DEVICES, METHODS, AND APPARATUSES FOR COMPUTING ROUND-TRIP TIME OF A MESSAGE

• US 20140253386A1
• Filed: 03/11/2013
• Published: 09/11/2014
• Est. Priority Date: 03/11/2013
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gao, Weihua, Hu, Yuhua, Zhang, Gengsheng, Venkatraman, Sai Pradeep, Sun, Ming
• Application Number:
  US13/794,559
• Publication Number:
  US 20140253386A1
• Time in Patent Office: Days
• US Class Current: 342/387
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/876 Combination of several spaced transponders or reflectors of known location for determining the position of a receiver G01S13/874 takes precedence
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence

Abstract

Methods, apparatuses, and/or articles of manufacture are disclosed, which may be employed in a mobile device communicating with a transponder via a near field communications channel. In one example, round trip time of a message may be computed to estimate processing latency contributed by processes occurring within the mobile device and/or the transponder.

Claims

1. A method, comprising, at a mobile device comprising a transceiver:

placing a first antenna into proximity with a second antenna coupled to a transponder;

transmitting, through said first antenna, coupled to said transceiver, a first message comprising a first time-stamp;

providing a second time-stamp in response to receipt of a second message transmitted by said transponder in response to said first message, said second message comprising said first time-stamp; and

estimating a processing latency based, at least in part, on comparing said first and second time-stamps.

2. The method of claim 1, wherein said estimating further comprises subtracting, by said transceiver, said first time-stamp from said second time-stamp.

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

relocating said transceiver relative to said transponder;

transmitting a third message comprising a third time-stamp from said relocated transceiver to said transponder; and

said transponder transmitting a fourth message, said fourth message comprising said third time-stamp, said transmitting being at least partially in response to receipt of said third message; and

estimating a round-trip time (RTT) of a message between said relocated transceiver and said transponder based, at least in part, on a difference between said third time-stamp and a fourth time-stamp associated with receipt of said fourth message, less said estimated processing latency.

4. The method of claim 3, and further comprising:

computing an estimated range from said relocated transceiver to said transponder based, at least in part, on said estimated RTT.

5. The method of claim 3, and further comprising detecting, responsive to said relocation of said transceiver, that a near field communications channel is not present.

6. The method of claim 3, and further comprising:

estimating a location of said relocated transceiver based, at least in part, on an association of said estimated RTT with an RTT signature value from a radio heat map.

7. The method of claim 6, wherein said estimating said location of said relocated transceiver comprises:

comparing said estimated RTT with a plurality of RTT signature values of said radio heat map; and

determining said location estimate based, at least in part, on a correlation between said estimated RTT and at least one of said plurality of RTT signature values of said radio heat map.

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

initiating said transmitting by said transceiver coupled to said first antenna at least partially in response to detection of a near field communications channel from said transponder.

9. The method of claim 8, wherein said detection of said near field communications channel comprises detection of a time-varying magnetic field having a strength above a threshold value.

10. The method of claim 1, herein said proximity between said first antenna and said second antenna comprises a distance of less than approximately 30.0 cm.

11. A mobile device comprising:

a transceiver; and

one or more processors to;

detect presence of a near field communications channel at said transceiver;

generate a first time-stamp for transmission using a field communications channel;

associate a time-stamp with a message received using said far field communications channel, said received message comprising said first time-stamp; and

compare said first time-stamp with said time-stamp associated with said received message.

12. The mobile device of claim 11, wherein said one or more processors additionally estimates a processing latency of a transponder communicating through said far field communications channel based, at least in part, on said comparing.

13. The mobile device of claim 12, wherein said one or more processors additionally:

initiate transmission, based at least in part on relocation of said transceiver, a message comprising a second time-stamp from said transceiver to said transponder; and

process a message from said transponder, said transponder transmitting a message comprising said second time-stamp; and

compute an estimate of round-trip time (RTT) of a message from said relocated transceiver and said transponder based, at least in part, on a difference between said second time-stamp and a time-stamp associated with said processed message from said transponder.

14. The mobile device of claim 13, wherein said one or more processors additionally detects an absence of a near field communications signal responsive to said relocation of said transceiver.

15. The mobile device of claim 13, wherein said one or more processors additionally computes an estimated range from said relocated transceiver to said transponder based, at least in part, on said computed estimate of RTT.

16. The mobile device of claim 15, wherein said one or more processors additionally estimate a location of said relocated transceiver based, at least in part, on an association of said estimated RTT with an RTT signature value from a radio heat map.

17. The mobile device of claim 16, wherein said one or more processors additionally associate said RTT signature value from said radio heat map based, at least in part, on a media access control identification (MAC ID) address received from said transponder.

