GENERATING ENTRIES FOR A DATABASE SUPPORTING A POSITIONING OF A MOBILE TERMINAL

• US 20040104841A1
• Filed: 12/03/2002
• Published: 06/03/2004
• Est. Priority Date: 12/03/2002
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Syrjarinne, Paula
• Granted Patent: US 6,774,842 B2
• Time in Patent Office: Days
• US Class Current: 342/357.13
• CPC Class Codes: G01S 19/06 employing an initial estimate of the location of the receiver as aiding data or in generating aiding data
• CPC Class Codes: G01S 2205/008 using a mobile telephone network
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 64/003 locating network equipment

Abstract

The invention relates to a method for generating entries for a database, which database is destined for supporting a positioning of a mobile terminal. In order to enable the generation of information for this database, the method calculating at least one position of a mobile terminal in a cell of a cellular network. The method further comprises determining geographical information on this cell based on the at least one calculated position of the mobile terminal in this cell. Finally, the method comprises providing the determined geographical information together with an identification of the cell for storage in the database. The invention relates equally to a unit and to a system in which such a method is implemented.

Claims

1. A method for generating entries for a database, which database is destined for supporting a positioning of a mobile terminal, said method comprising:

calculating at least one position of a mobile terminal in a cell of a cellular network;

determining geographical information on said cell based on said at least one calculated position of said mobile terminal in said cell; and

providing said determined geographical information together with an identification of said cell for storage in said database.

2. The method according to claim 1, wherein said cellular network provides a notification to said mobile terminal when said mobile terminal enters a new cell of said cellular network together with said identification of said cell.

3. The method according to claim 1, wherein a position of said mobile terminal is calculated when said mobile terminal enters said cell, and wherein said geographical information on said cell is determined to correspond to the coordinates of said calculated position.

4. The method according to claim 1, wherein a first position of said mobile terminal is calculated when said mobile terminal enters said cell, wherein a second position of said mobile terminal is calculated when said mobile terminal exits said cell, and wherein said geographical information on said cell is determined to correspond to the mean of the coordinates of said first position and said second position.

5. The method according to claim 1, wherein positions of said mobile terminal within said cell are calculated at different points of time, and wherein said geographical information on said cell is determined based on a statistical evaluation of a plurality of calculated positions of said mobile terminal within said cell.

6. The method according to claim 1, wherein positions of said mobile terminal within said cell are calculated at different points of time, and wherein said geographical information on said cell is determined to correspond to the mean of the coordinates of those two calculated positions which are most distant to each other among a plurality of calculated positions of said mobile terminal within said cell.

7. The method according to claim 1, wherein said cell is currently a serving cell for said mobile terminal, wherein positions of said mobile terminal within said cell are calculated at different points of time, wherein at a plurality of calculated positions of said mobile terminal within said cell a dedicated value of a timing advance parameter is received by said mobile terminal from a base transceiver station of said cellular network serving said cell, and wherein said geographical information on said cell is determined to correspond to the coordinates of a position at which the smallest value of said timing advance parameter is received.

8. The method according to claim 1, further comprising estimating a cell range for said cell and providing said estimated cell range together with said geographical information and said identification of said cell for storage in said database.

9. The method according to claim 8, wherein a first position of said mobile termninal is calculated when said mobile terminal enters said cell, wherein a second position of said mobile terminal is calculated when said mobile terminal exits said cell, and wherein said cell range is estimated to correspond to half of the distance between said first position and said second position.

10. The method according to claim 8, wherein positions of said mobile terminal within said cell are calculated at different points of time, and wherein said cell range is estimated to correspond to half of the distance between those two calculated positions which are most distant to each other among a plurality of calculated positions of said mobile terminal within said cell.

11. The method according to claim 8, wherein said cell is currently a serving cell for said mobile terminal, wherein at a plurality of positions of said mobile terminal within said cell a dedicated value of a timing advance parameter is received by said mobile terminal from a base transceiver station of said cellular network serving said cell, and wherein said cell range is estimated based on the length of a propagation path of signals transmitted from said base transceiver station to said mobile station at a position associated to the largest value of said timing advance parameter, which length of propagation path is indicated by said largest value of said timing advance parameter.

