Recent research progress on spectrum management approaches in software-defined elastic optical networks

Hop distance–based bandwidth allocation technique for elastic optical networks

“…The main focus of routing and spectrum allocation assignment (RSA) EON algorithms is that connections must satisfy both the continuity and frequency contiguity constraints …”

“…Each mask comprises of two numbers that represent the range of FS available to the n-hop connection. For example, if the minimum hop distance for a connection is 3, then the mask mask [3] = [0, 100] has the meaning that only FSs with index from 0 to 100 can used.…”

“…The main focus of routing and spectrum allocation assignment (RSA) EON algorithms is that connections must satisfy both the continuity and frequency contiguity constraints. 2,3 Our work addresses the fairness problem that multihop connections face, specifically that connections comprising many hops suffer from a larger BP compared to those over fewer hops, as satisfying the continuity and contiguity constraint over longer distances becomes increasingly harder. Thus, we propose a new metric in this paper, the normalized to hop-distance bandwidth blocking probability (normalized_BBP) that considers connection hop distance and its effect on network performance.…”

A Performance Comparison of Centralized and Distributed Spectrum Management Techniques in Elastic Optical Networks

“…EONs have been extensively studied over the past decade [22,[24][25][26][27][28][29][30][31][32] from various perspectives [24], from early architectural assessments establishing the potential advantages of EONs over fixed-grid WDM [25] to specific resource allocation studies that aim to provide efficient routing and spectrum allocation algorithms [24,26,27] or solutions to the spectrum fragmentation problem in EONs [29]. References [25,26] cover key aspects of EON or SLICE, i.e., the rules of frequency allocation, reservation mechanism, and routing and spectrum allocation algorithms.…”

“…Generalized Multiprotocol Label Switching (GMPLS) based signaling protocols and their extensions are commonly utilized for this purpose [5,6,11,14] following the well-established practice of separating the control-plane and the data-plane in WDM optical networks [18][19][20]. It is noted that despite the recent interest in applying a Software Defined Networking (SDN) paradigm (e.g., OpenFLow protocols) in optical networks [21,22] some researchers envision that a traditional embedded control-plane based on GMPLS will continue to be in place even in optical networks that utilize SDN due to factors and performance requirements specific to optical networks [23]. These factors include vendor proprietary frame formats, different granularity of grooming functions, proprietary modulation/encoding and Forward Error Correcting (FEC) schemes, and stringent recovery time constraints [23].…”