Passive device monitoring using radio frequency signals

• US 9,245,433 B1
• Filed: 12/20/2013
• Issued: 01/26/2016
• Est. Priority Date: 12/20/2013
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Butler, David George, Mincher, Richard William
• Primary Examiner(s): Mullen, Thomas
• Application Number:
  US14/136,488
• Time in Patent Office: 767 Days
• Field of Search: 340/541, 340/539.13, 340/573.4, 340/5.2, 340/5.21, 340/5.27, 340/5.3, 340/5.8, 455/456.1, 455/456.6
• US Class Current: 1/1
• CPC Class Codes: G08B 13/00 Burglar, theft or intruder alarms
• CPC Class Codes: H04L 61/4547 for personal communications, i.e. using a personal identifier
• CPC Class Codes: H04W 12/12 Detection or prevention of fraud
• CPC Class Codes: H04W 12/79 Radio fingerprint
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/029 Location-based management or tracking services
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]

Abstract

A rule-based machine learning system monitors frequency bands to detect transmissions from nearby active transmitters, such as those associated with wireless mobile devices. The system logs unique identifiers (UID) embedded in detected transmissions, recognizes patterns of UID detection over time, and selectively takes action when UIDs are detected and when they are expected but absent.

Claims

1. A method of providing home security monitoring, comprising:

passively monitoring to detect radio frequency (RF) signals using a wireless protocol;

detecting a first RF signal;

extracting information comprising a first unique identifier (UID) from the detected first RF signal, wherein the first UID uniquely identifies a first device emitting the first RF signal, the UID comprising information that is hardcoded into a chip on the first device and always used for communications as a condition of the wireless protocol associated with the RF signals;

estimating a first location of an origin of the first RF signal;

determining that the first UID is unknown;

identifying a first rule of a plurality of rules, the first rule including criteria that if an unknown UID is detected within a first range of time, the first location is within a second range of locations, and a home resident is absent, a first message is sent to the home resident that an unidentified individual is present; and

in accordance with the first rule, sending the first message after determining that the time of detection of the first UID is within the first range of time, the first location is within the second range of locations, and a second UID associated with a second device of the home resident is absent.

2. The method of claim 1, further comprising:

detecting a second RF signal;

extracting information comprising a third unique identifier (UID) from the detected second RF signal, wherein the third UID uniquely identifies a third device emitting the second RF signal;

making a record of detections of the third UID;

determining that the third UID is unknown;

applying pattern recognition to the record of detections of the third UID to determine a correlation of occurrences of the third UID with detection of at least one device associated with the home resident;

generating an inference that the unknown third UID is associated with a guest of the home resident based on the correlation of occurrences;

identifying a second rule of the plurality of rules, the second rule including criteria that if a guest of the home resident is detected and the home resident is absent, a second message is sent to the home resident that the guest is present; and

in accordance with the second rule, sending the second message after determining that there is an inference that the unknown third UID is the guest of the home resident, and that the second UID associated with the second device of the home resident is absent.

3. The method of claim 1, further comprising:

estimating a second location of the origin of the first RF signal, wherein the second location is different than the first location;

identifying a second rule of the plurality of rules, the second rule including criteria that if an unknown UID is detected within a third range of locations and the home resident is absent, a second message is sent to the home resident that there is suspicious activity inside the home and an audible alarm is activated, wherein boundaries of the third range of locations are inside those of the second range of locations; and

in accordance with the second rule, sending the second message and activating the audible alarm after determining that the second location is within the third range of locations, and the second UID associated with the second device of the home resident is absent.

4. The method of claim 1, further comprising:

after detecting the first RF signal, receiving a second location for the first UID of the first device from a second RF monitoring device, wherein the second RF monitoring device is associated with a neighbor of the home resident;

identifying a second rule of the plurality of rules, the second rule including criteria that if an unknown UID is detected in a neighborhood for over a threshold duration of time, a second message is sent to the home resident that an unidentified individual is loitering; and

in accordance with the second rule, sending the second message after determining that a difference in time between detection of the first UID at the first location and detection of the first UID at the second location exceeds the threshold duration of time.

5. A computing device comprising:

at least one antenna;

a radio frequency (RF) receiver connected to the at least one antenna;

at least one processor connected to the RF receiver;

a memory including instructions operable to be executed by the at least one processor to perform a set of actions, configuring the at least one processor to;

monitor the RF receiver to detect RF signals using a wireless protocol;

extract information comprising a first identifier from a first detected RF signal, wherein the first identifier identifies a transmitting device emitting the first detected RF signal;

determine whether the first identifier is associated with a known individual;

identify a first rule including criteria to perform a first action based on whether the first identifier is associated with a known individual; and

perform the first action in accordance with the first rule based at least in part on the first identifier being associated with an unknown individual.

6. The computing device of claim 5, wherein the at least one processor is further configured to:

make a first record of the first identifier associated with the unknown individual, together with a time of detection of the first detected RF signal.

7. The computing device of claim 6, wherein the instructions to extract the information comprising the first identifier from the first detected RF signal comprise instructions to extract information comprising a respective identifier from each of the detected RF signals, wherein each respective identifier identifies a transmitting device emitting a respective detected RF signal, and wherein the at least one processor is further configured to:

make a plurality of records over time, including the first record, where each record of the plurality of records includes the first identifier associated with the unknown individual and a respective time of detection of the respective detected RF signal from which information including the first identifier was extracted; and

apply pattern recognition to the plurality of records to recognize a pattern over time, wherein at least one criterion of the first rule is satisfied based on the pattern.