12. The method according to claim 1, wherein said at least one position of a mobile terminal in a cell of a cellular network is calculated based on satellite signals.

13. The method according to claim 1, further comprising storing said provided geographical information together with said provided identification of said cell as well as cell range information, if provided, in said database.

14. The method according to claim 13, further comprising updating said database when new information on a specific cell is provided when said mobile terminal reenters said cell.

15. The method according to claim 14, wherein said database information includes an estimate of the cell coordinates and an estimate of the cell radius, wherein at least one position of said mobile terminal in said cell is calculated when said mobile terminal reenters said cell, and wherein said updating comprises

determining a circular area of which the center is given by said estimated cell coordinates and of which the radius is given by said estimated cell radius;

determining whether at least one of said at least one position calculated after said mobile terminal reentered said cell lies outside of said determined circular area;

connecting a calculated position which is determined to lie outside of said determined circular area with the center of said circular area by a straight line and extending said straight line to the border of said circular area;

determining new cell coordinates to correspond to the mean of the coordinates of the endpoints of said straight line; and

estimating a new cell radius to correspond to one half of the length of said straight line.

16. The method according to claim 15, wherein a plurality of positions of said mobile terminal in said cell is calculated when said mobile terminal reenters said cell, and wherein said updating comprises determining which one of all calculated positions which are determined to lie outside of said determined circular area is most distant to said center of said circular area, and employing said most distant calculated position as starting point for said straight line.

17. The method according to claim 13, wherein said identification of a cell is composed of values of hierarchical components, wherein said database has a hierarchical structure which comprises a dedicated level for each hierarchical component of said identification, each level comprising nodes representing a different value of a specific hierarchical component, wherein nodes of the highest level of said hierarchical structure are connected in a chained line, a first node of said highest level nodes being accessible via a root node, wherein each node of a specific level except for the lowest level points to a chained line of nodes in the respective subordinate level, and wherein each node of the lowest level comprises data with geographical information.

18. The method according to claim 17, wherein provided geographical information on a new cell is inserted into said database such that a respective node representing a value of a hierarchical component identifying said cell which is not yet comprised in said hierarchical structure is inserted at the beginning of the respective line of nodes.

19. The method according to claim 17, wherein in case geographical information for a specific cell is extracted from said database, those nodes representing the values of the hierarchical components of the identification of said cell are shifted to the first place in their respective line.

20. The method according to claim 13, wherein said database comprises a hash table for storing geographical information for a plurality of cells, the slot in said table for storing said geographical information for a specific cell being determined by a hash function applied to an identification of said specific cell.

21. The method according to claim 20, wherein in case a slot of said hash table determined for storing geographical information on a specific cell is already used for storing geographical information on another cell, a pointer associated to said determined slot is used for pointing to a list of additional slots in one of which said geographical information on said specific cell is stored.

22. A unit comprising processing means for determining geographical information on a cell of a cellular network based on at least one calculated position of a mobile terminal in said cell and for providing said determined geographical information together with an identification of said cell for storage in a database which database is destined for supporting a positioning of a mobile terminal.

23. The unit according to claim 22, further comprising receiving means for receiving a notification transmitted from said cellular network to said mobile terminal when said mobile terminal enters a new cell of said cellular network together with an identification of said cell.

24. The unit according to claim 22, wherein said processing means determine said geographical information on said cell to correspond to the coordinates of a calculated position of said mobile terminal within said cell, which calculated position was calculated when said mobile terminal entered said cell.

25. The unit according to claim 22, wherein said processing means determine said geographical information on said cell to correspond to the mean of the coordinates of a first position and a second position of said mobile terminal, which first position was calculated when said mobile terminal entered said cell, and which second position was calculated when said mobile terminal exited said cell.

26. The unit according to claim 22, wherein said processing means determine said geographical information on a cell based on a statistical evaluation of a plurality of calculated positions of said mobile terminal within said cell, which plurality of calculated positions was calculated at different points of time.

27. The unit according to claim 22, wherein said processing means determine said geographical information on said cell to correspond to the mean of the coordinates of those two calculated positions which are most distant to each other among a plurality of calculated positions of said mobile terminal within said cell, which plurality of calculated positions was calculated at different points of time.

