ACCESS POINT (AP) TO ACCESS POINT (AP) RANGING FOR PASSIVE LOCATIONING

• US 20180249437A1
• Filed: 02/22/2018
• Published: 08/30/2018
• Est. Priority Date: 02/27/2017
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Lindskog, Erik David, Kakani, Naveen Kumar, Raissinia, Alireza
• Application Number:
  US15/902,289
• Publication Number:
  US 20180249437A1
• Time in Patent Office: Days
• CPC Class Codes: G01S 13/825 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 5/0226 Transmitters
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for performing ranging operations. In one aspect, an apparatus negotiates a passive ranging schedule between an initiator device and a number of responder devices. The passive ranging schedule indicates a time prior to a selected target beacon transmission time (TBTT) at which the ranging operation is to commence. The apparatus announces the passive ranging schedule to at least one or more passive listening devices, commences the ranging operation at the indicated time by exchanging a number of frames between the initiator device and the number of responder devices, and completes the exchange of frames prior to the selected TBTT.

Claims

1. A method of performing a ranging operation, comprising:

negotiating a passive ranging schedule between an initiator device and a number of responder devices, the passive ranging schedule indicating a time prior to a selected target beacon transmission time (TBTT) at which the ranging operation is to commence;

announcing the passive ranging schedule to the number of responder devices and to a number of passive listening devices;

commencing the ranging operation at the indicated time by exchanging a number of frames between the initiator device and the number of responder devices;

facilitating a passive positioning operation for each of the passive listening devices using the exchanged frames; and

completing the exchange of frames prior to the selected TBTT.

2. The method of claim 1, wherein the passive ranging schedule comprises a participant field including at least one of an identity of each device participating in the ranging operation, an indication of whether each of the identified participant devices is an access point or a client device, and an indication of whether each of the identified participant devices is to operate as the initiator device or as one of the responder devices.

3. The method of claim 1, wherein the passive ranging schedule comprises a parameters field including at least one of a type of frames to be exchanged during the ranging operation, a number of antennas to be used by the responder devices during the ranging operation, a frequency bandwidth to be used for transmitting the frames, a wireless channel to be used for the ranging operation, a capability to capture timestamps of the frames, and a capability to estimate angle information of the frames.

4. The method of claim 1, wherein the passive ranging schedule comprises a synchronization field including mappings between a clock domain of the initiator device and clock domains of each of the responder devices, wherein the mappings comprise at least clock offset values between the clock domain of the initiator device and the clock domains of the responder devices.

5. The method of claim 1, wherein the announcing comprises:

broadcasting the passive ranging schedule in every N^th beacon frame, wherein each beacon frame includes a counter value indicating which of the beacon frames includes the passive ranging schedule, and wherein N is an integer greater than one.

6. The method of claim 1, wherein the frames are exchanged according to a fine timing measurement (FTM) protocol and comprise a number of multi-user null data packets (MU-NDPs), and at least one of the MU-NDPs comprises an uplink (UL) MU-NDP transmitted from multiple antennas of a respective one of the responder devices.

7. The method of claim 1, wherein exchanging the number of frames comprises:

transmitting, to the responder devices, a downlink null data packet (DL NDP) including a plurality of sounding sequences from which a corresponding plurality of round trip time (RTT) values are obtained;

transmitting a trigger frame to the responder devices;

receiving an uplink multi-user null data packet (UL MU-NDP) from each of the responder devices identified by the trigger frame; and

transmitting, to the responder devices, a beacon frame including timing information indicating time of arrival (TOA) values of the UL MU-NDPs received at the initiator device and indicating a time of departure (TOD) value of the DL NDP transmitted from the initiator device.

8. The method of claim 1, wherein exchanging the number of frames comprises:

transmitting a trigger frame to the responder devices;

receiving an uplink multi-user null data packet (UL MU-NDP) from each of the responder devices identified by the trigger frame;

transmitting a downlink null data packet (DL NDP) to the responder devices; and

transmitting, to the responder devices, a downlink feedback (DL FB) frame including timing information indicating time of arrival (TOA) values of the UL MU-NDPs received at the initiator device and indicating a time of departure (TOD) value of the DL NDP transmitted from the initiator device.

9. The method of claim 8, wherein the DL FB frame further includes at least one of angle of departure (AoD) information of the UL MU-NDPs transmitted from the responder devices, location information of the initiator device, and location information of one or more of the responder devices.

