Ethernet PHY Power Management via Synchronized State Transitions

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Solution Overview

Problem

Conventional Ethernet devices, particularly PHYs, consume constant power in both active and idle modes, leading to inefficient power usage, as they do not effectively transition between power states, especially in networks with multiple communication links and unpredictable traffic bursts.

Innovation Solution

A method involving synchronization of components within a communication path using protocols like IEEE1588v2 and hardware time stamping to generate and transmit power state messages, allowing components to enter low power states during periods of inactivity, thereby reducing power consumption by coordinating transitions between power states across multiple communication links.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PHYs remain in constant power mode to ensure immediate data transmission capability, then network responsiveness is maintained, but power consumption increases significantly

Engineering Contradiction:
Improvenetwork responsivenessVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic power management by allowing PHYs to transition between active and low-power states based on actual network traffic conditions. The system dynamically adjusts power consumption levels rather than maintaining a constant state, resolving the contradiction between immediate responsiveness and energy efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses wake-up frames and advance notification mechanisms to prepare PHYs for upcoming data transmissions. By receiving preliminary notification of incoming traffic, PHYs can maintain low-power states longer and transition to active state just in time, ensuring responsiveness while minimizing power consumption during idle periods.

Inventive Principle:
Principle #10Preliminary action

2Use of energy by moving object

If PHYs transition to low power states during idle periods to save energy, then power consumption decreases, but network responsiveness deteriorates

Engineering Contradiction:
Improvepower consumptionVSAvoidnetwork responsiveness
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The system sends wake-up frames in advance to notify PHYs of upcoming data transmissions. This preliminary action allows PHYs to remain in low-power states until absolutely necessary, transitioning to active state just before data arrival is expected, thus maintaining both energy savings and responsiveness.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where receiving PHYs send notifications to transmitting PHYs about their power state and readiness. This feedback loop ensures coordinated transitions and maintains network responsiveness even when PHYs are in low-power states, resolving the contradiction between energy saving and immediate response capability.

Inventive Principle:
Principle #23Feedback

3Use of energy by moving object

If power state transitions are coordinated across multiple communication links, then overall power consumption reduces, but system complexity increases

Engineering Contradiction:
Improveoverall power consumptionVSAvoidsynchronization complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent merges power management control across multiple communication links by having a central controller or coordinating entity manage transitions for multiple PHYs. This consolidation approach achieves overall power reduction while centralizing the complexity of coordination, making the system more manageable despite the increased synchronization requirements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The wake-up frame mechanism serves multiple functions simultaneously: it acts as a power state notification, a data transmission trigger, and a synchronization signal across multiple links. This multi-functionality reduces the need for separate coordination protocols, thereby limiting the increase in system complexity while achieving coordinated power management.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2340623B1Power management of a network device
Publication Date: 2019.04.24 CISCO TECHNOLOGY INC
  • EP2340623B1 patent drawingFigure 1
  • EP2340623B1 patent drawingFigure 2
  • EP2340623B1 patent drawingFigure 3

AI summary

In one embodiment, a method includes receiving a synchronization command to synchronize time information among each component of a set of components in a communication path. The method includes generating a power state message. The method includes transmitting the power state message, by the first component, to the remaining components in the communication path. The power state message is configured to reduce the power consumption of the remaining components of the set of components from a first power amount to a second power amount for a time period and the time period is associated with the synchronized time information.