Device-free activity identification using fine-grained WiFi signatures

Patent metadata

Field	Value
Publication number	US-10104195-B2
Application number	US-201615074305-A
Country	US
Kind code	B2
Filing date	Mar 18, 2016
Priority date	Mar 20, 2015
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

A system includes a device that is disposed within an environment and is adapted to communicate over a radio frequency communication link. The system also includes a wireless access point disposed within the environment, including a wireless transceiver in communication with the device over a radio frequency communication link using a plurality of channels, and recording a channel state information data set for the radio frequency communication link. The system also includes a monitoring device including a memory storing a plurality of activity profiles, each of which includes an activity and a channel state information profile corresponding to the activity, and a processor receiving, from the wireless access point, the channel state information data set and determining, based on a comparison of the channel state information data set to the channel state information profile of each of the plurality of activity profiles, the activity of the person in the environment.

First claim

What is claimed is:

1. A system for identifying an activity of a person in an environment, comprising:
a communication device disposed within the environment and adapted to communicate over a radio frequency communication link;
a wireless access point disposed within the environment, said wireless access point including a wireless transceiver in communication with at least said communication device over a corresponding one of at least one radio frequency communication link, each of said at least one radio frequency communication link using a plurality of channels, said wireless access point being configured to record a channel state information data set, said channel state information data set being recorded for said one of said at least one radio frequency communication link at a corresponding time; and
a monitoring device including a memory storing a plurality of activity profiles, each of said activity profiles including an activity and at least one channel state information profile corresponding to said activity, and a processor receiving, from said wireless access point, said channel state information data set and determining, based on a comparison of said channel state information data set to each of said at least one channel state information profile of each of said plurality of activity profiles, the activity of the person in the environment at said time corresponding to said channel state information data set,
wherein said monitoring device determines the activity by classifying the activity as one of a walking activity and an in-place activity; if the activity is classified as a walking activity, identifying the walking activity; and, if the activity is classified as an in-place activity, identifying the in-place activity; and
wherein said monitoring device classifies the activity as one of a walking activity and an in-place activity by determining a moving variance based on said channel state information data set and a further channel state information data set and comparing said moving variance to a threshold.

2. The system of claim 1 , wherein said monitoring device classifies the activity as a walking activity if said moving variance is greater than said threshold.

3. The system of claim 1 , wherein said wireless access point is a WiFi access point.

4. The system of claim 3 , wherein said WiFi access point is an 802.11n access point.

5. A system for identifying an activity of a person in an environment, comprising:
a communication device disposed within the environment and adapted to communicate over a radio frequency communication link;
a wireless access point disposed within the environment, said wireless access point including a wireless transceiver in communication with at least said communication device over a corresponding one of at least one radio frequency communication link, each of said at least one radio frequency communication link using a plurality of channels, said wireless access point being configured to record a channel state information data set, said channel state information data set being recorded for said one of said at least one radio frequency communication link at a corresponding time; and
a monitoring device including a memory storing a plurality of activity profiles, each of said activity profiles including an activity and at least one channel state information profile corresponding to said activity, and a processor receiving, from said wireless access point, said channel state information data set and determining, based on a comparison of said channel state information data set to each of said at least one channel state information profile of each of said plurality of activity profiles, the activity of the person in the environment at said time corresponding to said channel state information data set,
wherein said monitoring device determines the activity by classifying the activity as one of a walking activity and an in-place activity; if the activity is classified as a walking activity, identifying the walking activity; and, if the activity is classified as an in-place activity, identifying the in-place activity; and
wherein said monitoring device identifies the in-place activity by comparing a histogram of said channel state information data set to a histogram of each of said at least one channel state information profile of each of said plurality of activity profiles.

6. The system of claim 5 , wherein said monitoring device compares said histogram of said channel state information data set to said histogram of each of said at least one channel state information profile of each of said plurality of activity profiles using an earth mover's distance comparison.

7. A system for identifying an activity of a person in an environment, comprising:
a communication device disposed within the environment and adapted to communicate over a radio frequency communication link;
a wireless access point disposed within the environment, said wireless access point including a wireless transceiver in communication with at least said communication device over a corresponding one of at least one radio frequency communication link, each of said at least one radio frequency communication link using a plurality of channels, said wireless access point being configured to record a channel state information data set, said channel state information data set being recorded for said one of said at least one radio frequency communication link at a corresponding time; and
a monitoring device including a memory storing a plurality of activity profiles, each of said activity profiles including an activity and at least one channel state information profile corresponding to said activity, and a processor receiving, from said wireless access point, said channel state information data set and determining, based on a comparison of said channel state information data set to each of said at least one channel state information profile of each of said plurality of activity profiles, the activity of the person in the environment at said time corresponding to said channel state information data set,
wherein said monitoring device determines the activity by classifying the activity as one of a walking activity and an in-place activity; if the activity is classified as a walking activity, identifying the walking activity; and, if the activity is classified as an in-place activity, identifying the in-place activity; and
wherein said monitoring device identifies the walking activity by comparing a time series of said channel state information data set to a time series of each of said at least one channel state information profile of each of said activity profiles.

8. The system of claim 7 , wherein said monitoring device compares said time series of said channel state information data set to a time series of each of said at least one channel state information profile of each of said activity profiles using dynamic time warping.

9. A system for identifying an activity of a person in an environment, comprising:
a communication device disposed within the environment and adapted to communicate over a radio frequency communication link;
a wireless access point disposed within the environment, said wireless access point including a wireless transceiver in communication with at least said communication device over a corresponding one of at least one radio frequency communication link, each of said at least one radio frequency communication link using a plurality of channels, said wireless access point being configured to record a channel state information data set, said channel state information data set being recorded for said one of said at least one radio frequency communication link at a corresponding time; and
a monitoring device including a

Assignees

• Stevens Institute Of Technology
• Univ Rutgers

Inventors

• Chen Yingying
• Yang Jie
• Wang Yan
• Liu Jian
• Gruteser Marco

Classifications

• H04W4/33

  for indoor environments, e.g. buildings · CPC title

• H04W4/029

  Location-based management or tracking services · CPC title

• H04W4/30

  Services specially adapted for particular environments, situations or purposes · CPC title

• H04W88/08

  Access point devices · CPC title

• H04W84/12

  WLAN [Wireless Local Area Networks] · CPC title