METHODS AND SYSTEMS FOR RANGING PROTOCOL

• US 20160080960A1
• Filed: 08/13/2015
• Published: 03/17/2016
• Est. Priority Date: 09/12/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Aldana, Carlos, Zhang, Xiaoxin
• Granted Patent: US 10,716,024 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01S 13/74 Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
• CPC Class Codes: G01S 13/787 co-operating with direction defining beacons
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04L 43/0858 One way delays
• CPC Class Codes: H04L 43/106 using time related information in packets, e.g. by adding timestamps
• 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

Disclosed are systems, methods and devices for measuring a range between wireless devices using an exchange of messages between devices. For example, wireless transceiver devices may exchange messages transmitted in a wireless communications link to measure a time of flight. Based, at least in part, on the measured time of flight, a location of one of the wireless transceiver devices may be estimated.

Claims

1. At a first wireless transceiver device, a method comprising:

receiving a plurality of fine timing measurement (FTM) messages from a second wireless transceiver device, the plurality of FTM messages having been transmitted by the second wireless transceiver device in response to receipt, at the second wireless transceiver device, of an FTM request message, at least one of the plurality of FTM messages comprising a time stamp indicating a transmission time of a previously transmitted FTM message; and

computing a time of flight based, at least in part, on the time stamp and a time of receipt of the previously transmitted FTM message.

2. The method of claim 1, wherein computing the time of flight further comprises:

synchronizing the time stamp to the time of receipt based, at least in part, on a first clock signal maintained at the first wireless transceiver device synchronized to a second clock signal maintained at the second wireless transceiver device; and

subtracting the synchronized time stamp from the time of receipt.

3. The method of claim 2, wherein synchronizing the time stamp to the time of receipt further comprises synchronizing the time stamp based, at least in part, on an exchange of the FTM request message and an initial FTM message transmitted in response to the FTM request message.

4. The method of claim 1, and further comprising transmitting the FTM request message from the first wireless transceiver device.

5. The method of claim 1, wherein the FTM request message is transmitted by a wireless transceiver device other than the first wireless transceiver device.

6. The method of claim 1, and further comprising:

receiving a block acknowledgment request message from the second wireless transceiver device; and

transmitting a block acknowledgment message to the second wireless transceiver device containing one or more parameters determined based, at least in part, on the time of receipt of the previously transmitted FTM message.

7. The method of claim 6, wherein the block acknowledgment message further comprises the computed time of flight.

8. The method of claim 6, and further comprising synchronizing the time stamp to the time of receipt of the previously transmitted FTM message based, at least in part, on a first clock signal maintained at the first wireless transceiver device synchronized to a second clock signal maintained at the second wireless transceiver device, and wherein the block acknowledgment message further comprises the time stamp.

9. The method of claim 1, and further comprising:

receiving a block acknowledgment request message from the second wireless transceiver device; and

transmitting a block acknowledgment message in response to receipt of the block acknowledgment request message, the block acknowledgment message comprising parameters indicative of the time of flight.

10. The method of claim 9, wherein the block acknowledgment message further comprises an estimated short interframe space (SIFS), the method further comprising receiving a report message from the second wireless transceiver device comprising a round trip time computed based, at least in part, on the estimated SIFS.

11. At a first wireless transceiver device, a method comprising:

receiving a fine timing measurement (FTM) request message from a second wireless transceiver device; and

transmitting a plurality of FTM messages, at least one of the plurality of FTM messages comprising a time stamp indicating a transmission time of a previously transmitted FTM message.

12. The method of claim 11, and further comprising transmitting a block acknowledgment request message, the block acknowledgment request message comprising transmission times of the plurality of FTM messages.

13. The method of claim 11, and further comprising transmitting a block acknowledgment request message, the block acknowledgment request message comprising differences in transmission times of consecutive of FTM messages transmitted from the first wireless transceiver device.

14. The method of claim 11, and further comprising:

transmitting a block acknowledgment request message; and

receiving a block acknowledgment message transmitted in response to receipt of the block acknowledgment request message.

15. The method of claim 14, wherein the block acknowledgment message is transmitted by the second wireless transceiver device.

16. The method of claim 14, wherein the block acknowledgment message is transmitted by a third wireless transceiver device other than the second wireless transceiver device.

17. The method of claim 14, wherein the block acknowledgment message comprises one or more parameters determined based, at least in part, on times of receipt of the plurality of FTM messages.

18. The method of claim 11, and further comprising:

transmitting a block acknowledgment request message to the second wireless transceiver device containing one or more parameters determined based, at least in part, on a time of receipt of the FTM request message; and

receiving a block acknowledgment message from the second wireless transceiver device.

19. A first wireless transceiver device, comprising:

a transceiver to transmit message to and receive messages from a wireless communication network; and

one or more processors to configured to;

obtain a plurality of fine timing measurement (FTM) messages at the transceiver from a second wireless transceiver device, the plurality of FTM messages being transmitted by the second wireless transceiver device in response to receipt, at the second wireless transceiver device, of an FTM request message, at least one of the plurality of FTM messages comprising a time stamp indicating a transmission time of a previously transmitted FTM message; and

compute a time of flight based, at least in part, on the time stamp and a time of receipt of the previously transmitted FTM message.

20. The first wireless transceiver device of claim 19, wherein the one or more processors are further configured to:

synchronize the time stamp to the time of receipt based, at least in part, on a first clock signal maintained at the first wireless transceiver device synchronized to a second clock signal maintained at the second wireless transceiver device; and

subtract the synchronized time stamp from the time of receipt.

21. The first wireless transceiver device of claim 20, wherein the one or more processors are further configured to synchronize the time stamp to the time of receipt based, at least in part, on an exchange of the FTM request message and an initial FTM message transmitted in response to the FTM request message.

22. The first wireless transceiver device of claim 19, wherein the FTM request message is transmitted by a wireless transceiver device other than the first wireless transceiver device.

23. The first wireless transceiver device of claim 19, wherein the one or more processors are further configured to:

obtain a block acknowledgment request message received at the transceiver and transmitted from the second wireless transceiver device; and

initiate transmission of a block acknowledgment message through the transceiver to the second wireless transceiver device containing one or more parameters determined based, at least in part, on the time of receipt.

24. The first wireless transceiver device of claim 23, wherein the block acknowledgment message further comprises the computed time of flight.

25. A first wireless transceiver device comprising:

a transceiver; and

one or more processors configured to;

obtain a fine timing measurement (FTM) request message received at the transceiver and transmitted from a second wireless transceiver device; and

initiate transmission of a plurality of FTM messages through the transceiver, at least one of the plurality of FTM messages comprising a time stamp indicating a transmission time of a previously received FTM message, in response to the FTM request message.

26. The first wireless transceiver device of claim 25, wherein the one or more processors are further configured to:

initiate transmission of a block acknowledgment request message through the transceiver, the block acknowledgment request message comprising transmission times of the plurality of FTM messages.

27. The first wireless transceiver device of claim 25, wherein the one or more processors are further configured to:

initiate transmission of a block acknowledgment request message through the transceiver; and

obtain a block acknowledgment message received at the transceiver and transmitted in response to receipt of the block acknowledgment request message.

28. The first wireless transceiver device of claim 27, wherein the block acknowledgment message is transmitted by the second wireless transceiver device.

29. The first wireless transceiver device of claim 27, wherein the block acknowledgment message is transmitted by a third wireless transceiver device other than the second wireless transceiver device.

30. The first wireless transceiver device of claim 27, wherein the block acknowledgment message comprises one or more parameters determined based, at least in part, on times of receipt of the plurality of FTM messages.