Optical Switch Node Dynamic Time Slot Allocation

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Solution Overview

Problem

Conventional optical network systems face limitations in the number of nodes that can be installed on a ring due to the number of wavelengths required, and static wavelength path allocation leads to inefficiencies in bandwidth usage and traffic accommodation, especially when traffic volumes fluctuate.

Innovation Solution

The optical network system dynamically allocates bandwidth based on traffic volume using WDM technique, allowing for increased node numbers without relying on the number of wavelengths, and employs a master node to synchronize and process time slots, preventing collisions at ring intersections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a wavelength path is statically set for each point to point in accordance with an estimated maximum traffic volume, then the network can handle peak traffic demands, but bandwidth utilization efficiency deteriorates when actual traffic volume is smaller than estimated

Engineering Contradiction:
Improvetraffic accommodation capabilityVSAvoidbandwidth utilization efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent implements dynamic bandwidth allocation by allowing nodes to flexibly use wavelength paths based on actual traffic demands rather than static pre-allocation. When traffic volume is small, nodes can share wavelength paths; when traffic volume increases, dedicated paths are established. This dynamic adjustment resolves the contradiction between ensuring peak traffic capacity and maintaining efficient bandwidth utilization during low-traffic periods.

Inventive Principle:
Principle #15Dynamics

2Productivity

If different wavelength paths with different wavelengths are set for each point to point, then traffic between specific points can be transmitted, but the number of nodes that can be installed on the ring is limited by the number of wavelengths

Engineering Contradiction:
Improvepoint to point communication capabilityVSAvoidnumber of wavelengths required
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent enables wavelength paths to serve multiple functions and multiple node pairs simultaneously. Instead of dedicating one wavelength path per point-to-point connection, a single wavelength path can be dynamically shared among multiple node pairs depending on traffic demands. This multi-functionality allows the network to support more nodes than the number of available wavelengths, resolving the limitation on node expansion.

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

Solution Approach 2:

The system dynamically allocates and deallocates wavelength paths based on real-time traffic demands between different node pairs. A wavelength path can be reassigned from one node pair to another as traffic patterns change, allowing the network to accommodate a larger number of nodes without requiring a proportional increase in the number of wavelengths.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If the number of wavelengths is increased to support more nodes, then more point to point connections can be established, but the system complexity and cost increase

Engineering Contradiction:
Improvenumber of supported nodesVSAvoidnumber of receivers required
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes receivers multi-functional by enabling them to monitor and respond to traffic demands from multiple node pairs. Instead of requiring a dedicated receiver at each node for every possible wavelength path, receivers can dynamically identify and process relevant traffic based on current network conditions, reducing the total number of receivers needed while supporting more nodes.

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

Data Source

PatentEP3264688B1Optical network system, optical switch node, master node, and node
Publication Date: 2021.08.18 NIPPON TELEGRAPH & TELEPHONE CORP
  • EP3264688B1 patent drawingFigure 1
  • EP3264688B1 patent drawingFigure 2
  • EP3264688B1 patent drawingFigure 3

AI summary

An optical network system includes a master node (101 A) and a plurality of optical switch nodes (101B to 101D), allowing the number of nodes without depending on the number of wavelengths. The master node (101A) is configured to: divide a wavelength path having an arbitrary wavelength into time slots each having a predetermined time period; and allocate the time slots to each of the optical switch nodes (101 B to 101 D). Each of the optical switch nodes (101B to 101D) is configured to: synchronize the time slots based on information delivered from the master node (101A); and thereby transmit or receive a data or performs route switching.