Service Preemption Selection in Optical Networks

Solution Overview

Problem

In optical networks, service preemption leads to increased instability as existing services are dropped or rerouted due to bandwidth limitations, with intermediate network elements lacking visibility of service paths, resulting in suboptimal preemption decisions that affect multiple services.

Innovation Solution

A method for service preemption selection that includes receiving a request to establish a service while preempting existing ones, using a list of previously selected services and service selection criteria to minimize disruption, with a hierarchical approach considering common paths and service characteristics, and utilizing both distributed and hybrid control planes with Software Defined Networking (SDN) controllers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If intermediate network elements make preemption decisions based on local knowledge only, then the decision-making process is simple and fast, but the preemption decisions are suboptimal and affect multiple services unnecessarily

Engineering Contradiction:

Improvepreemption decision speedVSAvoidpreemption decision quality

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements preliminary action by having intermediate network elements forward preemption information along service paths before final preemption decisions are made. This allows nodes to prepare and propagate necessary information about existing services and their paths in advance, enabling more informed decisions without requiring complete network visibility at the moment of decision.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent employs feedback mechanisms where intermediate network elements provide information about existing services and their paths back to the originating network element. This feedback loop enables the originating element to make more accurate preemption decisions by considering the actual service path configurations and potential impact on other services.

Inventive Principle:

Principle #23Feedback

2Reliability

If the originating network element has complete knowledge of all service paths, then preemption decisions can be optimized, but the system complexity increases significantly

Engineering Contradiction:

Improvepreemption decision qualityVSAvoidnetwork visibility requirement

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the network visibility function into segments distributed across different network elements. Instead of requiring the originating element to have complete network-wide knowledge, each intermediate element maintains local knowledge and forwards relevant preemption information along service paths. This segmentation reduces the complexity burden on any single element while enabling optimized preemption decisions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses intermediate network elements as intermediaries that facilitate information flow between the originating element and the rest of the network. These intermediaries forward preemption information and service path details along service paths, enabling the originating element to make optimized decisions without directly maintaining complete network visibility.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If preemption is performed without considering service paths, then the preemption process is simple, but multiple services are affected causing increased network instability

Engineering Contradiction:

Improvepreemption process simplicityVSAvoidnetwork stability

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent implements preliminary action by having intermediate network elements forward preemption information along service paths before final preemption decisions are made. This allows nodes to prepare and propagate necessary information about existing services and their paths in advance, enabling more informed decisions without requiring complete network visibility at the moment of decision.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent employs feedback mechanisms where intermediate network elements provide information about existing services and their paths back to the originating network element. This feedback loop enables the originating element to make more accurate preemption decisions by considering the actual service path configurations and potential impact on other services.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10027762B2Service preemption selection systems and methods in networks

Publication Date: 2018.07.17 CIENA CORP

AI summary

Systems and methods for service preemption selection in a network include receiving, from an ingress link, a request to establish a service on a path in the network while preempting one or more existing services if required to establish the service, wherein the request comprises a list of any previously selected services for preemption and an indication of whether preemption is required on the ingress link, wherein the service and the one or more existing services comprise an end-to-end path in the network; selecting, if required based on the indication, one or more services for preemption on the ingress link based on service selection criteria; and forwarding the request on an egress link to an adjacent node with any updates based on the selecting.