Hitless Multi-Carrier Spectrum Migration in Optical Transport

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Solution Overview

Problem

Existing optical transport network systems face challenges in efficiently migrating spectrums between multiple carrier groups, leading to service interruptions and suboptimal usage of optical spectrum resources due to fixed grid limitations, which cannot accommodate the growing demand for higher data rates and flexible service transmission.

Innovation Solution

A hitless multi-carrier spectrum migration method and apparatus that involves generating a secondary carrier, sending migration notifications, and migrating overhead information and services from a to-be-migrated carrier to a secondary carrier, ensuring that the resulting idle spectrum forms a consecutive idle spectrum area with sufficient width to meet new service requirements, utilizing a network management system and components like tunable lasers and modulators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If spectrum migration is performed between multiple carrier groups in conventional optical transport networks, then spectrum resources can be reallocated, but service interruptions occur during the migration process

Engineering Contradiction:
Improvespectrum resource reallocationVSAvoidservice continuity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-establishing a secondary carrier group before migrating services from the primary carrier group. The secondary carrier group is prepared in advance with all necessary overhead information and service data, so that when migration is triggered, the service can immediately switch to the pre-prepared secondary carrier without interruption. This resolves the contradiction by ensuring service continuity while enabling spectrum reallocation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses the secondary carrier group as an intermediary during the spectrum migration process. Instead of directly migrating services from the primary carrier group to a new spectrum location, the service is first copied to the secondary carrier group which acts as a buffer or mediator. This intermediary structure allows seamless switching and maintains service reliability while enabling flexible spectrum reallocation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If fixed 50 GHz optical spectrum grid slots are allocated to each optical carrier, then network management is simplified, but optical spectrum resources are wasted when carrier bandwidth is less than 50 GHz

Engineering Contradiction:
Improvenetwork management simplicityVSAvoidoptical spectrum resource waste
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent applies segmentation by dividing the optical spectrum into finer granularity slots of 12.5 GHz instead of the conventional 50 GHz grid. This allows optical carriers with smaller bandwidth requirements to occupy only the exact amount of spectrum they need, eliminating the waste that occurs when smaller carriers are forced into 50 GHz slots. The segmented approach maintains manageable network complexity while optimizing spectrum utilization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the fundamental parameter of optical spectrum grid slot width from 50 GHz to 12.5 GHz. This parameter change enables more precise matching between carrier bandwidth requirements and allocated spectrum resources, reducing optical spectrum waste while maintaining practical network management capabilities through the standardized finer grid structure.

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If optical spectrum grid slot width is reduced from 50 GHz to 12.5 GHz, then spectrum resource utilization improves, but device complexity increases due to multi-carrier coordination requirements

Engineering Contradiction:
Improveoptical spectrum resource efficiencyVSAvoidmulti-carrier coordination complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent reduces device complexity by performing preliminary actions during the setup phase. The secondary carrier group is pre-configured with all necessary overhead information, service data, and coordination parameters before migration. This upfront preparation eliminates the need for complex real-time coordination during spectrum migration operations, making the system more manageable despite the finer 12.5 GHz grid structure.

Inventive Principle:
Principle #10Preliminary action

4Adaptability or versatility

If services are migrated from primary carrier group to secondary carrier group, then spectrum resources are optimized, but overhead information and service data must be copied and synchronized

Engineering Contradiction:
Improvespectrum optimizationVSAvoidmigration preparation time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent minimizes migration preparation time by performing preliminary copying of overhead information and service data to the secondary carrier group in advance, during periods when the primary carrier group is actively serving traffic. This upfront preparation ensures that when migration is actually triggered, the data transfer and synchronization requirements are already satisfied, reducing the time loss associated with the migration process itself.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2983316B1Method and apparatus for multicarrier spectrum transition in service hitless mode
Publication Date: 2018.03.28 HUAWEI TECH CO LTD
  • EP2983316B1 patent drawingFigure 1~3
  • EP2983316B1 patent drawingFigure 4~5
  • EP2983316B1 patent drawingFigure 6

AI summary

A hitless multi-carrier spectrum migration method and apparatus are disclosed. The method includes: obtaining a spectrum of a secondary carrier and a to-be-migrated carrier in a target carrier group from a network management system, and generating the secondary carrier according to the spectrum of the secondary carrier; sending a migration notification to a peer network device, and performing answer response to the migration notification from the peer network device, where the answer response is used to determine that network devices at both ends can perform spectrum migration; sending migration signaling to the peer network device; and receiving the migration signaling sent by the peer network device, and migrating, according to the migration signaling, overhead information and a service that are borne on the to-be-migrated carrier in the target carrier group to the secondary carrier, where after the service that is borne on the to-be-migrated carrier is migrated to the secondary carrier, an idle spectrum corresponding to the to-be-migrated carrier and its adjacent idle spectrum can form a consecutive idle spectrum area. A spectral width requirement of a new service is met.