PHY Wake-Up Mechanism for Energy Efficient Ethernet Networks

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Solution Overview

Problem

Conventional Ethernet networks face inefficiencies due to continuous transmission of IDLE symbols at fixed data rates, leading to underutilization of network links and increased power consumption, especially during periods of low data transmission.

Innovation Solution

Implementing a PHY-initiated wake-up mechanism that allows Ethernet network devices to transition between active and low-power modes based on link utilization, using wake state idle symbols to manage data rate limits and control noise cancellation, enabling energy-efficient operation by reducing unnecessary active state IDLE symbol transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If continuous transmission of IDLE symbols is maintained at fixed data rates, then link stability is preserved, but power consumption increases and network efficiency decreases during low utilization periods

Engineering Contradiction:

Improvelink stabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic data rate adjustment where the Ethernet PHY device transitions between different operating modes (active, low-power, and power-save states) based on link utilization. The system dynamically changes transmission characteristics by sending wake-up symbols at reduced data rates during low utilization periods, thereby adapting the system behavior to current conditions rather than maintaining fixed parameters.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes key operating parameters including data rate, power mode, and symbol transmission characteristics based on monitored link conditions. The PHY device monitors link utilization and accordingly adjusts parameters such as transitioning from full data rate active state to reduced data rate low-power state, and modifies IDLE symbol transmission patterns to reduce power consumption while maintaining link stability.

Inventive Principle:

Principle #35Parameter changes

2Stability of the object's composition

If continuous transmission of IDLE symbols is maintained at fixed data rates, then link synchronization is maintained, but network efficiency decreases during periods of low data transmission

Engineering Contradiction:

Improvelink synchronizationVSAvoidnetwork efficiency

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The system dynamically adjusts IDLE symbol transmission characteristics based on link utilization. During low utilization periods, the PHY device reduces transmission activity by entering low-power modes and sending wake-up symbols at reduced data rates, thereby improving network efficiency while maintaining sufficient synchronization through periodic wake-up signals rather than continuous transmission.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

Instead of continuous IDLE symbol transmission, the patent implements periodic wake-up symbol transmission. The PHY device monitors link conditions and sends wake-up symbols periodically at reduced data rates during low utilization periods, maintaining link synchronization through periodic rather than continuous action, thus improving overall network efficiency.

Inventive Principle:

Principle #19Periodic action

3Use of energy by moving object

If wake-up symbols are transmitted at reduced data rates, then energy consumption is reduced, but link stability may be compromised

Engineering Contradiction:

Improveenergy consumptionVSAvoidlink stability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The PHY device continuously monitors link utilization and quality parameters to determine when to transition between active and low-power states. This feedback mechanism ensures that wake-up symbols are transmitted at reduced data rates only when link conditions permit, thereby reducing energy consumption while maintaining link stability through condition-based decision making rather than blanket reduction.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system maintains buffer capacity and synchronization state during low-power periods to cushion against potential link instability. By preserving essential link state information and readiness to quickly transition back to active state, the system compensates for the reduced transmission activity during low-power modes, ensuring link stability is maintained despite energy-saving measures.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS8769082B2Method and system for PHY initiated wake-up in energy efficient ethernet networks

Publication Date: 2014.07.01 AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LTD

AI summary

One or both link partners coupled via an Ethernet link may comprise a PHY device operable to initiate a wake-up interval. The PHY device may monitor parameters that may indicate Ethernet link status. Exemplary parameters may comprise a timer, communication performance metrics and/or configuration parameters. From a low power mode, the PHY device may generate a wake state idle symbol based on the monitoring and may communicate it to a local and/or a remote MAC. The local and/or remote MAC may establish a wake-up interval. The wake-up interval may comprise synchronization, circuit adaption and updating of communication parameters, which may enable control of noise cancellation functions and/or equalization functions. One or both of the link partners may transition to a low power mode after the wake-up interval and/or to an active state after the wake-up interval.