Ethernet PHY Data Rate Scaling for Extended Cable Reach

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Solution Overview

Problem

Current Ethernet technologies, such as 1000BASE-T and 10GBASE-T, are limited to a maximum cable length of 100 meters, which is insufficient for newer applications requiring longer distances and higher data rates, and existing solutions increase complexity and power consumption.

Innovation Solution

The implementation of a network interface module that reduces transmit and receive data rates while maintaining the physical coding sublayer, error correction, and signaling schemes, allowing for cable lengths greater than 100 meters by using a data rate divisor to scale down data rates, and optionally incorporating a cable measurement module and clock reduction circuit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If conventional Ethernet solutions are used to achieve longer cable lengths, then the reach is extended, but device complexity and power consumption increase

Engineering Contradiction:
Improvecable lengthVSAvoiddevice complexity
Core Design Contradiction:
Length of stationary objectVSDevice complexity

Solution Approach 1:

The patent changes the data rate parameter from standard 1000 Mbps or 10 Gbps to reduced rates (e.g., 125 Mbps, 250 Mbps, 500 Mbps, or 1 Gbps) to enable longer cable lengths. This parameter change allows the existing physical layer to operate successfully over distances exceeding 100 meters without requiring more conductors or cables, thereby extending reach while avoiding increased device complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements dynamic data rate adjustment through autonegotiation between two network devices. The system can automatically select appropriate data rates based on cable length and conditions, transitioning between different operational modes (e.g., 1000base-T for short distances, 100base-T for longer distances). This dynamic adaptation enables the system to optimize performance for each specific deployment scenario without requiring manual configuration or complex hardware changes

Inventive Principle:
Principle #15Dynamics

2Length of stationary object

If conventional Ethernet solutions are used to achieve longer cable lengths, then the reach is extended, but power consumption increases

Engineering Contradiction:
Improvecable lengthVSAvoidpower consumption
Core Design Contradiction:
Length of stationary objectVSUse of energy by stationary object

Solution Approach 1:

The patent reduces the data rate parameter from high-speed modes (1000 Mbps or 10 Gbps) to lower rates, which directly reduces the power consumption of the physical layer transceiver. Operating at reduced data rates requires less power for signal generation and reception, enabling longer cable lengths without the power consumption penalties associated with high-speed Ethernet over extended distances

Inventive Principle:
Principle #35Parameter changes

3Length of stationary object

If data rate is reduced to extend cable length, then reach is increased, but data transfer speed decreases

Engineering Contradiction:
Improvecable lengthVSAvoiddata transfer rate
Core Design Contradiction:
Length of stationary objectVSSpeed

Solution Approach 1:

The patent implements dynamic data rate selection through autonegotiation, allowing the system to automatically adjust the operating speed based on cable length and conditions. For short cables, the system operates at full speed (1000 Mbps or 10 Gbps); for longer cables, it dynamically transitions to reduced rates. This dynamic adaptation ensures optimal performance for each deployment scenario, maximizing data transfer speed when possible while enabling extended reach when necessary

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the data rate parameter dynamically based on operational requirements. By selecting appropriate data rates (e.g., 125 Mbps, 250 Mbps, 500 Mbps, or 1 Gbps) based on cable length, the system achieves a balance between reach and speed. This parameter change allows the system to extend cable length when needed while maintaining acceptable data transfer rates for most applications

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2223457B1Long-reach ethernet for 1000base-t and 10gbase-t
Publication Date: 2021.03.03 MARVELL ASIA PTE LTD
  • EP2223457B1 patent drawingFigure 1
  • EP2223457B1 patent drawingFigure 2~4
  • EP2223457B1 patent drawingFigure 5

AI summary

A physical-layer device (PHY) having corresponding methods comprises: a data rate module to select a data rate divisor N, where N is at least one of a positive integer, or a real number greater than, or equal to, 1; and a PHY core comprising a PHY transmit module to transmit first signals a data rate of M/N Gbps, and a PHY receive module to receive second signals at the data rate of M/N Gbps; wherein the first and second signals conform to at least one of 1000BASE-T, wherein M = 1, and 10GBASE-T, wherein M = 10.