Method and system for determining the altitude of a mobile wireless device

• US 7,991,405 B2
• Filed: 11/02/2009
• Issued: 08/02/2011
• Est. Priority Date: 07/30/2002
• Status: Expired due to Fees

• Current Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Inventors: Zhao, Wei
• Primary Examiner(s): DOAN, PHUOC HUU
• Application Number:
  US12/610,684
• Publication Number:
  US 20100049744A1
• Time in Patent Office: 638 Days
• Field of Search: 455/456.5, 342/457
• US Class Current: 455/456.1
• CPC Class Codes: H04B 1/3805 with built-in auxiliary receivers
• CPC Class Codes: H04W 4/33 for indoor environments, e.g. buildings
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• 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 64/006 with additional information processing, e.g. for direction or speed determination
• CPC Class Codes: H04W 76/50 for emergency connections

Abstract

A method and system for determining the three-dimensional location of a mobile wireless device. In one implementation, the device is a cellular telephone making a 911 call from one floor of a multi-story building. An embodiment of the method of the invention includes establishing a database that associates transmission metrics with altitudes of x-y coordinate locations having more than one altitude at which the mobile wireless device could be located, receiving a communication from the mobile wireless device, determining an x-y coordinate location of the mobile wireless device, measuring a transmission metric of the mobile wireless device, and consulting the database to determine the altitude from the x-y coordinate location and the measured transmission metric. The transmission metric could be, for example, the transmission time or angle of arrival of a wireless signal received from the mobile wireless device.

Claims

1. A method for constructing a database for locating a device in three dimensional space, the method comprising:

identifying, in three dimensional space, a plurality of locations comprising an X coordinate, a Y coordinate, and a respective plurality of Z coordinates, wherein each of the plurality of Z coordinates corresponds to a respective altitude having the X coordinate and the Y coordinate;

receiving, at a first reception site, a plurality of signals, each signal of the plurality of signals being indicative of a mobile device being positioned at a respective location of the plurality of locations;

determining a metric for each signal of the plurality of signals received at the first reception site; and

constructing the database comprising, for each of the plurality of locations, the X coordinate, the Y coordinate, a respective Z coordinate, and a respective metric.

2. The method of claim 1, wherein the database is further constructed to comprise a description of each of the plurality of locations.

3. The method of claim 1, wherein the metric comprises at least one of:

an angle of arrival of each signal;

or

a time period for each signal to travel from a respective one of the plurality of locations to the first reception site.

4. The method of claim 1, further comprising:

determining additional metrics for each signal of the plurality of signals; and

constructing the database respectively comprising the additional metrics.

5. The method of claim 4, wherein the additional metrics comprise at least one of:

an angle of arrival of each signal;

or

a time period for each signal to travel from a respective one of the plurality of locations to the first reception site.

6. The method of claim 1, further comprising:

receiving, at at least one additional reception site, the plurality of signals, each signal of the plurality of signals being indicative of a mobile device being positioned at a respective location of the plurality of locations;

determining a metric for each signal of the plurality of signals received at the at least one additional reception site; and

constructing the database further comprising a respective metric determined for a respective signal received at the at least one additional reception site.

7. The method of claim 6, wherein the metric comprises at least one of:

an angle of arrival of each signal;

or a time period for each signal to travel from a respective one of the plurality of locations to a respective reception site.

8. The method of claim 6, further comprising:

determining additional metrics for each signal of the plurality of signals received at each respective reception site; and

constructing the database respectively comprising the additional metrics.

9. The method of claim 8, wherein the additional metrics comprise at least one of:

an angle of arrival of each signal;

or

a time period for each signal to travel from a respective one of the plurality of locations to a respective reception site.

10. A processor having computer-executable instructions stored thereon that when executed by the processor perform a method for constructing a database for locating a device in three dimensional space, the method comprising:

identifying, in three dimensional space, a plurality of locations comprising an X coordinate, a Y coordinate, and a respective plurality of Z coordinates, wherein each of the plurality of Z coordinates corresponds to a respective altitude having the X coordinate and the Y coordinate;

receiving, at a first reception site, a plurality of signals, each signal of the plurality of signals being indicative of a mobile device being positioned at a respective location of the plurality of locations;

determining a metric for each signal of the plurality of signals received at the first reception site; and

constructing the database comprising, for each of the plurality of locations, the X coordinate, the Y coordinate, a respective Z coordinate, and a respective metric.

11. The processor of claim 10, wherein the database is further constructed to comprise a description of each of the plurality of locations.

12. The processor of claim 10, wherein the metric comprises at least one of:

an angle of arrival of each signal;

or

a time period for each signal to travel from a respective one of the plurality of locations to the first reception site.

13. The processor of claim 10, further comprising:

determining additional metrics for each signal of the plurality of signals; and

constructing the database respectively comprising the additional metrics.

14. The processor of claim 13, wherein the additional metrics comprise at least one of:

an angle of arrival of each signal;

or

a time period for each signal to travel from a respective one of the plurality of locations to the first reception site.

15. The processor of claim 10, further comprising:

receiving, at at least one additional reception site, the plurality of signals, each signal of the plurality of signals being indicative of a mobile device being positioned at a respective location of the plurality of locations;

determining a metric for each signal of the plurality of signals received at the at least one additional reception site; and

constructing the database further comprising a respective metric determined for a respective signal received at the at least one additional reception site.

16. The processor of claim 15, wherein the metric comprises at least one of:

an angle of arrival of each signal;

or

a time period for each signal to travel from a respective one of the plurality of locations to a respective reception site.

17. The processor of claims 15, further comprising:

determining additional metrics for each signal of the plurality of signals received at each respective reception site; and

constructing the database respectively comprising the additional metrics.

18. The processor of claim 17, wherein the additional metrics comprise at least one of:

an angle of arrival of each signal;

or

a time period for each signal to travel from a respective one of the plurality of locations to a respective reception site.