# US 9,521,645 B1 · Method and apparatus for filtering access points for WiFi positioning

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 9,521,645 B1
- Document ID: US9521645B1
- Status: Granted
- Kind: B1
- Application number: 14/291,479
- Filed: 2014-05-30
- Granted: 2016-12-13
- Earliest claimed: 2013-05-31
- Assignees: Marvell International Ltd.
- Applicants: Marvell International Ltd.
- Inventors: Xing Zhao; Thandapani Venkataramani; Jing Yu; Zhike Jia
- Web page: https://patentgrep.com/patent/US9521645B1

## CPC

- H04W 64/00: Locating users or terminals {or network equipment} for network management purposes, e.g. mobility management
- G01S 5/0205: {Details}
- G01S 5/0242: {Determining the position of transmitters to be subsequently used in positioning (G01S5/0289 takes precedence)}
- G01S 5/0263: {by combining or switching between positions derived from two or more separate positioning systems}
- H04W 84/005: {Moving wireless networks}
- H04W 84/02: Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES

## Abstract

Systems, methods, and other embodiments associated with determining a position of a device are described. According to one embodiment, a method for determining a position of a device is disclosed. The method includes detecting access points and classifying one or more of the access points as being either fixed or mobile. An access point classified as being mobile indicates that the access point is mobile. An access point classified as being fixed indicates that the access point is located at a fixed position. The method also includes determining a position of the device based, at least in part, on one or more channel powers of signals respectively received from one or more access points classified as being fixed. In this manner, the position of the device is not determined based on channel powers of signals received from access points classified as being mobile.

## Claims

### Claim 1

A device, comprising:
positioning logic configured to receive respective positions of a plurality of access points; and
monitoring logic configured to classify a respective one of the plurality of access points as being mobile or fixed according to i) a hybrid position of the device determined independent of the respective one of the plurality of access points and ii) a recorded position of the respective one of the plurality of the access points,
wherein the monitoring logic is configured to classify an access point as being mobile when a difference between the hybrid position of the device and the recorded position of the access point exceeds a threshold, wherein the monitoring logic is configured to determine the threshold according to a statistical distribution of a positioning error, and wherein an access point is classified as being fixed when the access point is located at a fixed position;
wherein the positioning logic is further configured to determine a position of the device according to:
i) channel powers of signals received from access points of the plurality of access points classified as being fixed and
ii) fixed positions of the access points classified as being fixed, and
wherein the positioning logic is configured to ignore positions of access points of the plurality of access points classified as being mobile when determining the position of the device.

### Claim 2 (depends on 1)

The device of claim 1, wherein the monitoring logic is configured to, for each access point of the plurality of access points:
access a database that stores classifications for access points that indicate whether each of the plurality of access points is fixed or mobile;
identify, in the database, a stored classification that is mapped to a MAC identifier for each of the plurality of access points; and
classify each of the plurality of the access points based, at least in part, on the stored classification.

### Claim 3 (depends on 2)

The device of claim 2, wherein the monitoring logic is configured to:
classify one of the plurality of access points as being either fixed or mobile; and
store the determined classification, mapped to a media access control (MAC) address for the one of the plurality of access points, in the database.

### Claim 4 (depends on 2)

The device of claim 2, comprising a server side decision logic implemented in a server, wherein the server side decision logic is configured to:
classify an access point as being either fixed or mobile based, at least in part, on a present position of the access point and a recorded position of the access point stored in a position database; and
store the classification, mapped to a media access control (MAC) address for the access point, in the database.

### Claim 5 (depends on 1)

The device of claim 1, wherein the hybrid position of the device is determined based, at least in part, on one or more of microelectromechanical system sensor data, global navigation satellite system (GNSS) measurement data, cellular transceiver received signal strength (RSS) data, or WiFi channel strength data for a fixed access point.

### Claim 6 (depends on 1)

The device of claim 1, wherein the monitoring logic is configured to:
access a database that stores access point position data; and
retrieve the recorded position of the respective one of the plurality of access points that is being classified as being fixed or mobile.

### Claim 7

A method, comprising:
detecting, in a device, a plurality of access points;
classifying one or more access points of the plurality of access points as being either fixed or mobile according to i) a hybrid position of the device determined independent of the one or more access points of the plurality of access points and ii) a recorded position of the one or more access points, wherein an access point is classified as being mobile when a difference between the hybrid position of the device and the recorded position of the access point exceeds a threshold,
wherein classifying the one or more access points includes determining the threshold according to a statistical distribution of a positioning error, and wherein the access point is classified as mobile to indicate that the access point changes positions, and wherein the access point is classified as being fixed to indicate that the access point is located at a fixed position; and
determining a position of the device according to channel powers of signals received from one or more of the plurality of access points classified as being fixed; and
wherein determining the position of the device includes ignoring positions of access points of the plurality of access points classified as being mobile.

### Claim 8 (depends on 7)

The method of claim 7, further comprising classifying an access point of the plurality of access points by:
accessing a database that stores classifications for the plurality of access points;
identifying, in the database, a stored classification that is mapped to a MAC identifier for the access point; and
classifying the access point based, at least in part, on the stored classification.

### Claim 9 (depends on 8)

The method of claim 8, further comprising:
classifying an access point of the plurality of access points as being either fixed or mobile; and
storing the determined classification, mapped to a media access control (MAC) address for the access point, in the database.

### Claim 10 (depends on 7)

The method of claim 7, wherein the hybrid position of the device is determined based, at least in part, on one or more of microelectromechanical system sensor data, global navigation satellite system (GNSS) measurement data, cellular transceiver received signal strength (RSS) data, or WiFi channel strength data for a fixed access point.

### Claim 11 (depends on 7)

The method of claim 7, further comprising accessing a position database that stores access point position data and retrieving the recorded position.

### Claim 12

A device comprising:
a wireless transceiver; and
an application processor comprising:
positioning logic configured to receive respective positions of a plurality of access points; and
monitoring logic configured to classify a respective one of the plurality of access points as being mobile or fixed according to i) a hybrid position of the device determined independent of the respective one of the plurality of access points and ii) a recorded position of the respective one of the plurality of the access points,
wherein the monitoring logic is configured to classify an access point as being mobile when a difference between the hybrid position of the device and the recorded position of the access point exceeds a threshold, wherein the monitoring logic is configured to determine the threshold according to a statistical distribution of a positioning error, and wherein the monitoring logic classifies the access point as mobile when the access point changes positions, and wherein the monitoring logic classifies the access point as being fixed when the access point is located at a fixed position and does not change positions;
wherein the positioning logic is further configured to determine a position of the device according to:
i) channel powers of signals received from access points of the plurality of access points classified as being fixed and
ii) fixed positions of the access points classified as being fixed, and
wherein the positioning logic is configured to ignore positions of access points of the plurality of access points classified as being mobile when determining the position of the device.

### Claim 13 (depends on 12)

The device of claim 12, further comprising
at least one source of position-related data; and
a hybrid position logic configured to derive a hybrid position of the device based, at least in part, on the position-related data.

### Claim 14 (depends on 13)

The device of claim 13, wherein the at least one source of position-related data comprises one or more of a microelectromechanical sensor, a global navigation satellite system (GNSS) receiver, a cellular transceiver, or a wireless transceiver.

### Claim 15 (depends on 12)

The device of claim 12, wherein:
the device is configured to communicate with a server associated with a network to which the device belongs;
a position database is stored in memory associated with the application processor; and
the application processor is configured to synchronize the position database with a database maintained by the server that stores access point position data.