End-to-End Redundancy and Maintenance Condition Design for Nationwide Optical Transport Network

Yoshihiko UEMATSU

IEICE TRANSACTIONS on Communications   Vol.E101-B    No.11    pp.2267-2276
Publication Date: 2018/11/01
Publicized: 2018/05/22
Online ISSN: 1745-1345
DOI: 10.1587/transcom.2017EBP3454
Type of Manuscript: PAPER
Category: Transmission Systems and Transmission Equipment for Communications
optical transport network,  availability,  redundancy,  maintenance condition,  resource pool,  failure-recovery time,  

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To achieve high end-to-end availability in nationwide optical transport network across thousands of office buildings, it is important to properly make each function redundant, and execute protection switching, repair failed functions and recover redundancy to prevent multiple simultaneous failures. High redundancy leads to high system cost and high power consumption, and tight conditions for recovery leads to high maintenance cost. Therefore it is important to optimize the balance between redundancy and maintenance condition based on appropriate availability indicators. We previously proposed a resource-pool control mechanism for a nationwide optical transport network that can optimize the balance. This paper proposes an end-to-end availability evaluation scheme for a nationwide optical transport network with our mechanism, by which network operators can design the pool-resource amount of each function and the maintenance conditions for each network area properly to satisfy the end-to-end availability requirement. Although the maintenance conditions are usually discussed based on failure-recovery times, they should be discussed based on cost- or load-based volumes for this design. This paper proposes a maintenance-operation-load evaluation scheme, which derives the required number of maintenance staff members from failure-recovery times. We also discuss the design of the pool-resource amount and maintenance conditions for each network area of a nationwide network based on the proposed evaluation schemes.