Handover-based method for anonymous observation of a moving subscriber

• US 20060009222A1
• Filed: 09/19/2005
• Published: 01/12/2006
• Est. Priority Date: 03/24/2003
• Status: Active Grant

• Current Assignee: Elisa Oyj
• Original Assignee: Elisa Matkapuhelinpalvelut Oy (Elisa Oyj)
• Inventors: Nykopp, Juha, Knuuttila, Olli, Kiviranta, Veli-Matti
• Granted Patent: US 7,979,080 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic

Abstract

A location of a subscriber can be observed by means of a mobile network in a completely anonymous way, without a subscriber identifier or a temporary subscriber identifier. At first, a method extracts from a first time slot of a radio channel a message which includes information about a second time slot of a radio channel. The first time slot of a radio channel discloses the current cell of the subscriber and the second time slot of a radio channel discloses a new cell of the subscriber. A location of the subscriber is determined on the basis of the current and the new cell. This location is approximately situated in a geographical intersection area of the current and the new cell. Different kinds of statistics can be deduced from the observations concerning activities of subscribers.

Claims

1. A method for locating anonymously subscribers, said subscribers moving between cells of a mobile network, characterized by the steps of

extracting by extracting means a first message transmitted in the mobile network, the first message defining a current cell of a subscriber of the mobile network and the first message including a piece of information on the basis of which a second message transmitted in the mobile network is to be extracted,

extracting by the extracting means the second message which defines a new cell of the subscriber, wherein the first message and the second message are sent from a base station and/or a base station controller of the mobile network due to at least one handover performed for the subscriber, and

determining by a calculating server a location of said subscriber on the basis of the current cell defined by the first message and the new cell defined by the second message, wherein the location is at least partly situated in a geographical intersection of the cells defined by the first and the second message.

2. The method as in claim 1, characterized in that the first message is a HandOver Command message and the second message is one of the following messages:

a Channel Activation, a Channel Activation Acknowledgement, or a HandOver Detect message.

3. The method as in claim 1, characterized in that the piece of information is a time slot of a radio channel.

4. The method as in claim 2, characterized in that the piece of information is a reference number of a handover when the second message is a Channel Activation message.

5. The method as in claim 2, characterized in that

a first time stamp is attached to the first message which discloses a point of time when the first message was extracted,

a second time stamp is attached to the second message which discloses a point of time when the second message was extracted, and on the basis of a location read from a memory and another location,

a distance which the subscriber has travelled is determined and

a velocity of the subscriber is determined on the basis of the distance of, the first time stamp, and the second time stamp, wherein the distance travelled by the subscriber is the distance between two border areas situated in the geographical intersection of the cells defined by the first and the second message.

6. The method as in claim 1, characterized in that

the second message is a HandOver Command message and the first message is one of the following messages:

a Channel Activation, a Channel Activation Acknowledgement, or a HandOver Detect message.

7. The method a sin claim 6, characterized in that

a time stamp is attached to the location disclosing a point of time when the second message was extracted and

the location of the subscriber, which was first determined, is stored in a memory, and when the current cell of the subscriber is changed to the new cell and the subscriber is moving from the new cell to a subsequent cell,

a third message transmitted in the mobile network is extracted, the third message disclosing the subsequent cell of the subscriber,

another location of the subscriber is determined on the basis of the new cell defined by the second message and the subsequent cell defined by the third message,

the location stored in the memory is read, and on the basis of the read location and the other location,

the distance that the subscriber has travelled across the new cell is determined and

a velocity of the subscriber is determined on the basis of the distance travelled by the subscriber, the time stamp disclosing the point of time when the second message was extracted, and on the basis of another time stamp disclosing the point of time when the third message was extracted.

8. The method as in claim 1, characterized in that the extracting means comprises at least one signal analyzer which is adapted to send data the calculation server.

9. The method as in claim 1, characterized in that a signal first message and the second message are extracted from signal traffic of at least one E1 connection.

10. A system for locating anonymously subscribers, said subscribers moving between cells of a mobile network, characterized in that the system is adapted to:

extract by extracting means a first message transmitted in the mobile network, the first message defining a current cell of a subscriber of the mobile network and the first message including a piece of information on the basis of which a second message transmitted in the mobile network is to be extracted, the extracting means comprising at least one signal analyzer adapted to send data to a calculation server,

extract by the extracting means the second message which defines a new cell of the subscriber, wherein the first message and the second message are sent from a base station and/or a base station controller of the mobile network due to at least one handover performed for the subscriber, and

determine by the calculating server a location of the subscriber on the basis of the current cell defined by the first message and the new cell defined by the second message, wherein the location is at least partly situated in a geographical intersection of the cells defined by the first and the second message.

11. The system as in claim 10, characterized in that the first message is a HandOver Command message and the second message is one of the following messages:

a Channel Activation, a Channel Activation Acknowledgement, or a HandOver Detect message.

12. The system as in claim 10, characterized in that the piece of information is a time slot of a radio channel.

14. The system as in claim 11, characterized in that the system is adapted to:

attach to the first message a first time stamp which discloses a point of time when the first message was extracted,

attach to the second message a second time stamp which discloses a point of time when the second message was extracted, and on the basis of a location read from a memory and another location,

determine a distance which the subscriber has travelled, and

determine a velocity of the subscriber on the basis of the distance, the first time stamp, and the second time stamp, wherein the distance travelled by the subscriber is a distance between two border areas situated in the geographical intersection of the cells defined by the first and the second message.

15. The system as in claim 10, characterized in that the second message is a HandOver Command message and the first message is one the following messages:

a Channel Activation, a Channel Activation Acknowledgement, or a HandOver Detect message.

16. The system as in claim 15, characterized in that the system is adapted to:

attach to the location of the subscriber a time stamp disclosing a point of time when the second message was extracted,

store the location, which was first determined, in a memory, and in order to prepare for a situation when the subscriber moves from the new cell to a subsequent cell

extract a third message which discloses the subsequent cell of the subscriber,

determine another location of the subscriber on the basis of the new cell defined by the second message and the subsequent cell defined by the third message,

read the location stored in the memory,

determine a distance which the subscriber has travelled across the new cell, the determination of the distance being based on the read location and said other location, and

determine a velocity of the subscriber on the basis of the distance travelled by the subscriber, the time stamp disclosing the point of time when the second message was extracted, and another time stamp disclosing the point of time when the third message was extracted.

17. The system as in claim 10, characterized in that the first message and the second message are extracted from signal traffic of at least one E1 connection.

18. The system as in claim 10, characterized in that the first message and the second message are extracted through Abis interface.

13. The system as in 11, characterized in that the piece of information is a reference number of a handover when the second message is a Channel Activation message.