Spectrum Efficient Super-Channels in Dynamic Flexible Grid Networks – A Blocking Analysis

Thiagarajan, Sashisekaran; Frankel, M.Y.; Boertjes, David

doi:10.1364/ofc.2011.otui6

Cited by 26 publications

(9 citation statements)

References 4 publications

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“…A similar idea has been presented in [13] as inverse multiplexing. In this paper, the authors split high bit-rate demands into a bunch of lower bit-rate connections, each one of equal bandwidth, assigning the spectrum of these new connections in a Shortest-Path (SP) First-Fit (FF) basis to avoid contention situations.…”

Section: Proposed Mechanismmentioning

confidence: 90%

Lightpath fragmentation for efficient spectrum utilization in dynamic elastic optical networks

Pages

Perelló

Spadaro

2012

2012 16th International Conference on Optical Network Design and Modelling (ONDM)

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Abstract-The spectrum-sliced elastic optical path network (SLICE) architecture has been presented as an efficient solution for flexible bandwidth allocation in optical networks. An homologous problem to the classical Routing and Wavelength Assignment (RWA) arises in such an architecture, called Routing and Spectrum Assignment (RSA). Imposed by current transmission technologies enabling the elastic optical network concept, the spectrum contiguity constraint must be ensured in the RSA problem, meaning that the bandwidth requested by any connection must be allocated over a contiguous portion of the spectrum along the path between source and destination nodes. In a dynamic network scenario, where incoming connections are established and disconnected in a quite random fashion, spectral resources tend to be highly fragmented, preventing the allocation of large contiguous spectrum portions for high datarate connection requests. As a result, high data-rate connections experience unfairly increased bocking probability in contrast to low data-rate ones. In view of this, the present article proposes a lightpath fragmentation mechanism that makes use of the idle transponders in the source node of a high data-rate connection request to fragment it into multiple low data-rate ones, more easily allocable in the network. Besides, aiming to support such an operation, a light-weight RSA algorithm is also proposed so as to properly allocate the generated lightpath fragments over the spectrum. Benefits of the proposed approach are quantified through extensive simulations, showing drastically reduced high data-rate connection blocking probability compared to a usual contiguous bandwidth allocation, while keeping the performance of low data-rate requests to similar levels.

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Section: Proposed Mechanismmentioning

confidence: 90%

Lightpath fragmentation for efficient spectrum utilization in dynamic elastic optical networks

Pages

Perelló

Spadaro

2012

2012 16th International Conference on Optical Network Design and Modelling (ONDM)

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“…Solutions for the two-step approach are, basically, classified in fixed shortest-path routing [4], [5], [6] and alternative path routing [7], [8], [9]. The first class of algorithms calculates a shortest path for all pairs of nodes and applies some spectrum assignment policy to the shortest path.…”

Section: Related Workmentioning

confidence: 99%

“…The second class of algorithms calculates a set of potential paths among all pairs of nodes, chooses one of the paths and applies some spectrum assignment policy. For both classes of algorithms the first-fit spectrum assignment policy is most used [5], [6], [9]. Some works propose different policies such as most-used spectrum assignment policy [8] and the maximization of the common large segment policy [7].…”

Section: Related Workmentioning

confidence: 99%

“…In the first one, the paths Algorithm 1: Alternative Routing and Zone-Based Spectrum Assignment Algorithm 1 Compute a set of k-shortest paths P (s,d) in the network topology for each pair of nodes (s, d) 2 Divide the spectrum into a set of zones Z with a zone z ∈ Z for each type of connection c ∈ C 3 foreach online connection request r = (s, d, c) do 4 Rank the zones z ∈ Z in a priority queue Z c for each type of connection c ∈ C 5 while Z c = ∅ do 6 Pop zone z from priority queue Z c 7 Rank the paths p ∈ P (s,d) in a priority queue P z 8 while P z = ∅ do 9 Pop path p from priority queue P z 10 if ∃c continuous and contiguous slots available in zone z for path p then 11 if zone z is the preferential zone for r then 12 Accept connection r using path p and the first c−slots available in zone z p ∈ P (s,d) are ranked in increasing order of the number of hops of p. In the second one, the paths p ∈ P (s,d) are ranked in decreasing order of the residual capacity into candidate zone z. The residual capacity of path p for zone z is given by the sum of the slots in zone z that are available in all hops of the path p.…”

Section: Dynamic Routing and Spectrum Assignmentmentioning

confidence: 99%

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Alternative routing and zone-based spectrum assignment algorithm for flexgrid optical networks

Scaraficci

Fonseca

2014

2014 IEEE International Conference on Communications (ICC)

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In optical flexgrid networks, the optical spectrum can be allocated at a much finer granularity than it can be in fixed-grid WDM networks and variable spectrum widths can be assigned to the lightpaths according to the transmission rates, leading to more efficient spectrum usage. However, the dynamic establishment and tear down of lightpaths yields to the fragmentation of the spectrum with increase in blocking of connections, mainly connections demanding large spectrum widths. This paper proposes a novel algorithm that introduces a zone-based assignment policy together with an alternative path routing mechanism based on the maximum capacity available. Results derived via simulation using different topologies and considering connections requests from 40Gbps to 1000Gbps, show that the proposed algorithm leads to blocking ratio consistently lower than those given by traditional approaches. It also reduces the blocking ratio of high rates connections, in some cases, by a factor of six.

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“…75 GHz for 400 Gb/s and 150 GHz for 1 Tb/s. Hence, there has been growing interest in gridless and elastic optical networking [5,6] as a means to efficiently accommodate a mix of superchannels and low-speed channels as well as to improve point-to-point and overall network efficiency, e.g. 400G occupying 75-GHz bandwidth is more than twice as efficient as 100G using 50 GHz.…”

Section: Introductionmentioning

confidence: 99%

Field trial of a 15 Tb/s adaptive and gridless OXC supporting elastic 1000-fold all-optical bandwidth granularity

Amaya¹,

Zervas²,

Rofoee³

et al. 2011

Opt. Express

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An adaptive gridless OXC is implemented using a 3D-MEMS optical backplane plus optical modules (sub-systems) that provide elastic spectrum and time switching functionality. The OXC adapts its architecture on demand to fulfill the switching requirements of incoming traffic. The system is implemented in a seven-node network linked by installed fiber and is shown to provide suitable architectures on demand for three scenarios with increasing traffic and switching complexity. In the most complex scenario, signals of mixed bit-rates and modulation formats are successfully switched with flexible per-channel allocation of spectrum, time and space, achieving over 1000-fold bandwidth granularity and 1.5 Tb/s throughput with good end-to-end performance.

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Spectrum Efficient Super-Channels in Dynamic Flexible Grid Networks – A Blocking Analysis

Cited by 26 publications

References 4 publications

Lightpath fragmentation for efficient spectrum utilization in dynamic elastic optical networks

Lightpath fragmentation for efficient spectrum utilization in dynamic elastic optical networks

Alternative routing and zone-based spectrum assignment algorithm for flexgrid optical networks

Field trial of a 15 Tb/s adaptive and gridless OXC supporting elastic 1000-fold all-optical bandwidth granularity

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