Method and apparatus for delivering assistance data from a server to a device identifying virtual access points

• US 9,588,216 B2
• Filed: 11/10/2014
• Issued: 03/07/2017
• Est. Priority Date: 11/12/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Do, Ju-yong, Zhang, Gengsheng, Garin, Lionel Jacques, Venkatraman, Sai Pradeep, Liu, Weiyi, Raman, Sundar
• Primary Examiner(s): Milord, Marceau
• Application Number:
  US14/537,744
• Publication Number:
  US 20150133154A1
• Time in Patent Office: 848 Days
• Field of Search: 455/456.1, 455/434, 455/404.2, 455/457
• US Class Current: 1/1
• CPC Class Codes: G01S 5/0236 Assistance data, e.g. base station almanac
• CPC Class Codes: G01S 5/02524 Creating or updating the radio-map
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Methods and apparatus for processing positioning assistance data are provided. An exemplary method includes receiving, from a positioning server, virtual access point (VAP) data including a list of unique identifiers, and determining a location of a mobile device by using the VAP. The VAP data indicates that the unique identifiers included on the list identify signals originating from the same physical access point. The unique identifiers can be MAC addresses. In an example, the location determining the can include actively scanning a signal identified by a unique identifier on the list and not actively scanning a different signal identified by a different unique identifier also on the list. Not scanning the other MAC addresses that are on the access point'"'"'s list and assigned to the mobile device keeps the mobile device from performing duplicative scanning that wastes time, processor cycles, and energy.

Claims

1. A method for processing position assistance data by a mobile device, comprising:

receiving virtual access point (VAP) data including a unique identifier for a physical access point (AP) and a list of unique identifiers for one or more virtual APs from a positioning server, the VAP data indicating that the unique identifiers for the one or more virtual APs included on the list identify signals originating from the physical AP, wherein the VAP data comprises;

a field representative of an AP base media access control (MAC) address of the physical AP; and

an other field representative of an AP MAC address corresponding to a respective virtual AP belonging to the physical AP, wherein the other field repeats a number of times corresponding to a number of virtual APs that belong to the physical AP; and

determining a location of the mobile device, wherein the mobile device uses the VAP data when determining the location.

2. The method of claim 1, further comprising sending a position assistance data request message to a positioning server.

3. The method of claim 2, wherein the request message includes a coarse position including latitude, longitude, and altitude of the mobile device.

4. The method of claim 2, wherein the request message includes a venue ID of a venue in which the mobile device is located.

5. The method of claim 2, wherein the request message includes a WiFi scan list of the mobile device.

6. The method of claim 1, wherein the unique identifiers are media access control (MAC) addresses.

7. The method of claim 1, wherein the determining the location of the mobile device includes actively scanning a signal identified by a unique identifier included on the list and not actively scanning a different signal identified by a different unique identifier also included on the list.

8. The method of claim 1, wherein the determining the location of the mobile device includes computing a signal characteristic for the AP by averaging corresponding signal measurement values for more than one signal, each signal associated with a different unique identifier included on the list.

9. The method of claim 8, wherein the signal characteristic includes signal strength, range, or a combination of both.

10. The method of claim 1, further comprising receiving assistance data (AD) including one or more heatmaps associated with the unique identifiers included on the list.

11. The method of claim 10, wherein the one or more heatmaps include a baseline heatmap with an offset associated with each of the unique identifiers included on the list.

12. The method of claim 1, wherein the determining the location of the mobile device includes venue disambiguation.

13. The method of claim 12, further comprising:

passively scanning AP beacons the mobile device detects; and

determining, based on the AP beacons the mobile device detects, that the mobile device is in an area associated with a specific location context identifier.

14. The method of claim 12, wherein the venue disambiguation is based on a number of APs meeting a criteria, and not on a number of unique identifiers.

15. The method of claim 1, further comprising:

receiving a list of media access control (MAC) addresses from the positioning server;

identifying a MAC address that is both on the received list of MAC addresses and used by the mobile device; and

scanning only one of the MAC addresses on the received list for the position assistance data, and not scanning any of the other MAC addresses on the received list.

16. The method of claim 1, further comprising:

identifying one or more media access control (MAC) addresses that are both on the list of unique identifiers and observed by the mobile device, wherein the unique identifiers in the list of unique identifiers are MAC addresses; and

performing ranging with or measuring strength of a signal received from the AP associated with the one or more of the MAC addresses on the list of unique identifiers, but not scanning all MAC addresses on the list of unique identifiers.

