Passive Optical Data Center Routing for Low-Power Bandwidth Scaling

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Solution Overview

Problem

Conventional data center networks face performance limitations such as link oversubscription and inefficient load balancing, leading to high power consumption and environmental impact due to the use of power-hungry devices like access and aggregation switches.

Innovation Solution

Implementing a passive optical-based data center network architecture that utilizes passive optical routing elements and time-division multiplexing (TDM) or wavelength-division multiplexing (WDM) to reduce the need for active elements, allowing intra-group and inter-group communication without routing through power-hungry switches, and using hybrid TDM-WDM for enhanced bandwidth utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If conventional data center networking architectures with access and aggregation switches are used, then connectivity and routing flexibility are provided, but power consumption increases and performance limitations such as link oversubscription occur

Engineering Contradiction:
Improvepower consumptionVSAvoidnetworking architecture complexity
Core Design Contradiction:
Use of energy by stationary objectVSDevice complexity

Solution Approach 1:

The patent extracts and removes active switching elements (access switches and aggregation switches) from the data center network architecture. By eliminating these power-hungry devices and replacing them with passive optical components, the system achieves significant power consumption reduction while maintaining network functionality through passive optical routing and wavelength-division multiplexing

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent substitutes mechanical/electronic switching systems with optical-based passive routing systems. Instead of using active electronic switches that consume power, the invention employs passive optical components such as optical splitters, combiners, and wavelength multiplexers that route signals without requiring electrical power, thereby replacing the mechanical-electronic system with an optical system

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If passive optical-based architecture is implemented, then power consumption is reduced and bandwidth efficiency is improved, but device complexity and implementation challenges increase

Engineering Contradiction:
Improvebandwidth efficiencyVSAvoidoptical routing complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements a universal passive optical network architecture that handles multiple functions (routing, switching, multiplexing) through a single integrated passive optical infrastructure. The wavelength-division multiplexing system provides a unified framework that can simultaneously manage intra-rack and inter-rack communications, eliminating the need for separate active switching fabrics and improving bandwidth efficiency across the entire data center

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

3Speed

If active switching elements are used for routing, then flexible routing and load balancing are achieved, but link oversubscription and performance limitations occur

Engineering Contradiction:
Improvedata transmission speedVSAvoidnetwork performance reliability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent introduces wavelength as an additional dimension for data transmission, transitioning from traditional single-wavelength Ethernet switching to multi-wavelength optical networking. By utilizing multiple wavelengths simultaneously over the same physical infrastructure, the system achieves higher data transmission speeds and eliminates link oversubscription without requiring complex active routing logic, thereby improving both speed and reliability

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Reduces power consumption and congestion by minimizing the use of active devices, improving connectivity and bandwidth efficiency, and reducing the need for costly laser diodes at servers.

Implementation Method 1

a first lower passive optical routing element 120a for routing optical communication signals between a first group of servers 140a and a first lower optical communication path 130a

Methodology Applied
Scientific EffectOptical reflection: Reflection

Implementation Method 2

a first lower passive optical routing element 120a for routing optical communication signals between a first group of servers 140a and a first lower optical communication path 130a

Methodology Applied
Scientific EffectOptical refraction: Refraction

Implementation Method 3

utilizes passive optical routing elements and time-division multiplexing (TDM) or wavelength-division multiplexing (WDM)

Methodology Applied
Scientific EffectTime-division multiplexing:

Implementation Method 4

utilizes passive optical routing elements and time-division multiplexing (TDM) or wavelength-division multiplexing (WDM)

Methodology Applied
Scientific EffectWavelength-division multiplexing:

Data Source

PatentEP4293936B1Passive optical-based data center networks
Publication Date: 2025.12.31 UNIVERSITY OF LEEDS
  • EP4293936B1 patent drawingFigure 1
  • EP4293936B1 patent drawingFigure 2
  • EP4293936B1 patent drawingFigure 3a~3c

AI summary

A data centre network, comprises a first group of optical ports for connection to respective servers of a first group of servers; a second group of optical ports for connection to respective servers of a second group of servers; a first lower passive optical routing element arranged to route optical communication signals between the first group of optical ports and a first lower optical communication path; a second lower passive optical routing element arranged to route optical communication signals between the second group of optical ports and a second lower optical communication path; an upper passive optical routing element arranged to: (i) route optical communication signals between the first lower optical communication path and an upper optical communication path, and (ii) route optical communication signals between the second lower optical communication path and the upper optical communication path.