8. The computing device of claim 6, wherein the at least one processor is configured to estimate an origin location of the first detected RF signal, wherein:

the criteria of the first rule further comprise location criteria for unknown identifiers and time of detection criteria of an RF signal associated with an unknown identifier,

the estimated origin location and the time of detection of the first detected RF signal satisfy the location criteria and time of detection criteria of the first rule, and

the first action comprises at least one of generating a message, triggering an audible alarm, and turning on a light.

9. The computing device of claim 5, wherein the instructions to extract the information comprising the first identifier from the first detected RF signal comprise instructions to extract information comprising a respective identifier from each of the detected RF signals, wherein each respective identifier identifies a transmitting device emitting a respective detected RF signal, and wherein the at least one processor is further configured to:

check the detected RF signals for a presence of a second RF signal including a second identifier at a specific time; and

perform a second action in accordance with a second rule based on a failure to detect the presence of the second RF signal including the second identifier at the specific time, the second action comprising sending a message to a specified individual that an individual associated with the second identifier was absent at the specific time.

10. The computing device of claim 9, wherein the at least one processor is further configured to:

make a plurality of records over time, where each record includes the second identifier and a respective time of detection of each of the detected RF signals from which information including the second identifier was extracted; and

apply pattern recognition to recognize a pattern of the times of detection in the plurality of records, wherein the specific time that the at least one processor is configured to check the detected RF signals for the presence of the second RF signal including the second identifier is based on the pattern of the times of detection.

11. The computing device of claim 5, wherein the instructions to extract the information comprising the first identifier from the first detected RF signal comprise instructions to extract information comprising a respective identifier from each of the detected RF signals, wherein each respective identifier identifies a transmitting device emitting a respective detected RF signal, and wherein the at least one processor is further configured to:

make a record of identifiers in the information extracted from the detected RF signals, together with a time of detection of respective RF signals corresponding to each of the identifiers;

determine that a second identifier is associated with a known individual; and

omit the second identifier and corresponding time of detection from the record.

12. A non-transitory computer readable medium having stored thereon instructions to configure a computing device to:

monitor a radio frequency (RF) receiver to detect RF signals using a wireless protocol;

extract information comprising a first identifier from a first detected RF signal, wherein the first identifier identifies a transmitting device emitting the first detected RF signal;

determine whether the first identifier is associated with a known individual;

identify a first rule including criteria to perform a first action based on whether the first identifier is associated with a known individual; and

perform the first action in accordance with the first rule based at least in part on the first identifier being associated with an unknown individual.

13. The non-transitory computer readable medium according to claim 12, further configuring the computing device to:

make a first record of the first identifier associated with the unknown individual, together with a time of detection of the first detected RF signal.

14. The non-transitory computer readable medium according to claim 13, wherein the instructions to extract the information comprising the first identifier from the first detected RF signal comprise instructions to extract information comprising a respective identifier from each of the detected RF signals, wherein each respective identifier identifies a transmitting device emitting a respective detected RF signal,

the non-transitory computer readable medium further configuring the computing device to:

make a plurality of records over time, including the first record, where each record of the plurality of records includes the first identifier associated with the unknown individual and a respective time of detection of the respective detected RF signal from which information including the first identifier was extracted; and

apply pattern recognition to the plurality of records to recognize a pattern over time, wherein at least one criterion of the first rule is satisfied based on the pattern.

15. The non-transitory computer readable medium according to claim 12, wherein the computing device is to estimate an origin location of the first detected RF signal, wherein:

the criteria of the first rule further comprise location criteria for unknown identifiers and time of detection criteria of an RF signal associated with an unknown identifier,

the estimated origin location and the time of detection of the first detected RF signal satisfy the location criteria and time of detection criteria of the first rule, and

the first action comprises at least one of generating a message, triggering an audible alarm, and turning on a light.

16. The non-transitory computer readable medium according to claim 12, wherein the instructions to extract the information comprising the first identifier from the first detected RF signal comprise instructions to extract information comprising a respective identifier from each of the detected RF signals, wherein each respective identifier identifies a transmitting device emitting a respective detected RF signal,

the non-transitory computer readable medium further configuring the computing device to:

check the detected RF signals for a presence of a second RF signal including a second identifier at a specific time; and

perform a second action in accordance with a second rule based on a failure to detect the presence of the second RF signal including the second identifier at the specific time, the second action comprising sending a message to a specified individual that an individual associated with the second identifier was absent at the specific time.

17. The non-transitory computer readable medium according to claim 16, further configuring the computing device to:

make a plurality of records over time, where each record includes the second identifier and a respective time of detection of each of the detected RF signals from which information including the second identifier was extracted; and

apply pattern recognition to recognize a pattern of the times of detection in the plurality of records, wherein the specific time that the at least one processor is configured to check the detected RF signals for the presence of the second RF signal including the second identifier is based on the pattern of the times of detection.

18. The non-transitory computer readable medium according to claim 12, wherein the instructions to extract the information comprising the first identifier from the first detected RF signal comprise instructions to extract information comprising a respective identifier from each of the detected RF signals, wherein each respective identifier identifies a transmitting device emitting a respective detected RF signal,

the non-transitory computer readable medium further configuring the computing device to:

make a record of identifiers in the information extracted from the detected RF signals, together with a time of detection of respective RF signals corresponding to each of the identifiers;

determine that a second identifier is associated with a known individual; and

omit the second identifier and corresponding time of detection from the record.