Spectrum management techniques for elastic optical networks: A survey

Spectrum Assignment in Mesh Elastic Optical Networks

“…Second, it is quite difficult to characterize the performance of heuristic algorithms, and our recent work has demonstrated that heuristics for the related RWA problem produce solutions that are far away from optimal even for problem instances of moderate size [19]. For a survey of spectrum management techniques in elastic optical networks, including a review of solution approaches to RSA problem variants, we refer the reader to our recent survey [20].…”

Class-based first-fit spectrum allocation with fragmentation avoidance for dynamic flexgrid optical networks

“…Similar to fragmentation in hard disk drives, once new connections are added and existing connections are terminated, the free spectrum eventually becomes interspersed (or scattered). Horizontal fragmentation refers to a scenario where a spectral block may not be available on all links of a path for a request although individual links may have sufficient bandwidth [15], [16]. On the other hand, vertical fragmentation arises when the idle spectral resources on individual links turn out to be scattered making it hard to find large contiguous spectral blocks to be allocated to large demands [15].…”

“…Reactive defragmentation policies are triggered once the spectrum becomes heavily fragmented [17], [18], [19]. On the other hand, proactive fragmentation avoidance has the advantage over reactive defragmentation schemes that it does not require reconfiguration of existing connections which may cause disruption for live connections [16]. The focus of this paper is on proactive fragmentation avoidance.…”

“…A spectrum-consecutiveness-based spectrum allocation policy with increased computational complexity is proposed in [22] which is shown to reduce blocking probabilities compared to FF. For other proposed spectrum allocation policies in the context of dynamic flexgrid optical networks, we refer the reader to [16], [17], [20].…”

Spectrum Continuity and Contiguity based Dedicated Protection for Flexible Optical Networks

“…The SCCDP pseudocode is presented in Algorithm 1. It applies some steps proposed by Suurballe et al [14] to find a link-disjoint route pair and to deal with the trap topology problem (lines [5][6][7][8][9]. SCCDP algorithm determines a route P1 with spectrum continuity and contiguity using the SCSP routing algorithm in T (line 2).…”