17. The method of claim 1, wherein the VAP data further comprises a NUM_MAC field indicating the number of virtual APs belonging to the physical AP.

18. A mobile device, comprising:

a memory; and

a processor coupled to the memory and configured to;

receive virtual access point (VAP) data including a unique identifier for a physical access point (AP) and a list of unique identifiers for one or more virtual APs from a positioning server, the VAP data indicating that the unique identifiers for the one or more virtual APs included on the list identify signals originating from the physical AP, wherein the VAP data comprises;

a field representative of an AP base media access control (MAC) address of the physical AP; and

an other field representative of an AP MAC address corresponding to a respective virtual AP belonging to the physical AP, wherein the other field repeats a number of times corresponding to a number of virtual APs that belong to the physical AP; and

determine a location of the mobile device, wherein the processor uses the VAP data when determining the location.

19. The mobile device of claim 18, wherein the processor is further configured to cause the mobile device to send a position assistance data request to a positioning server.

20. The mobile device of claim 19, wherein the request message includes a coarse position including latitude, longitude, and altitude of the mobile device.

21. The mobile device of claim 19, wherein the request message includes a venue ID of a venue in which the mobile device is located.

22. The mobile device of claim 19, wherein the request message includes a WiFi scan list of the mobile device.

23. The mobile device of claim 18, wherein the unique identifiers are media access control (MAC) addresses.

24. The mobile device of claim 18, wherein the processor configured to determine the location of the mobile device includes actively scanning a signal identified by a unique identifier included on the list and not actively scanning a different signal identified by a different unique identifier also included on the list.

25. The mobile device of claim 18, wherein the processor configured to determine the location of the mobile device includes computing a signal characteristic for the AP by averaging corresponding signal measurement values for more than one signal, each signal associated with a different unique identifier included on the list.

26. The mobile device of claim 25, wherein the signal characteristic includes signal strength, range, or a combination of both.

27. The mobile device of claim 18, wherein the processor is further configured to receive assistance data (AD) including one or more heatmaps associated with the unique identifiers included on the list.

28. The mobile device of claim 27, wherein the one or more heatmaps include a baseline heatmap with an offset associated with each of the unique identifiers included on the list.

29. The mobile device of claim 18, wherein the determining a location of the mobile device includes venue disambiguation.

30. The mobile device of claim 29, wherein the processor is further configured to:

cause the mobile device to passively scan AP beacons the mobile device detects; and

determine, based on the AP beacons the mobile device detects, that the mobile device is in an area associated with a specific location context identifier.

31. The mobile device of claim 29, wherein the venue disambiguation is based on a number of APs meeting a criteria, and not on a number of unique identifiers.

32. The mobile device of claim 18, wherein the processor is further configured to:

receive a list of media access control (MAC) addresses from the positioning server;

identify a MAC address that is both on the received list of MAC addresses and used by the mobile device; and

scan only one of the MAC addresses on the received list for position assistance data, and not scanning any of the other MAC addresses on the received list.

33. The mobile device of claim 18, wherein the processor is further configured to:

identify one or more media access control (MAC) addresses that are both on the list of unique identifiers and observed by the mobile device, wherein the unique identifiers in the list of unique identifiers are MAC addresses; and

perform ranging with or measuring strength of a signal received from the AP associated with the one or more of the MAC addresses on the list of unique identifiers, but not scanning all of the MAC addresses on the list of unique identifiers.

34. The mobile device of claim 18, wherein the VAP data further comprises a NUM_MAC field indicating the number of virtual APs belonging to the physical AP.

35. A non-transitory computer-readable medium, comprising processor-executable instructions stored thereon to be retrieved and executed by one or more processors, the processor-executable instructions including instructions to:

receive virtual access point (VAP) data at a mobile device, the VAP data including a unique identifier for a physical access point (AP) and a list of unique identifiers or one or more virtual APs from a positioning server, the VAP data indicating that the unique identifiers for the one or more virtual APs included on the list identify signals originating from the physical AP, wherein the VAP data comprises;

a field representative of an AP base media access control (MAC) address of the physical AP; and

an other field representative of an AP MAC address corresponding to a respective virtual AP belonging to the physical AP, wherein the other field repeats a number of times corresponding to a number of virtual APs that belong to the physical AP; and

determine a location of the mobile device, wherein the mobile device uses the VAP data when determining the location.

36. The non-transitory computer-readable medium of claim 35, the processor-executable instructions further include instructions to send a position assistance data request to a positioning server.

