Cooperative TDD Pre-Alert Signaling for Echo-Free Ethernet PHY Links

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing bidirectional communication systems face challenges in efficiently managing concurrent data transmission over shared communication links, leading to complex designs and the need for echo cancellation circuitry, without a clear master device for time-division scheduling.

Innovation Solution

Implementing a cooperative Time-Division Duplexing (TDD) scheme using pre-alert signaling, where PHY devices exchange pre-alert signals to enforce unidirectional data transmission, allowing flexible adaptation to bandwidth needs and eliminating the need for echo cancellation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional bidirectional communication schemes are used over shared links, then data transmission can occur in both directions, but concurrent transmissions cause interference requiring complex echo cancellation circuitry

Engineering Contradiction:
Improvebidirectional communication capabilityVSAvoidecho cancellation circuitry
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by having each PHY device transmit a pre-alert signal before actual data transmission. This pre-alert mechanism reserves the communication channel in advance, allowing the receiving device to prepare for unidirectional reception and eliminating the need for complex echo cancellation circuitry while maintaining bidirectional communication capability.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If Time-Division Duplexing is implemented without pre-alert signaling, then unidirectional transmission can be enforced, but the system lacks flexibility in adapting to varying bandwidth needs

Engineering Contradiction:
Improvemultiplexing scheme enforcementVSAvoidbandwidth adaptation
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamics by allowing PHY devices to flexibly adjust transmission timing based on actual bandwidth needs. The pre-alert signaling mechanism enables dynamic adaptation where devices can transmit at different rates and durations without rigid duty cycles, while still enforcing unidirectional transmission to simplify the multiplexing scheme.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If a master device is designated for time-division scheduling, then transmission coordination is simplified, but the system loses flexibility and adaptability

Engineering Contradiction:
Improvetransmission coordinationVSAvoidflexibility in bandwidth allocation
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent applies self-service by enabling each PHY device to autonomously manage its own transmission timing through pre-alert signaling. Instead of relying on a master device for centralized scheduling, each device independently sends pre-alerts to reserve the channel, achieving both simplified coordination and flexible adaptability to varying bandwidth requirements.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4607856A1Cooperative time-division duplexing using pre-alert signaling
Publication Date: 2025.08.27 MARVELL ASIA PTE LTD
  • EP4607856A1 patent drawingFigure 1
  • EP4607856A1 patent drawingFigure 2
  • EP4607856A1 patent drawingFigure 3

AI summary

A physical layer (PHY) device, for use in an Ethernet network, includes a cable interface, a transmitter, a receiver and a processor. The cable interface connects to an Ethernet link for communicating with a peer PHY device. The transmitter transmits outbound signals that carry outbound data to the peer PHY device over the Ethernet link. The receiver receives inbound signals that carry inbound data from the peer PHY device over the Ethernet link. The processor (i) controls the transmitter to transmit, to the peer PHY device, an outbound pre-alert signal indicating that the PHY device is about to start transmitting the outbound signals, and (ii) in response to receiving, via the receiver, an inbound pre-alert signal from the peer PHY device during a period in which the peer PHY device is abstaining from transmitting the inbound signals, controls the transmitter to abstain from transmitting the outbound signals.