28. The unit according to claim 22, wherein said processing means receive a dedicated value of a timing advance parameter originating from a base transceiver station of said cellular network serving said cell, which cell is currently a serving cell for said mobile terminal, for a plurality of calculated positions, which plurality of calculated positions was calculated at different points of time, and wherein said processing means determine said geographical information on said cell to correspond to the coordinates of a position for which the smallest value of said timing advance parameter is received.

29. The unit according to claim 22, wherein said processing means further estimate a cell range for said cell and provide said estimated cell range together with said geographical information and said identification of said cell for storage in said database.

30. The unit according to claim 29, wherein said processing means estimate said cell range to correspond to half of the distance between a first position and a second position of said mobile terminal, which first position was calculated when said mobile terminal entered said cell, and which second position was calculated when said mobile terminal exited said cell.

31. The unit according to claim 29, wherein said processing means estimate said cell range to correspond to half of the distance between those two calculated positions which are most distant to each other among a plurality of calculated positions of said mobile terminal within said cell, which plurality of calculated positions was calculated at different points of time.

32. The unit according to claim 29, wherein said processing means receive a dedicated value of a timing advance parameter originating from a base transceiver station of said cellular network serving said cell, which cell is currently a serving cell for said mobile terminal, for a plurality of positions of said mobile terminal in said cell, and wherein said processing means estimate said cell range based on the length of a propagation path of signals transmitted from said base transceiver station to said mobile station at a position associated to the largest value of said timing advance parameter, which length of propagation path is indicated by said largest value of said timing advance parameter.

33. The unit according to claim 22, further comprising processing means for calculating said at least one position of said mobile terminal.

34. The unit according to claim 22, further comprising processing means for calculating said at least one position of said mobile terminal based on satellite signals.

35. The unit according to claim 22, further comprising a database for storing said provided geographical information together with said provided identification of said cell as well as cell range information, if provided.

36. The unit according to claim 35, wherein said processing means update said database when new information on a specific cell is provided when said mobile terminal reenters said cell.

37. The unit according to claim 36, wherein said processing means provide an estimate of the cell coordinates and an estimate of the cell radius together with an identification of said cell for storage in said database, and wherein said processing means

determine a circular area of which the center is given by said estimated cell coordinates and of which the radius is given by said estimated cell radius;

determine whether at least one position of said mobile terminal in said cell which was calculated after said mobile terminal reentered said cell lies outside of said determined circular area;

connect a calculated position which is determined to lie outside of said determined circular area with the center of said circular area by a straight line and extend said straight line to the border of said circular area;

determine new cell coordinates to correspond to the mean of the coordinates of the endpoints of said straight line; and

estimate a new cell radius to correspond to one half of the length of said straight line.

38. The unit according to claim 36, wherein said processing means determine which one of a plurality of positions which were calculated when said mobile terminal reentered said cell and which are determined to lie outside of said determined circular area is most distant to said center of said circular area, and employ said most distant calculated position as starting point for said straight line.

39. The unit according to claim 35, wherein said identification of a cell is composed of values of hierarchical components, wherein said database has a hierarchical structure which comprises a dedicated level for each hierarchical component of said identification, each level comprising nodes representing a different value of a specific hierarchical component, wherein nodes of the highest level of said hierarchical structure are connected in a chained line, a first node of said highest level nodes being accessible via a root node, wherein each node of a specific level except for the lowest level points to a chained line of nodes in the respective subordinate level, and wherein each node of the lowest level comprises data with geographical information.

40. The unit according to claim 39, wherein said processing means insert provided geographical information on a new cell into said database such that a respective node representing a value of a hierarchical component identifying said cell which is not yet comprised in said hierarchical structure is inserted at the beginning of the respective line of nodes.

41. The unit according to claim 39, wherein in case said processing means extract geographical information for a specific cell from said database, said processing means shift those nodes representing the values of the hierarchical components of the identification of said cell to the first place in their respective line.

42. The unit according to claim 35, wherein said database comprises a hash table for storing geographical information for a plurality of cells, and wherein said processing means determine the slot in said table for storing said geographical information for a specific cell by applying a hash function to an identification of said specific cell.

