Passive Optical Switching Fabric for Low-Latency Data Centers

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Solution Overview

Problem

Existing IP Clos switching topologies in cloud gaming and data centers face challenges with high capital and operational costs, complexity, and increased latency due to the use of spine dedicated devices and transceivers, which are not efficiently scalable and introduce additional failure points.

Innovation Solution

Implementing an optical data center fabric (ODCF) with passive optical power splitters to replace traditional switches, providing an express path between the data center edge and leaf nodes, reducing latency and complexity while lowering costs through the use of flexible optical technologies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional IP Clos switching topologies with spine dedicated devices are used, then host connectivity and routing flexibility are achieved, but capital costs, operational costs, and device complexity increase rapidly

Engineering Contradiction:
Improvehost connectivityVSAvoidnumber of spine devices
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the active switching function from the intermediate spine layer and replaces it with passive optical components. Specifically, the optical splitter replaces traditional spine switches, eliminating the need for complex routing logic in the intermediate layer while maintaining connectivity between edge and leaf nodes through pure optical signal distribution

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent substitutes electronic/optical-electronic switching mechanisms with pure optical mechanisms. By using optical splitters instead of electronic switches in the spine layer, the system eliminates O-E-O conversions and electronic routing complexity, achieving a more efficient optical-dominated architecture that reduces both device count and operational complexity

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

2Adaptability or versatility

If 5 stage or greater CLOS switching topologies are deployed to deliver required host connectivity, then routing flexibility is maintained, but the number of spine dedicated devices and transceivers explodes

Engineering Contradiction:
Improverouting flexibilityVSAvoidnumber of devices and transceivers
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent uses optical signal copying through passive splitters to distribute traffic to multiple leaf nodes simultaneously. Instead of requiring separate physical paths through multiple stages of switches, a single optical signal is copied and distributed to all necessary destinations, dramatically reducing the number of devices and transceivers needed while maintaining full routing flexibility

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent transitions from a multi-stage electronic switching dimension to a pure optical distribution dimension. By implementing an optical spine layer that operates independently of electronic routing stages, the system adds an optical dimension to the architecture that parallelizes signal distribution and eliminates the need for sequential electronic switching stages

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

3Ease of operation

If intermediate switch layers are used in optical data center fabric, then signal distribution and routing control are achieved, but latency increases and scalability is reduced

Engineering Contradiction:
Improvesignal distributionVSAvoidlatency
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent introduces passive optical splitters as intermediaries between edge and leaf nodes, replacing active electronic switches. These optical splitters mediate signal distribution without requiring power, processing, or active control, enabling direct optical paths that minimize latency while maintaining ease of signal distribution through the intermediary optical layer

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent extracts the active control function from the intermediate layer, leaving only passive optical signal distribution. By removing electronic processing and active routing control from the spine layer, the system eliminates the latency associated with electronic switching operations while maintaining signal distribution capability through pure optical means

Inventive Principle:
Principle #2Taking out (Extraction)

4Area of stationary object

If spine dedicated devices are deployed, then network coverage and connectivity are expanded, but operational complexity and active failure points increase

Engineering Contradiction:
Improvenetwork coverageVSAvoidnumber of failure points
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent replaces expensive, complex electronic spine switches with inexpensive passive optical splitters. These passive components have no moving parts, no power requirements, and no software, making them inherently more reliable with no failure points while maintaining network coverage through their passive optical distribution capability

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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

The ODCF reduces capital and operational expenditures, simplifies networking, and enhances scalability by eliminating intermediate switch layers with passive optical devices, resulting in ultra-low latency and cost-effective infrastructure.

Implementation Method 1

The power splitter operates as a passive device that is configured to replicate the spectrum of wavelengths and output a plurality of replicated spectrum of wavelengths. Each replicated spectrum of wavelengths of the plurality of replicated spectrum of wavelengths has a corresponding power that is a fraction of a total power received from the hub optical transceiver.

Methodology Applied
Scientific EffectOptical Power Splitting: Optical Fibre

Implementation Method 2

Each spoke transceiver is tunable to select a band of wavelengths that set a bandwidth for the each spoke transceiver.

Methodology Applied
Scientific EffectOptical Wavelength Selection: Optical Fibre

Data Source

PatentEP4320761B1Optimized switching fabric with multi-point optics in a data center
Publication Date: 2026.03.25 SONY INTERACTIVE ENTERTAINMENT LLC
  • EP4320761B1 patent drawingFigure 1
  • EP4320761B1 patent drawingFigure 2A
  • EP4320761B1 patent drawingFigure 2B

AI summary

An optical communication system including a hub optical transceiver, a power splitter, and a plurality of spoke transceivers. The hub optical transceiver is configured for receiving a spectrum of wavelengths. The power splitter is coupled to the hub optical transceiver, and operates as a passive device that is configured to replicate the spectrum of wavelengths and output a plurality of replicated spectrum of wavelengths, and each replicated spectrum of wavelengths has a corresponding power that is a fraction of a total power received from the hub optical transceiver. The plurality of spoke transceivers is coupled to the power splitter and each of the plurality of spoke transceivers is configured to receive a corresponding one of the plurality of replicated spectrum of wavelengths, wherein each spoke transceiver is tunable to select a band of wavelengths that set a bandwidth for the each spoke transceiver.