Flexible Data Frame Delivery via Target Wake Time Scheduling

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Solution Overview

Problem

In wireless communications networks, especially those with a large number of battery-powered stations in low power mode, data frame exchanges are inefficient due to synchronization issues and prolonged sleep periods, leading to potential data loss and increased wake-up times for stations.

Innovation Solution

The access point sends a sleep mode indication and duration to stations, scheduling a target wake time for resuming data frame exchanges, allowing stations to enter sleep mode and wake up at designated times, ensuring efficient data delivery and reducing unnecessary wake-ups.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If stations operate in low power mode for prolonged periods, then energy consumption is reduced, but synchronization is lost and wake-up time increases

Engineering Contradiction:

Improveenergy consumptionVSAvoidwake-up time

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The access point performs preliminary actions by buffering data frames before the station wakes up and sends a target wake time indication in advance. This allows the station to wake up at a predetermined time knowing data will be available, reducing unnecessary extended wake periods and optimizing energy consumption while minimizing wake-up time losses.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements feedback through the target wake time indication mechanism, where the access point informs the station of the optimal wake-up time based on buffered data availability. This feedback loop allows stations to synchronize their wake-up times efficiently, balancing energy savings with timely data reception.

Inventive Principle:

Principle #23Feedback

2Reliability

If access point buffers data for sleeping stations, then data delivery is maintained, but data exchange efficiency decreases

Engineering Contradiction:

Improvedata deliveryVSAvoiddata exchange efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The access point performs preliminary data buffering and sends target wake time indications in advance, allowing stations to wake up only when necessary. This preliminary action maintains reliable data delivery while improving efficiency by preventing unnecessary extended wake periods and reducing contention overhead from frequent wake-ups.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses periodic target wake time indications to schedule station wake-ups based on actual data availability. This periodic mechanism replaces continuous or frequent wake-ups with scheduled, efficient wake-up periods, maintaining data delivery reliability while significantly improving overall data exchange efficiency.

Inventive Principle:

Principle #19Periodic action

3Reliability

If stations wake up frequently to check for data, then data loss is minimized, but power consumption increases

Engineering Contradiction:

Improvedata loss preventionVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The access point performs preliminary actions by buffering data and sending target wake time indications before stations need to wake up. This allows stations to sleep until the predetermined wake time, preventing data loss through reliable notification while minimizing power consumption by reducing the frequency and duration of wake-up periods.

Inventive Principle:

Principle #10Preliminary action

4Loss of energy

If access point transmits beacons occasionally, then network overhead is reduced, but synchronization is lost for sleeping stations

Engineering Contradiction:

Improvenetwork overheadVSAvoidsynchronization

Core Design Contradiction:

Loss of energyVSStability of the object's composition

Solution Approach 1:

The target wake time indication serves as an intermediary mechanism between beacons and station wake-up decisions. Instead of relying solely on occasional beacons for synchronization, the access point uses this intermediary indication to provide precise wake-up timing information to stations, maintaining synchronization with minimal beacon overhead.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9374190B2Flexible data frame delivery

Publication Date: 2016.06.21 AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LTD

AI summary

A method, apparatus and computer program product are provided for enhancing data exchange between an access point (AP) and station (STA) in a wireless network when the exchange must be interrupted for the AP to perform other services while data remains buffered for later exchange. AP downlinks an indicator that more data remains for exchange together with a request for the STA to enter sleep mode for a duration scheduled by the AP. Sleep duration may be sent in the medium access control (MAC) header of a data frame, with the indicator of more data and the indicator of the sleep mode request being contained in the frame control (FC) segment of the MAC header. The STA may uplink an acknowledgement (ACK) of the sleep mode. Alternatively, the AP may downlink an ACK of the STA's indication of more data confirmation together with sleep mode indication and duration.