Ethernet PHY Energy Saving via Dynamic Frequency Adjustment

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Solution Overview

Problem

Current Ethernet AVB transport protocols in motor vehicles face challenges in implementing energy-saving modes without causing uncontrolled delays and quality of service (QoS) losses, particularly due to fixed activation and deactivation times that lead to unnecessary power consumption.

Innovation Solution

Dynamic adjustment of transmission frequency and data content to extend the transmission cycle, allowing transceivers to enter a sleep mode while maintaining QoS by reducing the transmission frequency to a predetermined limit value, which can be inversely calculated from the sum of deactivation and activation times, and optionally reducing data resolution or channels for further energy savings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the transmission frequency is increased to maintain QoS, then data transmission quality is improved, but energy consumption increases

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

Solution Approach 1:

The patent applies dynamics by making the transmission frequency adjustable rather than fixed. The control unit dynamically adapts the transmission frequency based on QoS requirements and energy consumption targets, allowing the system to optimize between reliability and energy usage in real-time conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the transmission frequency parameter to resolve the contradiction. By reducing the transmission frequency to a calculated limit value, the system decreases energy consumption while maintaining acceptable QoS, directly addressing the trade-off between these two parameters

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If the transmission cycle is extended to save energy, then energy consumption is reduced, but transmission delays increase

Engineering Contradiction:
Improveenergy consumptionVSAvoidtransmission delay
Core Design Contradiction:
Loss of energyVSLoss of time

Solution Approach 1:

The patent applies preliminary action by calculating the limit value for transmission frequency before actual transmission occurs. The control unit determines the maximum allowable transmission cycle based on QoS requirements in advance, ensuring that energy-saving transmissions do not exceed acceptable delay thresholds

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent prevents excessive transmission delays by establishing a preliminary constraint on the transmission cycle extension. The limit value calculation inherently counteracts the tendency to extend cycles too far, maintaining a balance between energy savings and acceptable timing

Inventive Principle:
Principle #9Preliminary anti-action

3Use of energy by stationary object

If the transmission frequency is reduced to enter sleep mode, then energy consumption is reduced, but QoS may be compromised

Engineering Contradiction:
Improvepower consumptionVSAvoidQoS
Core Design Contradiction:
Use of energy by stationary objectVSReliability

Solution Approach 1:

The patent implements feedback by continuously monitoring QoS requirements and adjusting the transmission frequency accordingly. The control unit uses QoS feedback to determine whether reducing transmission frequency to enable sleep mode will maintain acceptable service quality, creating a closed-loop control system

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary calculation of the limit value for transmission frequency reduction before actually entering sleep mode. This ensures that QoS requirements are evaluated in advance, preventing quality compromise while enabling energy-saving operations

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2847942B1Method for transmitting data between nodes of a motor vehicle using an ethernet transport protocol and control unit configured to carry out said method
Publication Date: 2020.01.15 CONTINENTAL AUTOMOTIVE GMBH
  • EP2847942B1 patent drawingFigure 1~2
  • EP2847942B1 patent drawingFigure 3~5

AI summary

The invention relates to a method for transmitting data in a motor vehicle from an application between nodes of the motor vehicle using an Ethernet transport protocol and to a correspondingly configured control unit. According to said method, data is sent from the application at cyclic intervals via an Ethernet-based network and the local transmitters and receivers (PHY) of a node are de-activated in non-usage periods in which no data is to be transmitted and re-activated if data for transmission is waiting. In a de-activation period (Ts) the local transmitters and receivers (PHY) are converted from an operating mode (active) into an idle mode (LPI) and in an activation period (Tw) are converted from the idle mode (LPI) into operating mode (active). In addition, according to the invention, at a request for saving energy the transmission frequency is reduced by the application at least until a predetermined threshold is reached.