37. The non-transitory computer-readable medium of claim 36, wherein the request message includes a coarse position including latitude, longitude, and altitude of the mobile device.

38. The non-transitory computer-readable medium of claim 36, wherein the request message includes a venue ID of a venue in which the mobile device is located.

39. The non-transitory computer-readable medium of claim 36, wherein the request message includes a WiFi scan list of the mobile device.

40. The non-transitory computer-readable medium of claim 35, wherein the unique identifiers are media access control (MAC) addresses.

41. The non-transitory computer-readable medium of claim 35, wherein the instructions to determine the location of the mobile device include instructions to actively scan a signal identified by a unique identifier included on the list without actively scanning a different signal identified by a different unique identifier also included on the list.

42. The non-transitory computer-readable medium of claim 35, wherein the instructions to determine the location of the mobile device include instructions to compute a signal characteristic for the AP by averaging corresponding signal measurement values for more than one signal, each signal associated with a different unique identifier included on the list.

43. The non-transitory computer-readable medium of claim 42, wherein the signal characteristic includes signal strength, range, or a combination of both.

44. The non-transitory computer-readable medium of claim 35, wherein the processor-executable instructions further include instructions to receive assistance data (AD) including one or more heatmaps associated with the unique identifiers included on the list.

45. The non-transitory computer-readable medium of claim 44, wherein the one or more heatmaps include a baseline heatmap with an offset associated with each of the unique identifiers included on the list.

46. The non-transitory computer-readable medium of claim 35, wherein the determining a location of the mobile device includes venue disambiguation.

47. The non-transitory computer-readable medium of claim 46, wherein the processor-executable instructions further include instructions to cause the one or more processors to:

passively scan AP beacons the mobile device detects; and

determine, based on the AP beacons the mobile device detects, that the mobile device is in an area associated with a specific location context identifier.

48. The non-transitory computer-readable medium of claim 46, wherein the venue disambiguation is based on a number of APs meeting a criteria, and not on a number of unique identifiers.

49. The non-transitory computer-readable medium of claim 35, wherein the processor-executable instructions further include instructions to:

receive a list of media access control (MAC) addresses from the positioning server;

identify a MAC address that is both on the received list of MAC addresses and used by the mobile device; and

scan only one of the MAC addresses on the received list for position assistance data, and not scan any of the other MAC addresses on the received list.

50. The non-transitory computer-readable medium of claim 35, wherein the processor-executable instructions further include instructions to:

identify one or more media access control (MAC) addresses that are both on the list of unique identifiers and observed by the mobile device, wherein the unique identifiers in the list of unique identifiers are MAC addresses; and

perform ranging with or measuring strength of a signal received from the AP associated with the one or more of the MAC addresses on the list of unique identifiers, but not scanning all of the MAC addresses on the list of unique identifiers.

51. A mobile device configured to process position assistance data, comprising:

means for receiving virtual access point (VAP) data including a unique identifier for a physical access point (AP) and a list of unique identifiers for one or more virtual APs from a positioning server, the VAP data indicating that the unique identifiers for the one or more virtual APs included on the list identify signals originating from the physical AP, wherein the VAP data comprises;

a field representative of an AP base media access control (MAC) address of the physical AP; and

an other field representative of an AP MAC address corresponding to a respective virtual AP belonging to the physical AP, wherein the other field repeats a number of times corresponding to a number of virtual APs that belong to the physical AP; and

means for determining a location of the mobile device, wherein the mobile device uses the VAP data when determining the location.

52. The mobile device of claim 51, further comprising means for sending a position assistance data request to a positioning server.

53. The mobile device of claim 52, wherein the request message includes a coarse position including latitude, longitude, and altitude of the mobile device.

54. The mobile device of claim 52, wherein the request message includes a venue ID of a venue in which the mobile device is located.

55. The mobile device of claim 52, wherein the request message includes a WiFi scan list of the mobile device.

56. The mobile device of claim 51, wherein the unique identifiers are media access control (MAC) addresses.

57. The mobile device of claim 51, wherein the means for determining the location of the mobile device includes means for actively scanning a signal identified by a unique identifier included on the list and not actively scanning a different signal identified by a different unique identifier also included on the list.

58. The mobile device of claim 51, wherein the means for determining the location of the mobile device includes means for computing a signal characteristic for the AP by averaging corresponding signal measurement values for more than one signal, each signal associated with a different unique identifier included on the list.

59. The mobile device of claim 58, wherein the signal characteristic includes signal strength, range, or a combination of both.