10. The method of claim 8, wherein the DL NDP further comprises a null data packet announcement (NDPA).

11. The method of claim 8, wherein exchanging the number of frames further comprises:

receiving, from each of the responder devices, an uplink multi-user (UL MU) frame including timing information indicating TOD values of the UL MU-NDPs transmitted from the responder devices and indicating TOA values of the DL NDP arriving at the responder devices.

12. The method of claim 11, wherein facilitating the passive positioning operation comprises:

enabling the passive listening device to determine a differential distance between itself and each of a pair of the initiator device and one of the responder devices based on the timing information included in the DL FB frame, the timing information included in the UL MU frames transmitted from the pair of the responder devices, and TOA values of the UL MU-NDPs at the passive listening device.

13. An apparatus for performing a ranging operation, comprising:

one or more transceivers configured to exchange wireless signals with one or more wireless devices;

one or more processors; and

a memory comprising instructions that, when executed by the one or more processors, cause the apparatus to;

negotiate a passive ranging schedule between an initiator device and a number of responder devices, the passive ranging schedule indicating a time prior to a selected target beacon transmission time (TBTT) at which the ranging operation is to commence;

announce the passive ranging schedule to the number of responder devices and to a number of passive listening devices;

commence the ranging operation at the indicated time by exchanging a number of frames between the initiator device and the number of responder devices;

facilitate a passive positioning operation for each of the passive listening devices using the exchanged frames; and

complete the exchange of frames prior to the selected TBTT.

14. The apparatus of claim 13, wherein the passive ranging schedule comprises a participant field including at least one of an identity of each device participating in the ranging operation, an indication of whether each of the identified participant devices is an access point or a client device, and an indication of whether each of the identified participant devices is to operate as the initiator device or as one of the responder devices.

15. The apparatus of claim 13, wherein the passive ranging schedule comprises a parameters field including at least one of a type of frames to be exchanged during the ranging operation, a number of antennas to be used by the responder devices during the ranging operation, a frequency bandwidth to be used for transmitting the frames, a wireless channel to be used for the ranging operation, a capability to capture timestamps of the frames, and a capability to estimate angle information of the frames.

16. The apparatus of claim 13, wherein the passive ranging schedule comprises a synchronization field including mappings between a clock domain of the initiator device and clock domains of each of the responder devices, wherein the mappings comprise at least clock offset values between the clock domain of the initiator device and the clock domains of the responder devices.

17. The apparatus of claim 13, wherein execution of the instructions for announcing the passive ranging schedule causes the apparatus to:

broadcast the passive ranging schedule in every N^th beacon frame, wherein each beacon frame includes a counter value indicating which of the beacon frames includes the passive ranging schedule, and wherein N is an integer greater than one.

18. The apparatus of claim 13, wherein the frames are exchanged according to a fine timing measurement (FTM) protocol and comprise a number of multi-user null data packets (MU-NDPs), and at least one of the MU-NDPs comprises an uplink (UL) MU-NDP transmitted from multiple antennas of a respective one of the responder devices.

19. The apparatus of claim 13, wherein execution of the instructions for exchanging the number of frames causes the apparatus to:

transmit, to the responder devices, a downlink null data packet (DL NDP) including a plurality of sounding sequences from which a corresponding plurality of round trip time (RTT) values are obtained;

transmit a trigger frame to the responder devices;

receive an uplink multi-user null data packet (UL MU-NDP) from each of the responder devices identified by the trigger frame; and

transmit, to the responder devices, a beacon frame including timing information indicating time of arrival (TOA) values of the UL MU-NDPs received at the initiator device and indicating a time of departure (TOD) value of the DL NDP transmitted from the initiator device.

20. The apparatus of claim 13, wherein execution of the instructions for exchanging the number of frames causes the apparatus to:

transmit a trigger frame to the responder devices;

receive an uplink multi-user null data packet (UL MU-NDP) from each of the responder devices identified by the trigger frame;

transmit a downlink null data packet (DL NDP) to the responder devices; and

transmit, to the responder devices, a downlink feedback (DL FB) frame including timing information indicating time of arrival (TOA) values of the UL MU-NDPs at the initiator device and indicating a time of departure (TOD) value of the DL NDP transmitted from the initiator device.

