Proximity Detection

• US 20160165470A1
• Filed: 02/17/2016
• Published: 06/09/2016
• Est. Priority Date: 01/28/2014
• Status: Active Grant

• Current Assignee: Imagination Technologies Limited (Imagination Technologies Group Ltd.)
• Original Assignee: Imagination Technologies Limited (Imagination Technologies Group Ltd.)
• Inventors: Knowles, Ian
• Granted Patent: US 10,251,077 B2
• Time in Patent Office: Days
• CPC Class Codes: H04H 20/12 Arrangements for observation, testing or troubleshooting
• CPC Class Codes: H04H 20/71 Wireless systems
• CPC Class Codes: H04H 60/51 of receiving stations
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 40/16 based on interference
• 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

A method of estimating the proximity of a first device to a second device in a network causes the first device to perform a first measurement in a first period during which a control message broadcasted over the network instructs devices in the network to not transmit during the first period, wherein the second device disregards the control message and transmits a first signal during the first period which is measured by the first device during the first period, and forms a measure of the proximity of the first device to the second device in dependence on a strength of the first signal.

Claims

1. A method of estimating the proximity of a first device to a second device, the first and second devices capable of communicating according to a wireless communications protocol, the method comprising:

at the first device, performing a channel quality measurement during a first period of time;

at the first device, receiving a signal from the second device during at least a portion of the first period of time; and

forming a measure of the proximity of the first device to the second device in dependence on a strength of the signal received at the first device.

2. A method as claimed in claim 1, wherein the power of the received signal is modulated in a predefined pattern.

3. A method as claimed in claim 2, wherein said forming step comprises analysing a histogram so as to detect a representation of the predefined pattern, wherein the histogram indicates received power at the first device.

4. A method as claimed in claim 3, wherein the wireless communications protocol is an IEEE 802.11 protocol and the histogram is a received power indicator (RPI) histogram defined by the IEEE 802.11 protocol.

5. A method as claimed in claim 1, wherein the channel quality measurement is, in accordance with the wireless communications protocol, for detecting interference.

6. A method as claimed in claim 1, wherein the wireless communications protocol is an IEEE 802.11 protocol and the channel quality measurement is a measurement defined by the IEEE 802.11 protocol.

7. A method as claimed in claim 1, further comprising the step of receiving a control message which, according to the wireless communications protocol, instructs the first device to perform the channel quality measurement during the first period of time.

8. A method as claimed in claim 1, further comprising the step of, at the first device, performing another channel quality measurement during another period of time, wherein said forming step is additionally dependent on said another channel quality measurement.

9. A method as claimed in claim 1, further comprising the steps of:

at the second device, receiving an instruction to not transmit during the first period of time to enable the channel quality measurement to be performed by the first device during the first period of time; and

at the second device, disregarding said instruction and transmitting the signal during the portion of the first period of time.

10. A device for estimating the proximity of the device to a second device, the device and second device being capable of communicating according to a wireless communications protocol, the device comprising:

a controller configured to cause the device to perform a channel quality measurement during a first period of time;

a transceiver configured to receive a signal from the second device during at least a portion of the first period of time; and

a proximity estimator configured to form a measure of the proximity of the device to the second device in dependence on a strength of the signal received at the first device.

11. A device as claimed in claim 10, wherein the power of the received signal is modulated in a predefined pattern.

12. A device as claimed in claim 11, wherein the proximity estimator is configured to analyse a histogram so as to detect a representation of the predefined pattern, wherein the histogram indicates received power at the first device.

13. A device as claimed in claim 12, wherein the wireless communications protocol is an IEEE 802.11 protocol and the histogram is a received power indicator (RPI) histogram defined by the IEEE 802.11 protocol.

14. A device as claimed in claim 10, wherein the channel quality measurement is, in accordance with the wireless communications protocol, for detecting interference.

15. A device as claimed in claim 10, wherein the wireless communications protocol is an IEEE 802.11 protocol and the channel quality measurement is a measurement defined by the IEEE 802.11 protocol.

16. A device as claimed in claim 10, wherein the transceiver is configured to receive a control message which, according to the wireless communications protocol, instructs the device to perform the channel quality measurement during the first period of time.

17. A device as claimed in claim 10, wherein the controller is configured to cause the device to perform another channel quality measurement during another period of time, wherein the proximity estimator is configured to form the measure of the proximity in dependence on said another channel quality measurement and the strength of the signal received at the device.

18. A device capable of communicating with a second device according to a wireless communications protocol, the device comprising:

a transceiver; and

a controller configured to;

receive an instruction to not transmit during a first period of time to enable a channel quality measurement to be performed by the second device during the first period of time, and

disregard said instruction and cause the transceiver to transmit a signal during at least a portion of the first period of time.

19. A device as claimed in claim 18, wherein the transceiver is configured to modulate the transmission power of the signal according to a predefined pattern.

20. A device as claimed in claim 18, wherein the wireless communications protocol is an IEEE 802.11 protocol and the channel quality measurement is a measurement defined by the IEEE 802.11 protocol.