Intermediary Device Emulating Wake on LAN for Energy Efficient Ethernet

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Solution Overview

Problem

Existing Ethernet systems fail to achieve significant energy savings when computing devices enter a sleep state with Wake on LAN (WoL) enabled, as the network interface remains active, preventing intermediary devices from powering down and thus missing opportunities for energy conservation.

Innovation Solution

An intermediary device between a computing device and a network transitions the network interface from an active state to an energy-saving state when the computing device enters a sleep state, and reactivates it only when a Wake on LAN message is detected, allowing the intermediary device to power down unless a WoL packet is destined for the sleeping device, thereby emulating WoL and saving energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the network interface remains active to support Wake on LAN functionality, then the computing device can be awakened from sleep state, but the network interface consumes energy preventing significant energy savings

Engineering Contradiction:
Improveenergy consumption of network interfaceVSAvoidwake on LAN functionality
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent introduces an intermediary device (such as a switch or gateway) that acts as a mediator between the sleeping computing device and the network. This intermediary monitors incoming traffic and forwards wake-up packets to the device's memory or registers even when the network interface is powered down, thereby enabling wake-on-LAN functionality while allowing the network interface to enter low-power states and achieve energy savings.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If the network interface transitions to energy saving state, then energy consumption is reduced, but the device cannot receive wake up messages

Engineering Contradiction:
Improveenergy consumption of network interfaceVSAvoidwake up capability
Core Design Contradiction:
Use of energy by moving objectVSEase of operation

Solution Approach 1:

The patent implements preliminary action by having the intermediary device capture and buffer wake-up packets before the computing device wakes up. The intermediary monitors the network for wake-up traffic patterns and stores these packets in the device's memory or registers in advance, so that when the device transitions from sleep state, the wake-up messages are already available, enabling seamless wake-up capability without requiring the network interface to remain active.

Inventive Principle:
Principle #10Preliminary action

3Use of energy by moving object

If the computing device enters sleep mode, then energy savings are achieved in the computing device, but the network interface must remain active to maintain Wake on LAN

Engineering Contradiction:
Improveenergy consumption of computing deviceVSAvoidenergy consumption of network interface
Core Design Contradiction:
Use of energy by moving objectVSUse of energy by stationary object

Solution Approach 1:

The patent applies segmentation by separating the wake-up functionality from the network interface itself. The wake-up packet reception and processing functions are divided into different components: the intermediary device handles network monitoring and packet capture, while the computing device's memory or registers store the wake-up packets. This segmentation allows the network interface to be completely powered down during sleep mode, achieving energy savings in both the computing device and the network interface simultaneously.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2224311B1System and method for energy savings through emulation of wake on lan in energy efficient ethernet
Publication Date: 2014.04.09 BROADCOM INC
  • EP2224311B1 patent drawingFigure 1
  • EP2224311B1 patent drawingFigure 2
  • EP2224311B1 patent drawingFigure 3

AI summary

A system and method for energy savings through emulation of wake on LAN (WoL) in energy efficient Ethernet networks. An intermediary device between a computing device and a network can be alerted that the computing device has entered an energy saving state with wake on LAN (WoL) enabled. The intermediary device can transition the client interface that supports the computing device into an energy saving state and emulate the WoL function of the computing device by listening for a WoL message destined for the computing device. Upon receipt of a WoL message destined for the computing device, the intermediary device can transition the client interface back to an active state then transmit the received WoL message to the computing device.