21. The apparatus of claim 20, wherein the DL FB frame further includes at least one of angle of departure (AoD) information of the UL MU-NDPs transmitted from the responder devices, location information of the initiator device, and location information of one or more of the responder devices.

22. The apparatus of claim 20, wherein the DL NDP further comprises a null data packet announcement (NDPA).

23. The apparatus of claim 20, wherein execution of the instructions for exchanging the number of frames further causes the apparatus to:

receive, from each of the responder devices, an uplink multi-user (UL MU) frame including timing information indicating TOD values of the UL MU-NDPs transmitted from the responder devices and indicating TOA values of the DL NDP arriving at the responder devices.

24. The apparatus of claim 23, wherein execution of the instructions for facilitating the passive ranging operation causes the apparatus to:

enable the passive listening device to determine a differential distance between itself and each of a pair of the initiator device and one of the responder devices based on the timing information included in the DL FB frame, the timing information included in the UL MU frames transmitted from the pair of the responder devices, and TOA values of the UL MU-NDPs at the passive listening device.

25. A non-transitory computer-readable storage medium comprising instructions that, when executed by one or more processors of an apparatus, cause the apparatus to perform operations comprising:

negotiating a passive ranging schedule between an initiator device and a number of responder devices, the passive ranging schedule indicating a time prior to a selected target beacon transmission time (TBTT) at which the ranging operation is to commence;

announcing the passive ranging schedule to the number of responder devices and to a number of passive listening devices;

commencing the ranging operation at the indicated time by exchanging a number of frames between the initiator device and the number of responder devices;

facilitating passive positioning operations for one or more of the passive listening devices using the exchanged frames; and

completing the exchange of frames prior to the selected TBTT.

26. The non-transitory computer-readable storage medium of claim 25, wherein execution of the instructions for exchanging the number of frames causes the apparatus to perform operations further comprising:

transmitting, to the responder devices, a downlink null data packet (DL NDP) including a plurality of sounding sequences from which a corresponding plurality of round trip time (RTT) values are obtained;

transmitting a trigger frame to the responder devices;

receiving an uplink multi-user null data packet (UL MU-NDP) from each of the responder devices identified by the trigger frame; and

transmitting, to the responder devices, a beacon frame including timing information indicating time of arrival (TOA) values of the UL MU-NDPs received at the initiator device and indicating a time of departure (TOD) value of the DL NDP transmitted from the initiator device.

27. The non-transitory computer-readable storage medium of claim 25, wherein execution of the instructions for exchanging the number of frames causes the apparatus to perform operations further comprising:

transmitting a trigger frame to the responder devices;

receiving an uplink multi-user null data packet (UL MU-NDP) from each of the responder devices identified by the trigger frame;

transmitting a downlink null data packet (DL NDP) to the responder devices; and

transmitting, to the responder devices, a downlink feedback (DL FB) frame including timing information indicating time of arrival (TOA) values of the UL MU-NDPs at the initiator device and indicating a time of departure (TOD) value of the DL NDP transmitted from the initiator device.

28. The non-transitory computer-readable storage medium of claim 27, wherein execution of the instructions for exchanging the number of frames causes the apparatus to perform operations further comprising:

receiving, from each of the responder devices, an uplink multi-user (UL MU) frame including timing information indicating TOD values of the UL MU-NDPs transmitted from the responder devices and indicating TOA values of the DL NDP arriving at the responder devices.

29. The non-transitory computer-readable storage medium of claim 28, wherein execution of the instructions for facilitating the passive ranging operation causes the apparatus to perform operations further comprising:

enabling the passive listening device to determine a differential distance between itself and each of a pair of the initiator device and one of the responder devices based on the timing information included in the DL FB frame, the timing information included in the UL MU frames transmitted from the pair of the responder devices, and TOA values of the UL MU-NDPs at the passive listening device.

30. An apparatus for performing a ranging operation, comprising:

means for negotiating a passive ranging schedule between an initiator device and a number of responder devices, the passive ranging schedule indicating a time prior to a selected target beacon transmission time (TBTT) at which the ranging operation is to commence;

means for announcing the passive ranging schedule to the number of responder devices and to a number of passive listening devices;

means for commencing the ranging operation at the indicated time by exchanging a number of frames between the initiator device and the number of responder devices;

means for facilitating a passive positioning operation for each of the passive listening devices using the exchanged frames; and

means for completing the exchange of frames prior to the selected TBTT.