Tagless radio frequency based self correcting distributed real time location system

• US 9,655,074 B2
• Filed: 09/01/2011
• Issued: 05/16/2017
• Est. Priority Date: 09/01/2010
• Status: Active Grant

• Current Assignee: Movvo, S.A.
• Original Assignee: Movvo, S.A.
• Inventors: Di Cera Colazingari, Roberto Ugo
• Primary Examiner(s): HAMMONDS, MARCUS C
• Application Number:
  US13/820,433
• Publication Number:
  US 20130231131A1
• Time in Patent Office: 2,084 Days
• Field of Search: 4554561-457
• CPC Class Codes: G01S 5/02 using radio waves using satellite radio beacon systems for determining position G01S19/00
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Services based on radio frequencies like GPS, RFID, GSM, CDMA, Wi-Fi or Bluetooth triangulation allows us to know, with some level of confidence, the position of a mobile device. However, those methods rely on special software and/or hardware. They also fail inside buildings since they cannot provide fine granulated values with a high level of accuracy. Each radio frequency device (mobile or not) emits a signal with a given strength and identification (Mac address or similar) to the air. The signal is captured by our nodes (at least 2 of the nodes), that measures the strength of the signal and therefore calculate the distance estimation. Since the signal is affected by electromagnetic noise, number of people in the building, or even temperature, the suggested system self corrects the values by knowing the distance between the nodes and measuring the signal strength. This gives to the system a very low error margin of about 1%. Some applications rely on real time tracking solutions, that traditional tracking systems cannot provide or need to provide tags to follow devices. The system here presented is distributed to be able to process the signal in real time (connected via a high speed network), with low latency and also stores the location estimation, device identification and time collected for analytics and reporting.

Claims

1. A system for determining position of devices in a network in real time, the system comprising:

one or more detecting nodes to (i) detect signal strength of radio frequency signals emitted by one or more devices, (ii) retrieve a unique identifier from each of the one or more devices, and (iii) communicate calibration packets to other detecting nodes at predetermined periodic intervals, the one or more detecting nodes storing together the signal strength, unique identifier and calibration packets as location determining data;

a local server connected to each of the one or more detecting nodes, to (a) receive the location determining data including the calibration packets from said each of the one or more detecting nodes and generate a timestamp for the received location determining data including the calibration packets, and

(b) determine, for each of the one or more devices, location information by calculating a distance of each of the one or more devices relative to said each of the one or more detecting nodes based on the received location determining data including the calibration packets; and

a main server to perform analysis on the location information and the data received by the local server from each of the one or more devices.

2. The system according to claim 1, further comprising:

another local server that is connected to the main server; and

one or more additional detecting nodes,

wherein said another local server and the one or more additional detecting nodes are connected in a network that is separated from the network including the one or more device and the local server.

3. The system according to claim 1, wherein the calibration packets are communicated as Wi-Fi packets at predetermined periodic intervals.

4. The system according to claim 1, wherein the retrieved unique identifier corresponding to each of the one or more devices is a MAC address.

5. The system according to claim 2, wherein the calibration packets are communicated as Wi-Fi packets at predetermined periodic intervals.

6. The system according to claim 2, wherein the retrieved unique identifier corresponding to each of the one or more devices is a MAC address.

7. The system according to claim 3, wherein the retrieved unique identifier corresponding to each of the one or more devices is a MAC address.