WLAN Access Point Presence State Determination

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Solution Overview

Problem

Conventional wireless local area networks (WLANs) face significant challenges in maintaining presence state information for mobile communication devices, as the frequent handshaking required to update presence status consumes substantial power and network capacity, particularly in mobile devices with limited battery life and in enterprise WLANs.

Innovation Solution

Implementing a method where a WLAN access point determines the presence state of associated stations and only updates the presence server when a change occurs, reducing the need for frequent handshaking and minimizing processing burden on mobile devices by using techniques that do not require high-level application-oriented messages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If frequent handshaking is used to maintain presence information, then presence information remains current, but power consumption increases and network capacity is reduced

Engineering Contradiction:
Improvepresence information accuracyVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic presence handshaking where the access point sends presence messages to the presence server at predetermined time intervals instead of continuously. This periodic action maintains presence information accuracy while significantly reducing power consumption and network traffic compared to continuous handshaking, directly resolving the technical contradiction between reliability and energy use.

Inventive Principle:
Principle #19Periodic action

2Reliability

If frequent handshaking is used to maintain presence information, then presence information remains current, but network capacity is consumed

Engineering Contradiction:
Improvepresence information accuracyVSAvoidnetwork traffic
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The system transmits presence information from the access point to the presence server at periodic intervals rather than continuously. This reduces the quantity of network traffic while maintaining current presence information, resolving the contradiction between reliability and network capacity consumption.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent extracts the presence monitoring function from the mobile device and relocates it to the access point. The access point independently monitors station presence and reports to the server, eliminating the need for the device to participate in frequent handshaking. This extraction reduces network traffic while maintaining presence accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If presence handshaking is performed on mobile devices, then presence information is maintained, but processing burden on device increases

Engineering Contradiction:
Improvepresence information accuracyVSAvoidprocessing burden
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the presence monitoring functionality from the mobile device and transfers it to the access point. The access point now performs presence determination and communicates with the presence server, while the mobile device simply responds to presence messages from the access point. This extraction significantly reduces the processing burden on the device while maintaining presence information accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The access point acts as an intermediary between the mobile device and the presence server. Instead of the device directly communicating with the server for presence updates, the access point mediates this communication by monitoring presence and reporting to the server. This intermediary role reduces the device's processing burden while maintaining accurate presence information.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2520071B1Method and apparatus for updating presence state of a station in a wireless local area network (WLAN)
Publication Date: 2014.03.26 MOTOROLA SOLUTIONS INC
  • EP2520071B1 patent drawingFigure 1
  • EP2520071B1 patent drawingFigure 2~3
  • EP2520071B1 patent drawingFigure 4

AI summary

A method and apparatus for presence state determination at an access point of a station determines whether a station associated with the access point is responsive to the access point to indicate the station is "present" or "not present". The access point informs a presence server when the station's presence state changes. The presence server does not therefore need to rely on presence handshaking between the presence server and the station.