60. The mobile device of claim 51, further comprising means for receiving assistance data (AD) including one or more heatmaps associated with the unique identifiers included on the list.

61. The mobile device of claim 60, wherein the one or more heatmaps include a baseline heatmap with an offset associated with each of the unique identifiers included on the list.

62. The mobile device of claim 51, wherein the means for determining the location of the mobile device includes means for venue disambiguation.

63. The mobile device of claim 62, further comprising:

means for passively scanning AP beacons the mobile device detects; and

means for determining, based on the AP beacons the mobile device detects, that the mobile device is in an area associated with a specific location context identifier.

64. The mobile device of claim 62, wherein the venue disambiguation is based on a number of APs meeting a criteria, and not on a number of unique identifiers.

65. The mobile device of claim 51, further comprising:

means for receiving a list of media access control (MAC) addresses from the positioning server;

means for identifying a MAC address that is both on the received list of MAC addresses and used by the mobile device; and

means for scanning only one of the MAC addresses on the received list for the position assistance data, and not scanning any of the other MAC addresses on the received list.

66. The mobile device of claim 51, further comprising:

means for identifying one or more media access control (MAC) addresses that are both on the list of unique identifiers and observed by the mobile device, wherein the unique identifiers in the list of unique identifiers are MAC addresses; and

means for performing ranging with or measuring strength of a signal received from the AP associated with the one or more of the MAC addresses on the list of unique identifiers, but not scanning all of the MAC addresses on the list of unique identifiers.

67. A method for providing position assistance data from a positioning server, comprising:

receiving a position assistance data request message from a mobile device; and

transmitting to the mobile device, in response to the position assistance data request message, virtual access point (VAP) data including a unique identifier for a physical access point (AP) and a list of unique identifiers for one or more virtual APs, the VAP data indicating that the unique identifiers for the one or more virtual APs included on the list identify signals originating from the physical AP, wherein the VAP data comprises;

a field representative of an AP base media access control (MAC) address of the physical AP; and

an other field representative of an AP MAC address corresponding to a respective virtual AP belonging to the physical AP, wherein the other field repeats a number of times corresponding to a number of virtual APs that belong to the physical AP.

68. The method of claim 67, wherein the position assistance data request message includes a coarse position including latitude, longitude, and altitude of the mobile device, and further comprising finding venues nearest to the mobile device'"'"'s position, combining all matching venues into a venue list, and finding assistance data for the identified venues.

69. The method of claim 67, wherein the position assistance data request message includes a venue ID of a venue in which the mobile device is located, and further comprising finding venues with a matching venue ID, combining all matching venues into a venue list, and finding assistance data for the identified venues.

70. The method of claim 67, wherein the position assistance data request message includes a WiFi scan list of the mobile device, and the method further comprising finding matching media access control (MAC) addresses from an access point database, removing duplicate VAP data, finding venues nearest to the mobile device, combining all matching venues into a venue list, and finding assistance data for the identified venues.

71. The method of claim 67, wherein the unique identifiers are media access control (MAC) addresses.

72. The method of claim 67, further comprising transmitting assistance data (AD) including one or more heatmaps associated with the unique identifiers included on the list.

73. The method of claim 72, wherein the one or more heatmaps include a baseline heatmap with an offset associated with each of the unique identifiers included on the list.

74. The method of claim 67, wherein the VAP data further comprises a NUM_MAC field indicating the number of virtual APs belonging to the physical AP.

75. A positioning server, comprising:

a memory; and

a processor coupled to the memory and configured to;

receive a position assistance data request message from a mobile device; and

transmit to the mobile device, in response to the position assistance data request message, virtual access point (VAP) data including a unique identifier for a physical access point (AP) and a list of unique identifiers for one or more virtual APs, the VAP data indicating that the unique identifiers for the one or more virtual APs included on the list identify signals originating from the physical AP, wherein the VAP data comprises;

a field representative of an AP base media access control (MAC) address of the physical AP; and

an other field representative of an AP MAC address corresponding to a respective virtual AP belonging to the physical AP, wherein the other field repeats a number of times corresponding to a number of virtual APs that belong to the physical AP.

76. The positioning server of claim 75, wherein the position assistance data request message includes a coarse position including latitude, longitude, and altitude of the mobile device, and the processor is further configured to find venues nearest to the mobile device'"'"'s position, combine all matching venues into a venue list, and find assistance data for the identified venues.

