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A master's thesis from Aalborg University
Book cover


ExpectAll: A BDD Based Approach to Failure Resilience in Elastic Optical Networks

Term

4. term

Education

Publication year

2024

Submitted on

Pages

16

Abstract

With the increasing demand for higher bandwidth and quality of service in modern networks, how to achieve fast, resilient networks is an important field of research. Here, recent advances in elastic optical networks have enabled fine-grained resource allocation for traffic demands, which introduced the Routing and Spectrum Allocation (RSA) problem. State-of- the-art methods for finding optimal solutions to the RSA problem are too slow for real-time practical applications, such as ensuring failure resilience, and faster methods cannot guarantee optimal resource allocation. Moreover, current methods for ensuring failure resilience in classic networking cannot be directly adapted to optical networks, and current methods for optical networks generally rely on over allocation of the spectrum to ensure rapid recovery. To this end, we present the tool ExpectAll, a novel approach based on binary decision diagrams (BDDs) to ensure failure resilience for multi-link failures without resorting to spectrum overallocation. Our method efficiently computes solutions to the RSA problem, facilitating optimal failover solutions for any failure scenario involving up to k links. ExpectAll surpasses state-of-the- art methods in both the speed of finding a single optimal solution during a failure and the preparation time required to compute sufficient solutions to ensure resilience for arbitrary large k-link failures. Additionally, since ExpectAll can compute and represent all potential solutions, it is adaptable for network operators to find solutions that meet specific desired properties.