43. The unit according to claim 42, wherein in case said processing means determine a slot of said hash table for storing geographical information on a specific cell which is already used for storing geographical information on another cell, said processing means store said geographical information on said specific cell in a slot of a list of additional slots to which a pointer associated to said determined slot is pointing.

44. The unit according to claim 22, wherein said unit is a mobile terminal comprising means for accessing a cellular network.

45. The unit according to claim 44, wherein said at least one position of said mobile terminal is calculated based on satellite signals, and wherein said mobile terminal further comprises a receiver of a satellite positioning system for receiving said satellite signals.

46. The unit according to claim 22, wherein said unit is a network unit which is accessible for mobile terminals.

47. A positioning system comprising a mobile terminal with communication means for communicating with a cellular network, a database destined for supporting a positioning of said mobile terminal, processing means for calculating at least one position of said mobile terminal in a cell of said cellular network and processing means for determining geographical information on said cell based on said at least one calculated position of said mobile terminal in said cell and for providing said determined geographical information together with an identification of said cell for storage in said database.

48. The positioning system according to claim 47, wherein said communication means of said mobile terminal comprising receiving means for receiving a notification transmitted from said cellular network to said mobile terminal when said mobile terminal enters a new cell of said cellular network together with an identification of said cell.

49. The positioning system according to claim 47, wherein said processing means for calculating at least one position calculate a position of said mobile terminal when said mobile terminal enters a cell, and wherein said processing means for determining geographical information determine said geographical information to correspond to the co-ordinates of said calculated position.

50. The positioning system according to claim 47, wherein said processing means for calculating at least one position in said cell calculate a first position of said mobile terminal when said mobile terminal enters said cell, wherein said processing means for calculating at least one position calculate a second position of said mobile terminal when said mobile terminal exits said cell, and wherein said processing means for determining geographical information determine said geographical information on said cell to correspond to the mean of the coordinates of said first position and said second position.

51. The positioning system according to claim 47, wherein said processing means for calculating at least one position calculate positions of said mobile terminal within said cell at different points of time, and wherein said processing means for determining geographical information determine said geographical information on a cell based on a statistical evaluation of a plurality of calculated positions of said mobile terminal within said cell.

52. The positioning system according to claim 47, wherein said processing means for calculating at least one position calculate positions of said mobile terminal within said cell at different points of time, and wherein said processing means for determining geographical information determine said geographical information on said cell to correspond to the mean of the coordinates of those two calculated positions which are most distant to each other among a plurality of calculated positions of said mobile terminal within said cell.

53. The positioning system according to claim 47, wherein said processing means for calculating at least one position calculate positions of said mobile terminal within said cell, which cell is currently a serving cell for said mobile terminal, at different points of time, wherein said processing means for determining geographical information receive a dedicated value of a timing advance parameter originating from a base transceiver station of said cellular network serving said cell for a plurality of said calculated positions, and wherein said processing means for determining geographical information determine said geographical information on said cell to correspond to the coordinates of a position for which the smallest value of said timing advance parameter is received.

54. The positioning system according to claim 47, wherein said processing means for determining geographical information fuirther estimate a cell range for said cell and provide said estimated cell range together with said geographical information and said identification of said cell for storage in said database.

55. The positioning system according to claim 54, wherein said processing means for calculating at least one position calculate a first position of said mobile terminal when said mobile terminal enters said cell, wherein said processing means for calculating at least one position calculate a second position of said mobile terminal when said mobile terminal exits said cell, and wherein said processing means for determining geographical information estimate said cell range to correspond to half of the distance between said first position and said second position.

56. The positioning system according to claim 54, wherein said processing means for calculating at least one position calculate positions of said mobile terminal within said cell at different points of time, and wherein said processing means for determining geographical information estimate said cell range to correspond to half of the distance between those two calculated positions which are most distant to each other among a plurality of calculated positions of said mobile terminal within said cell.

57. The positioning system according to claim 54, wherein said processing means receive a dedicated value of a timing advance parameter originating from a base transceiver station of said cellular network serving said cell, which cell is currently a serving cell for said mobile terminal, for a plurality of positions of said mobile terminal in said cell, and wherein said processing means for determining geographical information estimate said cell range based on the length of a propagation path of signals transmitted from said base transceiver station to said mobile station at a position associated to the largest value of said timing advance parameter, which length of propagation path is indicated by said largest value of said timing advance parameter.