77. The positioning server of claim 75, wherein the position assistance data request message includes a venue ID of a venue in which the mobile device is located, and the processor is further configured to find venues with a matching venue ID, combine all matching venues into a venue list, and find assistance data for the identified venues.

78. The positioning server of claim 75, wherein the position assistance data request message includes a WiFi scan list of the mobile device, and the processor is further configured to find matching media access control (MAC) addresses from an access point database, remove duplicate VAP data, find venues nearest to the mobile device, combine all matching venues into a venue list, and find assistance data for the identified venues.

79. The positioning server of claim 75, wherein the unique identifiers are media access control (MAC) addresses.

80. The positioning server of claim 75, wherein the processor is further configured to transmit assistance data (AD) including one or more heatmaps associated with the unique identifiers included on the list.

81. The positioning server of claim 80, wherein the one or more heatmaps include a baseline heatmap with an offset associated with each of the unique identifiers included on the list.

82. The positioning server of claim 75, wherein the VAP data further comprises a NUM_MAC field indicating the number of virtual APs belonging to the physical AP.

83. A non-transitory computer-readable medium, comprising processor-executable instructions stored thereon to be retrieved and executed by one or more processors, the processor-executable instructions including instructions to:

receive a position assistance data request message from a mobile device; and

transmit to the mobile device, in response to the position assistance data request message, virtual access point (VAP) data including a unique identifier for a physical access point (AP) and a list of unique identifiers for one or more virtual APs, the VAP data indicating that the unique identifiers for the one or more virtual APs included on the list identify signals originating from the physical AP, wherein the VAP data comprises;

a field representative of an AP base media access control (MAC) address of the physical AP; and

an other field representative of an AP MAC address corresponding to a respective virtual AP belonging to the physical AP, wherein the other field repeats a number of times corresponding to a number of virtual APs that belong to the physical AP.

84. The non-transitory computer-readable medium of claim 83, wherein the position assistance data request message includes a coarse position including latitude, longitude, and altitude of the mobile device, and the processor-executable instructions include instructions to find venues nearest to the mobile device'"'"'s position, combine all matching venues into a venue list, and find assistance data for the identified venues.

85. The non-transitory computer-readable medium of claim 83, wherein the position assistance data request message includes a venue ID of a venue in which the mobile device is located, and the processor-executable instructions include instructions to find venues with a matching venue ID, combine all matching venues into a venue list, and find assistance data for the identified venues.

86. The non-transitory computer-readable medium of claim 83, wherein the position assistance data request message includes a WiFi scan list of the mobile device, and the processor-executable instructions include instructions to find matching media access control (MAC) addresses from an access point database, remove duplicate VAP data, find venues nearest to the mobile device, combine all matching venues into a venue list, and find assistance data for the identified venues.

87. The non-transitory computer-readable medium of claim 83, wherein the unique identifiers are media access control (MAC) addresses.

88. The non-transitory computer-readable medium of claim 83, wherein the processor-executable instructions further include instructions to cause the one or more processors to transmit assistance data (AD) including one or more heatmaps associated with the unique identifiers included on the list.

89. The non-transitory computer-readable medium of claim 88, wherein the one or more heatmaps include a baseline heatmap with an offset associated with each of the unique identifiers included on the list.

90. A positioning server, comprising:

means for receiving a position assistance data request message from a mobile device; and

means for transmitting to the mobile device, in response to the position assistance data request message, virtual access point (VAP) data including a unique identifier for a physical access point (AP) and a list of unique identifiers for one or more virtual APs, the VAP data indicating that the unique identifiers for the one or more virtual APs included on the list identify signals originating from the physical AP, wherein the VAP data comprises;

a field representative of an AP base media access control (MAC) address of the physical AP; and

an other field representative of an AP MAC address corresponding to a respective virtual AP belonging to the physical AP, wherein the other field repeats a number of times corresponding to a number of virtual APs that belong to the physical AP.

91. The positioning server of claim 90, wherein the position assistance data request message includes a coarse position including latitude, longitude, and altitude of the mobile device, and further comprising means for finding venues nearest to the mobile device'"'"'s position, means for combining all matching venues into a venue list, and means for finding assistance data for the identified venues.

92. The positioning server of claim 90, wherein the position assistance data request message includes a venue ID of a venue in which the mobile device is located, and further comprising means for finding venues with a matching venue ID, means for combining all matching venues into a venue list, and means for finding assistance data for the identified venues.

93. The positioning server of claim 90, wherein the position assistance data request message includes a WiFi scan list of the mobile device, and further comprising means for finding matching media access control (MAC) addresses from an access point database, means for removing duplicate VAP data, finding venues nearest to the mobile device, means for combining all matching venues into a venue list, and means for finding assistance data for the identified venues.

