Methods and systems for synchronizing devices

Patent metadata

Field	Value
Publication number	US-2016262122-A1
Application number	US-201514850459-A
Country	US
Kind code	A1
Filing date	Sep 10, 2015
Priority date	Mar 3, 2015
Publication date	Sep 8, 2016
Grant date	—

Abstract

Disclosed are methods and systems for synchronizing clocks maintained at different devices in a wireless communication network. A first wireless transceiver device may receive one or more messages from a second wireless transceiver device with parameters indicative of a first clock state. The first wireless transceiver device may then synchronize a second clock state maintained at the first wireless device based, at least in part, on the one or more parameters indicative of the first clock state.

First claim

What is claimed is:

1 . A method, at a first wireless station (STA), comprising:
receiving one or more first messages from a second STA comprising one or more parameters characterizing a state of a grand master clock; and synchronizing a first clock maintained at the first STA with a second clock maintained at the second STA based, at least in part, on the one or more parameters characterizing the state of the grand master clock and an expected difference between a first drift of the first clock and a second drift of the second clock.

2 . The method of claim 1 , and further comprising computing the expected difference based, at least in part, on arrival times of second messages at the first STA transmitted in bursts from the second STA.

3 . The method of claim 2 , and further comprising computing the expected difference based, at least in part, on a Neighbor Rate Ratio.

4 . The method of claim 2 , wherein the second messages comprise fine timing measurement (FTM) messages.

5 . The method of claim 1 , and further comprising measuring a time of flight of a third message transmitted from the second STA to the first STA based, at least in part, on the synchronized first clock.

6 . The method of claim 1 , wherein the first STA comprises a first wireless audio speaker device and the second STA comprises a second wireless audio speaker device, and wherein the method further comprises:
transmitting one more second messages to a third wireless audio speaker device, the one or more third messages comprising one or more parameters based, at least in part, on the synchronized first clock.

7 . The method of claim 1 , wherein the one or more first messages are transmitted by the second STA in response to at least one fine timing measurement (FTM) request message, the FTM request message comprising one or more fields indicating an ability or preference for FTM messages or timing measurement messages as the one or more first messages.

8 . The method of claim 1 , wherein the first STA comprises an initiating STA, and the second STA comprises a responding STA.

9 . A first wireless station (STA), comprising:
a wireless transceiver to transmit messages to and receive messages from a wireless communication network; a first clock; and one or more processors configured to: obtain one or more first messages received at the wireless transceiver from a second STA comprising one or more parameters characterizing a state of a grand master clock; and synchronize a state of the first clock with a state of a second clock maintained at the second STA based, at least in part, on the one or more parameters characterizing the state of the grand master clock and an expected difference between a first drift of the first clock and a second drift of the second clock.

10 . The first STA of claim 9 , wherein the one or more processors are further configured to compute the expected difference based, at least in part, on arrival times of second messages at the first STA transmitted in bursts from the second STA.

11 . The first STA of claim 10 , wherein the one or more processors are further configured to compute the expected difference based, at least in part, on a Neighbor Rate Ratio.

12 . The first STA of claim 10 , wherein the second messages comprise fine timing measurement (FTM) messages.

13 . The first STA of claim 9 , wherein the one or more processors are further configured to measure a time of flight of a third message transmitted from the second STA to the first STA based, at least in part, on the synchronized first clock.

14 . The first STA of claim 9 , wherein the first STA comprises a first wireless audio speaker device and the second STA comprises a second wireless audio speaker device, and wherein the one or more processors are further configured to:
initiate transmission of one more second messages to a third wireless audio speaker device, the one or more third messages comprising one or more parameters based, at least in part, on the synchronized first clock.

15 . The first STA of claim 9 , wherein the one or more first messages are transmitted by the second STA in response to at least one fine timing measurement (FTM) request message, the FTM request message comprising one or more fields indicating an ability or preference for FTM messages or timing measurement messages as the one or more first messages.

16 . The first STA of claim 9 , wherein the first STA comprises an initiating STA, and the second STA comprises a responding STA.

17 . A non-transitory storage medium comprising machine-readable instructions stored thereon which are executable by one or more processors of a first wireless station (STA) to:
obtain one or more first messages received from a second STA comprising one or more parameters characterizing a state of a grand master clock; and synchronize a state of a first clock maintained at the first STA with a state of a second clock maintained at the second STA based, at least in part, on the one or more parameters characterizing the state of the grand master clock and an expected difference between a first drift of the first clock and a second drift of the second clock.

18 . The non-transitory storage medium of claim 17 , wherein the instructions are further executable by the one or more processors to compute the expected difference based, at least in part, on arrival times of second messages at the first STA transmitted in bursts from the second STA.

19 . The non-transitory storage medium of claim 18 , wherein the instructions are further executable by the one or more processors to compute the expected difference based, at least in part, on a Neighbor Rate Ratio.

20 . The non-transitory storage medium of claim 18 , wherein the second messages comprise fine timing measurement (FTM) messages.

21 . The non-transitory storage medium claim 17 , wherein the instructions are further executable by the one or more processors to measure a time of flight of a third message transmitted from the second STA to the first STA based, at least in part, on the synchronized first clock.

22 . The non-transitory storage medium of claim 17 , wherein the first STA comprises a first wireless audio speaker device and the second STA comprises a second wireless audio speaker device, and wherein the instructions are further executable by the one or more processors to:
initiate transmission of one more second messages to a third wireless audio speaker device, the one or more third messages comprising one or more parameters based, at least in part, on the synchronized first clock.

23 . The non-transitory storage medium of claim 17 , wherein the one or more first messages are transmitted by the second STA in response to at least one fine timing measurement (FTM) request message, the FTM request message comprising one or more fields indicating an ability or preference for FTM messages or timing measurement messages as the one or more first messages.

24 . The non-transitory storage medium of claim 17 , wherein the first STA comprises an initiating STA, and the second STA comprises a responding STA.

25 . A first wireless station (STA), comprising:
means for receiving one or more first messages from a second STA comprising one or more parameters characterizing a state of a grand master clock; and means for synchronizing a first clock maintained at the first STA with a second clock maintained at the second ST

Assignees

• Qualcomm Inc

Inventors

• Aldana Carlos Horacio

Classifications

• H04W56/0015 Primary

  one node acting as a reference for the others · CPC title

• H04W72/0446

  Resources in time domain, e.g. slots or frames · CPC title

• H04W24/10

  Scheduling measurement reports {; Arrangements for measurement reports} · CPC title

• H04W56/0035

  detecting errors in frequency or phase · CPC title

• H04J3/0667

  Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays (arrangements for monitoring round trip delays in packet switching networks H04L43/0864) · CPC title