Wireless LAN Wake-Up Controller Using Segmented Power and Periodic Scanning

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Solution Overview

Problem

Existing technologies face challenges in waking wireless computing devices from a powered-down or sleep state over wireless local area networks due to the portable nature of these devices and the difficulty in addressing wake-up signals to specific devices within a wireless LAN.

Innovation Solution

A system and method for wirelessly waking devices from a reduced power mode by scanning multiple wireless channels for a wake-up data sequence, using a wireless network controller with a transceiver, power control circuitry, and a comparator to identify and respond to a MAGIC PACKET-like sequence, allowing devices to be powered up when the correct sequence is received.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If wireless devices are put into reduced power mode to save energy, then energy consumption is reduced, but the ability to receive wake-up signals is lost

Engineering Contradiction:

Improveenergy consumptionVSAvoidability to receive wake-up signals

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The wireless device is segmented into multiple functional components with different power requirements. The network controller is kept in a low-power state while the receiver remains active to monitor for wake-up signals. When a wake-up signal is detected, power is then restored to the network controller. This segmentation allows the device to save energy while maintaining the ability to be awakened.

Inventive Principle:

Principle #1Segmentation

2Reliability

If the receiver continuously monitors all wireless channels for wake-up signals, then the device can be reliably woken up, but energy consumption increases

Engineering Contradiction:

Improvewake-up signal detectionVSAvoidreceiver power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

Instead of continuously monitoring all wireless channels, the receiver periodically scans through the channels in sequence. The receiver activates for predetermined time periods to monitor specific channels, then enters a low-power state. This periodic scanning approach maintains the ability to detect wake-up signals while significantly reducing overall power consumption compared to continuous monitoring.

Inventive Principle:

Principle #19Periodic action

3Adaptability or versatility

If the device scans multiple wireless channels to find the correct one, then compatibility with different wireless networks is improved, but the time to wake up the device increases

Engineering Contradiction:

Improvenetwork compatibilityVSAvoidwake-up time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The receiver is pre-configured with information about which wireless channels to monitor and the sequence in which to scan them. This preliminary setup allows the receiver to efficiently scan through channels without requiring complex real-time decision-making. The wake-up signal includes channel information that guides the receiver to the correct channel, reducing the time needed to establish communication.

Inventive Principle:

Principle #10Preliminary action

4Reliability

If the network controller remains active to receive wake-up signals, then the device can be woken up reliably, but energy savings are reduced

Engineering Contradiction:

Improvewake-up functionalityVSAvoidnetwork controller power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The receiver acts as an intermediary component that remains active in a low-power state to monitor for wake-up signals. When a signal is detected, the receiver then activates the network controller. This intermediary approach allows the network controller to remain inactive and save energy while still enabling reliable wake-up functionality through the receiver's monitoring capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS8156360B2Systems and methods for waking wireless LAN devices

Publication Date: 2012.04.10 INTEGRAL WIRELESS TECHNOLOGIES LLC

AI summary

A system and method for wireless waking computing devices over a computer network is provided. A signal is broadcast over the network that includes one or more device specific wake-up data sequences. Each device specific wake-up data sequence includes multiple iterations of the hardware address of the wireless network card associated with that device. While in a reduced power or “sleep mode”, the wireless network card monitors wireless channels for packets containing a wake-up data sequence. If a wake-up data sequence is received, the sequence is matched against the hardware address information for that network card. If a match is determined, the network card sends a signal to the computing device causing full system power to be restored. A signal is sent to the network confirming that the device has been successfully woken from the sleep mode.