94. The positioning server of claim 90, wherein the unique identifiers are media access control (MAC) addresses.

95. The positioning server of claim 90, further comprising means for transmitting assistance data including one or more heatmaps associated with the unique identifiers included on the list.

96. The positioning server of claim 95, wherein the one or more heatmaps include a baseline heatmap with an offset associated with each of the unique identifiers included on the list.

97. A method for performing maintenance at a positioning server, comprising:

retrieving assistance data (AD) including heatmaps from an AD database;

reducing AD size by keeping only one heatmap per physical access point and removing redundant heatmaps that previously existed for individual virtual access points associated with the physical access point;

determining if the virtual access points have individual heatmaps; and

estimating a transmit power difference across virtual access points belonging to the same physical access point and adding data describing the transmit power difference data to the AD database.

98. A method for performing maintenance at a positioning server, comprising:

retrieving assistance data (AD) including heatmaps from an AD database;

reducing AD size by keeping only one heatmap per physical access point and removing redundant heatmaps that previously existed for individual virtual access points associated with the physical access point;

storing new access point data in a WiFi access point database, if a virtual access point list received by a server does not have media access control (MAC) addresses that match those stored in the WiFi access point database and has information for AD generation;

creating a heatmap for the newly stored access point data; and

storing the heatmap into the AD database.

99. A positioning server, comprising:

a memory; and

a processor coupled to the memory and configured to;

retrieve assistance data (AD) including heatmaps from an AD database;

reduce AD size by keeping only one heatmap per physical access point and removing redundant heatmaps that previously existed for individual virtual access points associated with the physical access point;

determine if the virtual access points have individual heatmaps; and

estimate a transmit power difference across virtual access points belonging to the same physical access point and adding data describing the transmit power difference data to the AD database.

100. A positioning server, comprising:

a memory; and

a processor coupled to the memory and configured to;

retrieve assistance data (AD) including heatmaps from an AD database;

reduce AD size by keeping only one heatmap per physical access point and removing redundant heatmaps that previously existed for individual virtual access points associated with the physical access point;

store new access point data in a WiFi access point database, if a virtual access point list received by a server does not have media access control (MAC) addresses that match those stored in the WiFi access point database and has information for AD generation;

create a heatmap for the new access point data; and

store the heatmap into the AD database.

101. A non-transitory computer-readable medium, comprising processor-executable instructions stored thereon to be retrieved and executed by one or more processors, the processor-executable instructions including instructions to:

retrieve assistance data (AD) including heatmaps from an AD database;

reduce AD size by keeping only one heatmap per physical access point and removing redundant heatmaps that previously existed for individual virtual access points associated with the physical access point;

determine if the virtual access points have individual heatmaps; and

estimate a transmit power difference across virtual access points belonging to the same physical access point and adding data describing the transmit power difference data to the AD database.

102. A non-transitory computer-readable medium, comprising processor-executable instructions stored thereon to be retrieved and executed by one or more processors, the processor-executable instructions including instructions to:

retrieve assistance data (AD) including heatmaps from an AD database;

reduce AD size by keeping only one heatmap per physical access point and removing redundant heatmaps that previously existed for individual virtual access points associated with the physical access point;

store new access point data in a WiFi access point database, if a virtual access point list received by a server does not have media access control (MAC) addresses that match those stored in the WiFi access point database and has information for AD generation;

create a heatmap for the newly stored access point data; and

store the heatmap into the AD database.

103. A positioning server, comprising:

means for retrieving assistance data (AD) including heatmaps from an AD database;

means for reducing AD size by keeping only one heatmap per physical access point and removing redundant heatmaps that previously existed for individual virtual access points associated with the physical access point;

means for determining if the virtual access points have individual heatmaps; and

means for estimating a transmit power difference across virtual access points belonging to the same physical access point and adding data describing the transmit power difference data to the AD database.

104. A positioning server, comprising:

means for retrieving assistance data (AD) including heatmaps from an AD database;

means for reducing AD size by keeping only one heatmap per physical access point and removing redundant heatmaps that previously existed for individual virtual access points associated with the physical access point;

means for storing new access point data in a WiFi access point database, if a virtual access point list received by a server does not have media access control (MAC) addresses that match those stored in the WiFi access point database and has information for AD generation;

means for creating a heatmap for the newly stored access point data; and

means for storing the heatmap into the AD database.