58. The positioning system according to claim 47, fuirther comprising a receiver for receiving satellite signals, wherein said processing means calculate said at least one position of said mobile terminal in a cell of said cellular network based on satellite signals received by said receiver.

59. The positioning system according to claim 47, comprising processing means for updating said database when new information on a specific cell is provided by said processing means for determining geographical information when said mobile terminal reenters said cell.

60. The positioning system according to claim 59, wherein said processing means for calculating at least one position of said mobile terminal calculate at least one position of said mobile terminal when said mobile terminal reenters said cell, wherein said processing means for determining geographical information on said cell provide an estimate of the cell coordinates and an estimate of the cell radius together with an identification of said cell for storage in said database, and wherein said processing means for determining geographical information on said cell

determine a circular area of which the center is given by said estimated cell coordinates and of which the radius is given by said estimated cell radius;

determine whether at least one position of said mobile terminal in said cell which was calculated after said mobile terminal reentered said cell lies outside of said determined circular area;

connect a calculated position which is determined to lie outside of said determined circular area with the center of said circular area by a straight line and extend said straight line to the border of said circular area;

determine new cell coordinates to correspond to the mean of the coordinates of the endpoints of said straight line; and

estimate a new cell radius to correspond to one half of the length of said straight line.

61. The positioning system according to claim 60, wherein said processing means for calculating at least one position of said mobile terminal calculate a plurality of positions of said mobile terminal when said mobile terminal reenters said cell, and wherein said processing means for determining geographical information on said cell determine which one of a plurality of positions which were calculated when said mobile terminal reentered said cell and which are determined to lie outside of said determined circular area is most distant to said center of said circular area and employ said most distant calculated position as starting point for said straight line.

62. The positioning system according to claim 47, wherein said identification of a cell is composed of values of hierarchical components, wherein said database has a hierarchical structure which comprises a dedicated level for each hierarchical component of said identification, each level comprising nodes representing a different value of a specific hierarchical component, wherein nodes of the highest level of said hierarchical structure are connected in a chained line, a first node of said highest level nodes being accessible via a root node, wherein each node of a specific level except for the lowest level points to a chained line of nodes in the respective subordinate level, and wherein each node of the lowest level comprises data with geographical information.

63. The positioning system according to claim 62, comprising processing means for inserting provided geographical information on a new cell into said database such that a respective node representing a value of a hierarchical component identifying said cell which is not yet comprised in said hierarchical structure is inserted at the beginning of the respective line of nodes.

64. The positioning system according to claim 62, comprising processing means for extracting data from said database, wherein in case said processing means extract geographical information for a specific cell from said database, said processing means shift those nodes representing the values of the hierarchical components of the identification of said cell to the first place in their respective line.

65. The positioning system according to claim 47, wherein said database comprises a hash table for storing geographical information for a plurality of cells, said positioning system comprising processing means for determining a slot in said table for storing said geographical information for a specific cell by applying a hash function to an identification of said specific cell.

66. The positioning system according to claim 65, wherein in case said processing means for determining a slot determine a slot of said hash table for storing geographical information on a specific cell which is already used for storing geographical information on another cell, said processing means store said geographical information on said specific cell in a slot of a list of additional slots to which a pointer associated to said determined slot is pointing.

67. The positioning system according to claim 47, wherein said mobile terminal comprises said processing means for determining geographical information.

68. The positioning system according to claim 58, wherein said mobile terminal comprises said receiver.

69. The positioning system according to claim 58, wherein said mobile terminal is connected to said receiver.

70. The positioning system according to claim 47, wherein said mobile terminal comprises said database.

71. The positioning system according to claim 58, wherein said receiver comprises said processing means for calculating at least one position of said mobile terminal in a cell.

72. The positioning system according to claim 47, comprising a network unit accessible by a mobile terminal, which network unit includes said processing means for determining geographical information.

73. The positioning system according to claim 47, comprising a network unit accessible by a mobile terminal, which network unit includes said processing means for calculating at least one position of a mobile terminal.

74. The positioning system according to claim 47, comprising a network unit accessible by a mobile terminal, which network unit includes said database.