping the reference patterns of signal transit times for the traffic routes onto the traffic routes, and for thereby creating the database including a reference map between the reference patterns of signal transit times and the traffic routes; and

means for using the database to assess a traffic situation including

means for detecting signal transit times of selected ones of the mobile terminals to respective base stations;

means for comparing the detected signal transit times with the stored reference patterns of signal transit times; and

means for determining on which traffic route the selected ones of the mobile terminals are currently located using the results of said means for comparing and the reference map, and thereby for obtaining information for assessing the traffic situation.

17. The system of claim 16, wherein said means for determining reference patterns comprises means for statistically evaluating signal transit times for a plurality of mobile terminals moving along the traffic routes.

18. The system of claim 16, wherein said means for determining reference patterns includes means for continuously acquiring signal transit times for a single mobile terminal moving in a vehicle in the transmission area of at least one of the base stations.

19. The system of claim 16, wherein said means for determining reference patterns comprises determining sets of signal transit times with respect to a plurality of adjacent base stations, wherein a respective location of the mobile terminal corresponds to a specific set of signal transit times.

20. The system of claim 19, wherein said means for detecting signal transit times for selected ones of the mobile terminals also includes means for identifying a time of the detection of the signal transit time and said means for storing includes means for storing the time of detection with the signal transit time.

21. The system of claim 20, further comprising means for deriving a speed of movement of a mobile terminal along a traffic route using the detected signal transit times and the corresponding times of detection.

22. The system of claim 16, wherein said means for detecting signal transit times for selected ones of the mobile terminals also includes means for identifying a time of the detection of the signal transit time and said means for storing includes means for storing the time of detection with the signal transit time.

23. The system of claim 22, further comprising means for deriving a speed of movement of a mobile terminal along a traffic route using the detected signal transit times and the corresponding times of detection.

24. The system of claim 16, further comprising means for reporting the current traffic situation information to a traffic situation center which covers at least a sector of the mobile cellular network.

25. The system of claim 24, wherein said means for reporting comprises means for reporting the current traffic situation information to the traffic situation center only when an anomaly is found in the traffic situation of the at least a sector.

26. The system of claim 16, wherein said means for obtaining current traffic situation information comprises selecting the selected ones of the mobile terminals for which signal transit times are to be detected in response to a total number of the mobile terminal currently located in area of detection, wherein the selected ones comprise a percentage of the total number of mobile terminals which decreases as the total number of mobile terminals correspondingly increases.

27. The system of claim 16, further comprising means for determining a total number of mobile terminals in an area of one of the traffic routes of the network of traffic routes for facilitating assessment of the traffic situation.

28. The system of claim 16, wherein said means for detecting signal transit times for selected ones of the mobile terminals also includes identifying a time of the detection of the signal transit time, said system further comprising means for considering only one of a plurality of mobile terminals that exhibit the same pattern at the same time.

29. The system of claim 16, wherein the mobile cellular network is a GSM mobile radio network.

30. The system of claim 16, further comprising the step of reducing the smallest measuring unit in the determination of the signal transit time to improve spatial resolution.