Wireless Station Sleep Duration Control for Handover Reliability

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Solution Overview

Problem

In wireless communication systems, stations (STA) often disconnect due to the sleep mechanism, where they cannot be woken up or discovered by other access points when they move out of range, leading to disconnection and reliability issues.

Innovation Solution

A method where a downlink control signal with maximum allowable sleep duration data is sent to the station, allowing it to wake up and change associated access points, thereby preventing disconnection and improving reliability by actively managing handovers and re-association attempts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the STA enters sleep mode to reduce energy consumption, then energy efficiency is improved, but the STA becomes difficult to wake up and maintain connectivity when moving out of AP range

Engineering Contradiction:

Improveenergy consumptionVSAvoidconnectivity reliability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies preliminary action by having the STA proactively send a probe request before entering sleep mode to detect nearby APs. This advance detection ensures that the STA can quickly reassociate with a new AP upon waking up, preventing disconnection and maintaining reliability while still allowing extended sleep periods for energy savings.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where the STA receives probe response information from nearby APs before sleeping, and uses this information to determine whether to enter sleep mode and which AP to reassociate with. This feedback loop ensures reliable reconnection while managing energy consumption effectively.

Inventive Principle:

Principle #23Feedback

2Reliability

If the STA remains awake continuously to maintain connectivity, then connectivity reliability is improved, but energy consumption increases significantly

Engineering Contradiction:

Improveconnectivity reliabilityVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies partial action by having the STA perform only essential connectivity-maintenance actions (sending periodic probe requests) rather than maintaining full communication activity. This allows the STA to enter sleep mode with minimal energy consumption while still ensuring reliable reconnection when needed.

Inventive Principle:

Principle #16Partial or excessive action

3Use of energy by moving object

If the STA enters deep sleep to maximize energy savings, then energy efficiency is improved, but the STA cannot be discovered or woken up by other APs

Engineering Contradiction:

Improveenergy consumptionVSAvoidAP discovery capability

Core Design Contradiction:

Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The patent applies preliminary action by having the STA send probe requests before entering deep sleep mode to discover and record information about nearby APs. This advance preparation ensures that the STA can quickly reassociate with a discovered AP upon waking, maintaining adaptability while enabling deep sleep for maximum energy savings.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11218962B2Wireless communication method and wireless communications device

Publication Date: 2022.01.04 HUAWEI TECH CO LTD

AI summary

A wireless communication method and a wireless communications device includes an access point that sends a downlink control signal to a station associated with the access point, and the station receives the downlink control signal from the access point associated with the station, where the downlink control signal includes data of maximum allowable sleep duration corresponding to the station, and a wake-up receiver wakes up the station when sleep duration of the station reaches the maximum allowable sleep duration.