US 9,960,865 B2Granted

Filtering of Wi-Fi physical layer measurements

AssigneeApple Inc.

InventorsXiaowen Wang, Vinay R. Majjigi, Syed A. Mujtaba, Christopher J. Hansen

Life of this patent

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Abstract

A station (STA) can receive messages (e.g., beacon frames) at a regular interval, and perform measurements on the received messages. The STA maintains a running average of recent measurement values, and updates the running average after each new measurement interval. At some measurement opportunities, the expected messages cannot be received by the STA, and so the STA cannot perform a measurement; when this occurs, the STA can choose substitute values to use for the missed measurements when next calculating the running average. As one example, the STA can substitute the value for a previously-performed measurement for the missed measurements. As another example, the STA can substitute a predetermined low value for the missed measurements. Based on the value of the running average at a given point in time, the STA can take actions such as initiating a roaming scan or switching to a different wireless interface.

Claims19

Dependent claims

A method for use in an electronic device, the method comprising:

by the electric device:
measuring a signal at a first time to obtain a first measurement value;
when the signal is not measurable at a second time, obtaining a first substitute value using the first measurement value;
when the signal is not measurable at a third time, obtaining a second substitute value using a predetermined value;
forming a set of one or more measurement values, wherein the set of one or more measurement values comprises the first measurement value, and wherein the set of one or more measurement values is associated with successful reception of the signal during an averaging time window, each measurement value corresponding to a particular measurement interval in the averaging time window;
forming a set of two or more substitute values, wherein the set of two or more substitute values comprises the first substitute value and the second substitute value, and wherein the set of two or more substitute values is associated with unsuccessful reception of the signal for two or more consecutive measurement intervals in the averaging time window;
determining an average measurement value for the averaging time window based at least in part on the set of one or more measurement values and on the set of two or more substitute values;
and
performing a corrective action when the average measurement value satisfies a performance criterion.

6 more elements

An electronic device comprising processing circuitry configured to cause the electronic device to at least:

measure a signal at a first time to obtain a first measurement value;
when the signal is not measurable at a second time, obtain a first substitute value using the first measurement value;
when the signal is not measurable at a third time, obtain a second substitute value using a predetermined value;
form a set of one or more measurement values, wherein the set of one or more measurement values comprises the first measurement value, and wherein the set of one or more measurement values is associated with successful reception of the signal during an averaging time window, each measurement value in the set of measurement values corresponding to a particular measurement interval in the averaging time window;
form a set of two or more substitute values, wherein the set of two or more substitute values comprises the first substitute value and the second substitute value, and wherein the set of two or more substitute values is associated with unsuccessful reception of the signal for two or more consecutive measurement intervals in the averaging time window;
determine an average measurement value for the averaging time window based at least in part on the set of one or more measurement values and on the set of two or more substitute values;
and
perform a corrective action when the average measurement value satisfies a performance criterion.

5 more elements

A non-transitory computer readable medium having computer program code stored thereon, the computer program code, when executed by one or more processors on an electronic device, causes the electronic device to perform a method comprising:

receiving, from a second electronic device, a signal at a first time, a second time, and a third time over a wireless connection;
measuring the signal at the first time to obtain a first measurement value;
when the signal is not measurable at the second time, obtaining a first substitute value using the first measurement value;
when the signal is not measurable at the third time, obtaining a second substitute value using a predetermined value;
forming a set of one or more measurement values, wherein the set of one or more measurement values comprises the first measurement value, and wherein the set of one or more measurement values is associated with successful reception of the signal during an averaging time window, each measurement value corresponding to a particular measurement interval in the averaging time window;
forming a set of two or more substitute values, wherein the set of two or more substitute values comprises the first substitute value and the second substitute value, and wherein the set of two or more substitute values is associated with unsuccessful reception of the signal for two or more consecutive measurement intervals in the averaging time window;
determining an average measurement value for the averaging time window based on the set of one or more measurement values and on the set of two or more substitute values;
and
performing a corrective action when the average measurement value satisfies a performance criterion.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/152,739Filed 10 Jan 2014 · us provisional application
Priority: 10 Jan 2013
Published: US 2014/0192669 A110 Jul 2014
Granted: 1 May 2018
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

H04B 17/318
Measuring or estimating channel quality parameters: received signal strength
H04B 17/26
Of receivers: using historical data, averaging values or statistics
H04W 48/16
Access restriction ; Network selection; Access point selection: discovering, processing access restriction or access information
H04B
Transmission