18. The mobile device of claim 11, further comprising at least one inductive loop to receive and transmit near field communication signals.

19. The mobile device of claim 11, wherein said transceiver comprises a wireless access point.

20. The mobile device of claim 13, wherein said transceiver comprises a mobile communications device.

21. An article comprising:

a storage medium comprising machine-readable instructions stored thereon which are executable by a special purpose computing apparatus to;

initiate transmission, in response to detection of a near field communications channel, a first message comprising a first time-stamp;

associate a second time-stamp with a second message, said second message received through a far field communications channel; and

compare said second time-stamp to said first time-stamp.

22. The article of claim 21, wherein said storage medium additionally comprises machine-readable instructions stored thereon which are executable by a special-purpose computing apparatus to:

extract said first time-stamp from said message received through said far field communications channel.

23. The article of claim 21, wherein said storage medium additionally comprises machine-readable instructions stored thereon which are executable by a special-purpose computing apparatus to:

estimate a processing latency of a transponder communicating through said far field communications channel based, at least in part, on said comparing.

24. The article of claim 23, wherein said estimate of said processing latency of said transponder comprises at least one of the group consisting of:

latency for downconverting a modulated signal,

latency for demodulating said modulated signal,

latency for processing a request extracted from one or more media access control frames,

latency for forming a response using one or more media access control frames,

latency for modulating a signal comprising said response,

latency for upconverting said signal comprising said response,

or any combination thereof.

25. The article of claim 23, wherein said storage medium additionally comprises machine-readable instructions stored thereon which are executable by a special-purpose computing apparatus to:

initiate transmission, from a transceiver, of a third message comprising a third time-stamp if said transceiver has been relocated;

extract, from a message received from a transponder, said third time-stamp;

associate a fourth time-stamp with said message received from said transponder; and

compute an estimate of a round-trip time (RTT) of a message between said relocated transceiver and said transponder based, at least in part, on a difference between said third time-stamp and said fourth time-stamp, less said estimate of said processing latency.

26. The article of claim 25, wherein said storage medium additionally comprises machine-readable instructions stored thereon which are executable by a special-purpose computing apparatus to:

initiate transmission of said third message through said far field communications channel if said transceiver has been relocated.

27. The article of claim 25, wherein said storage medium additionally comprises machine-readable instructions stored thereon which are executable by a special-purpose computing apparatus to:

estimate a location of said relocated transceiver based, at least in part, on an association of said computed estimate of RTT with an RTT signature value from a radio heat map.

28. The article of claim 27, wherein said storage medium additionally comprises machine-readable instructions stored thereon which are executable by a special-purpose computing apparatus to:

associate said RTT signature value from said radio heat map based, at least in part, on a MAC ID address received from said transponder.

29. A mobile device comprising:

means for determining that a transceiver is proximate with a transponder via a near field communications channel;

means for transmitting a first time-stamped message to said transponder;

means for associating a second time-stamp with a second message, said second message transmitted by said transponder in response to said transponder receiving said first time-stamped message, said second message comprising said first time-stamp; and

means for determining processing latency of a transponder using said first and said second time-stamps.

30. The mobile device of claim 29, wherein said means for determining that a transceiver is proximate with a transponder comprises means for detecting presence of a time-varying magnetic field of a strength above a threshold level.

31. The mobile device of claim 29, wherein said means for transmitting comprises a far field antenna.

32. The mobile device of claim 29, wherein said means for determining that a transceiver is proximate with a transponder comprises an inductive loop.

33. The mobile device of claim 29, wherein said means for determining said processing latency comprises one or more processors to compare, at said mobile device, said first and said second time-stamps.

34. The mobile device of claim 29, further comprising means for determining round-trip time from said transceiver to said transponder responsive to relocating said transceiver.

35. The mobile device of claim 34, wherein said means for determining round-trip time from said transceiver to said transponder further comprises:

means for transmitting a third time-stamped message to said transponder via a far field antenna;

means for receiving a fourth message, said fourth message comprising said third time-stamp; and

means for determining a round-trip time of said third time-stamped message to said transponder, less said processing latency.

36. The mobile device of claim 35, further comprising means for detecting that a near field communications channel is absent.

37. The mobile device of claim 35 further comprising:

means for estimating a range from said mobile device to said transponder.

38. The mobile device of claim 37, wherein said means for estimating said range comprises means for associating an estimated RTT with an RTT signature value from a radio heat map.

39. The mobile device of claim 38, wherein said means for associating said estimated RTT with an RTT signature value comprises determining a MAC ID address received from said transponder.