Positioning systems and methods

• US 20020160788A1
• Filed: 03/15/2001
• Published: 10/31/2002
• Est. Priority Date: 02/23/2001
• Status: Active Grant

• Current Assignee: Cambridge Positioning Systems Limited (Qualcomm, Inc.)
• Original Assignee: Cambridge Positioning Systems Limited (Qualcomm, Inc.)
• Inventors: Duffett-Smith, Peter James, Brice, James Paul
• Granted Patent: US 6,937,866 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: G01S 2205/002 for traffic control, mobile tracking, guidance, surveillance or anti-collision
• CPC Class Codes: G01S 2205/007 for management of a communication system
• CPC Class Codes: G01S 2205/008 using a mobile telephone network
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/0081 Transmission between base stations
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

There is described a method of providing a positioning service for plural terminals operating in a communication network which may, for example be a GSM telephone network. The terminals have receivers for receiving signals from transmission sources. In the method measurements of the signals received from one or more of the transmission sources by the receivers are made and the measurements transferred to one or more data nodes. At the data node(s) one or more records of one or more of the measurements are created and at least some of the records are transferred to one or more computing nodes. At the computing node(s) a table of the records transferred to the computing node is maintained and a computation is carried out, using at least part of the table, from which the positions or states of motion or relative positions or relative states of motion of said plural terminals and the transmission time offsets of the transmission sources are extractable.

Claims

1. A method of providing a positioning service for plural terminals operating in a communication network, the terminals having receivers for receiving signals from transmission sources, and the method comprising the steps of

a) making measurements of the signals received from one or more of the transmission sources by the receivers in a plurality of the terminals;

b) transferring said measurements to at least one data node;

c) creating at said at least one data node one or more records of one or more of said measurements;

d) transferring at least some of the records to a computing node;

e) maintaining a table of the records transferred to the computing node; and

f) carrying out a computation, using at least part of the table, from which computation the positions or states of motion or relative positions or relative states of motion of said plural terminals and the transmission time offsets of the transmission sources are extractable.

3. A method according to claim 1 or claim 2, wherein measurements are sent automatically.

4. A method according to claim 1 or claim 2, wherein the measurements are sent in response to broadcast information.

5. A method according to claim 1 or claim 2, wherein the measurements are sent in response to specific requests sent from the network to said mobile terminals.

6. A method according to claim 1 or claim 2, wherein the measurements of the signals received from the transmission sources by the receivers are distributed between plural data nodes.

7. A method according to claim 1 or claim 2, wherein the record held by any data node is a record of a single measurement.

8. A method according to claim 1 or claim 2, wherein the record held by any data node is a list of plural measurements.

9. A method according to claim 1 or claim 2, wherein the components of a record are distributed between two or more sub-nodes.

10. A method according to claim 1 or claim 2, wherein the calculation of position uses the measurements from a number of data nodes.

11. A method according to claim 1 or claim 2, wherein the measurements additionally include estimates of signal strength, signal quality, or other parameters relating to the reception of the signals by the or each receiver from the transmission sources.

12. A method according to claim 1 or claim 2, wherein calculation of location includes information relating to other aspects of a receiver'"'"'s state, for example its position measured by other means, or its velocity, or its height above sea level.

13. A method according to claim 1 or claim 2, wherein calculation of location includes using measurements from GPS systems.

14. A method according to claim 1 or claim 2, wherein a request is transmitted to the terminals to send their measurements to update the records in the data nodes before the position calculation is made.

15. A method according to claim 14, wherein the request is broadcast by a specific cell.

16. A method according to claim 14, wherein the request is broadcast by a group of cells.

17. A method according to claim 14, wherein the request is broadcast to specific terminals known to the system to be operating in the right area when last they reported in.

18. A method according to claim 14, wherein the request is broadcast to specific terminals in active connection with the network.

19. A method according to claim 14, wherein the request for measurements is broadcast from terminals that have measurements on specific BTSs.

20. A method according to claim 14, wherein the request for measurements is broadcast from terminals that have predetermined identifiers.

23. A method according to claim 1 or claim 2, wherein a computing node is within or connected to a mobile terminal.

24. A method according to claim 1 or claim 2, used to calculate, simultaneously, the positions or states of motion or relative positions or relative states of motion of plural terminals whose measurements form part of the record.

25. A communication network adapted to locate terminals connected to the network in accordance with the method of claim 1 or claim 2.

37. A communication terminal adapted to send measurements in accordance with the method defined in claim 1 or claim 2, and a data node adapted to receive such measurements whereby said measurements may form part of the calculation of the position or relative position or state of motion or relative state of motion of another communication terminal.

40. A method according to claim 1 or claim 2, which includes maintaining a list of the values of the transmission time offsets of BTSs in the network.

41. A method according to claim 40, further comprising monitoring the degree of synchronisation of the network using said list of the values of the transmission time offsets.

2. A method of determining the position or state of motion or relative position or relative state of motion of a mobile terminal in a communication network, the mobile terminal having a receiver for receiving signals from transmission sources, the method comprising the steps of

a. acquiring at a data node, measurements of the signals received from one or more of the transmission sources by the receiver in the first mobile terminal whose position or state of motion or relative position or relative state of motion is to be determined;

b. calculating a coarse position or relative position of the first mobile terminal;

c. receiving at said data node measurements made by the receiver in a second mobile terminal near to the coarse position or relative position of the first terminal, together with information about the position of the mobile unit if available; and

d. calculating at any one or more computing nodes the position or state of motion or relative position or relative state of motion of either or both of the said mobile terminals using at least some of the measurements made by the first and second mobile terminals.

21. A method according to claim 2, wherein the second mobile terminal is dispatched to the coarse position or relative position of the first terminal if one is not already near the coarse position or relative position of the first terminal.

22. A method according to claim 2 or claim 21, wherein the step of calculating a coarse position is made by two or more computing nodes.

27. A communication network according to claim 26, wherein a data node and a computing node are co-located with each other.

28. A communication network according to claim 26, wherein plural data nodes and computing nodes are distributed throughout the network.

29. A communication network according to claim 26, wherein a data node and/or a computing node are part of, or connected to, a terminal operating in the communication network.

30. A communication network according to claim 26, wherein the computing nodes are connected to the communication network.

31. A communication network according to claim 26, wherein the computing nodes comprise part of the communication network.

32. A communication network according to claim 26, wherein the transmission sources include fixed transmitters of the communications network.

33. A communication network according to claim 26, wherein the transmission sources include fixed transmitters of another communication network.

34. A communication network according to claim 26, wherein the transmission sources include transmitters set up for non-telecommunications purposes.

35. A communication network according to claim 26, wherein the transmission sources include transmitters within the fixed and mobile terminals operating in the communications network.

36. A communication network according to claim 26, wherein the transmission sources include satellite transmitters.

26. A communication network having

terminals whose positions or states of motion or relative positions or relative states of motion are to be determined, the terminals each having a receiver for receiving signals from transmission sources and means for making measurements of the signals received from one or more of the transmission sources;

at least one data node having means for acquiring said measurements from said terminals and means for creating one or more records of one or more of said measurements; and

a computing node having means for receiving at least some of the records, means for maintaining a table of the records transferred to the computing node, and means for carrying out a computation, using at least part of the table, from which computation the positions or states of motion or relative positions or relative states of motion of said plural terminals and the transmission time offsets of the transmission sources are extractable.

38. A method of maintaining, within a radio telephone communication network, a record which gives the calculated position of every terminal at its last communication with the network.

39. A method of maintaining, within a radio telephone communication network, a record which gives the serving cell used by every terminal in its last communication with the network.