A Novel Spectrum Assignment Scheme for Time-Varying Traffic in Flexgrid Optical Networks

2018 ◽  
Vol 39 (3) ◽  
pp. 319-324
Author(s):  
Fengqing Liu ◽  
Yanfang Xu ◽  
Shilin Xiao
Keyword(s):  
Real Time ◽  
Optical Networks ◽  
Blocking Probability ◽  
Numerical Results ◽  
Time Varying ◽  
Spectrum Assignment ◽  
Assignment Scheme ◽  
Flexgrid Optical Networks ◽  
Over Time

Abstract In real-time communication, the bandwidth required by traffic may fluctuate over time, and the network should allocate spectrum flexibly to satisfy such demands. In this paper, a novel spectrum assignment scheme is proposed. It reduces the spectrum fragmentation by minimizing the number of spectrum-free windows and establishes a virtual sub-connection in a non-contiguous spectrum block for the incremental bandwidths of time-varying traffic, to eliminate the traffic relocation and interruption caused by traffic change. Numerical results demonstrate that the scheme proposed in this paper effectively reduces the network blocking probability, decreases the traffic interrupt ratio, and improves the performance of serving traffic.

scholarly journals Dynamic RSA Problem for Time-Varying Traffic in Spectrum Sliced Elastic Optical Path Network

2015 ◽  
Vol 61 (2) ◽  
pp. 179-184 ◽  
Author(s):  
Ireneusz Olszewski
Keyword(s):  
Optical Networks ◽  
Service Time ◽  
Bandwidth Allocation ◽  
Transmission Rate ◽  
Blocking Probability ◽  
Optical Path ◽  
Reference Frequency ◽  
Time Varying ◽  
Spectrum Assignment ◽  
Dynamic Bandwidth

Abstract Service time-varying traffic flexible optical networks require a dynamic bandwidth allocation in order to follow the source transmission rate. The problem of service time-varying traffic, assuming that the set of connection requests is not known in advance, is considered in this work. Connection requests arrive randomly and have random durations. The considered dynamic RSA problem involves minimizing the probability of future connections blocking while maintaining spectrum continuity constraints and non-overlapping spectrum assignment constraints between spectrum-adjacent connections on the network links. The proposed algorithm determines the path with the required number of slots around the reference frequency for a connection request. An analysis of the network with time-varying traffic on the network connections was carried out on the basis of spectrum expansion/contraction schemes which allow to determine average blocking probability of the additional slot requests on these connections. The obtained results have been compared with those obtained by a well known algorithm that solves the dynamic RSA problem.

scholarly journals Dynamic Routing and Spectrum Assignment based on the Availability of Consecutive Sub-channels in Flexible-grid Optical Networks

2021 ◽  
Author(s):  
Varsha Lohani
Keyword(s):  
Optical Networks ◽  
Orthogonal Frequency Division Multiplexing ◽  
Blocking Probability ◽  
Frequency Division ◽  
Recent Past ◽  
Spectrum Assignment ◽  
Rsa Algorithm ◽  
Adaptive Parameters ◽  
Routing And Spectrum Assignment ◽  
Flexible Grid

Variable bandwidth channels can be created in Flexible Grid Optical Networks using Optical Orthogonal Frequency Division Multiplexing (O-OFDM). This allows more efficient use of spectrum by allocating integral multiple of basic bandwidth slot to the lightpath requests. In these networks, the constraint of keeping all the allocated slots together is added when deciding the routes for the requests. This constraint is called the contiguity constraint, which makes the routing and spectrum arrangement algorithms more challenging. In any network, the lightpath requests will arrive and depart dynamically and invariably lead to spectrum fragmentation. Hence network will have to reduce the maximum possible utilization as well as increased blocking probability. In this paper, we have presented an improvised Routing and Spectrum Assignment (RSA) algorithm using consecutive spectrum slots that leads to lesser fragmentation. It is evident from the results that the presented RSA algorithm uses adaptive parameters to reduce the blocking probability and fragmentation compared to the other algorithms reported in the recent past.

Energy-Efficient Routing and Spectrum Assignment Algorithm with Physical-Layer Impairments Constraint in Flexible Optical Networks

2017 ◽  
Vol 38 (4) ◽  
Author(s):  
Jijun Zhao ◽  
Nawa Zhang ◽  
Danping Ren ◽  
Jinhua Hu
Keyword(s):  
Energy Efficiency ◽  
Optical Networks ◽  
Energy Efficient ◽  
Blocking Probability ◽  
Physical Layer ◽  
Energy Efficient Routing ◽  
Spectrum Assignment ◽  
Physical Layer Impairments ◽  
Routing And Spectrum Assignment ◽  
The Impact

AbstractThe recently proposed flexible optical network can provide more efficient accommodation of multiple data rates than the current wavelength-routed optical networks. Meanwhile, the energy efficiency has also been a hot topic because of the serious energy consumption problem. In this paper, the energy efficiency problem of flexible optical networks with physical-layer impairments constraint is studied. We propose a combined impairment-aware and energy-efficient routing and spectrum assignment (RSA) algorithm based on the link availability, in which the impact of power consumption minimization on signal quality is considered. By applying the proposed algorithm, the connection requests are established on a subset of network topology, reducing the number of transitions from sleep to active state. The simulation results demonstrate that our proposed algorithm can improve the energy efficiency and spectrum resources utilization with the acceptable blocking probability and average delay.

Elastic Spectrum Allocation for Time-Varying Traffic in FlexGrid Optical Networks

2013 ◽  
Vol 31 (1) ◽  
pp. 26-38 ◽  
Author(s):  
Miroslaw Klinkowski ◽  
Marc Ruiz ◽  
Luis Velasco ◽  
Davide Careglio ◽  
Victor Lopez ◽  
...  
Keyword(s):  
Optical Networks ◽  
Spectrum Allocation ◽  
Time Varying ◽  
Flexgrid Optical Networks

Evaluation of Network Blocking Probability and Network Utilization Efficiency on Proposed Elastic Optical Network using RSA Algorithms

2020 ◽  
Vol 41 (4) ◽  
pp. 403-409 ◽  
Author(s):  
Deepak Sharma ◽  
Suresh Kumar
Keyword(s):  
Optical Networks ◽  
Wavelength Division Multiplexing ◽  
Blocking Probability ◽  
Optical Network ◽  
Utilization Efficiency ◽  
Variable Load ◽  
Spectrum Assignment ◽  
Wavelength Division ◽  
Network Utilization ◽  
New Generation

AbstractElastic optical networks (EONs) are new generation optical networks that provide flexible bandwidth and spectrum assignment characteristics to accommodate diverse demand range over traditional dense wavelength division multiplexing (DWDM)-based networks. While overcoming spectrum contiguity and continuity constraints, Routing and Spectrum Assignment (RSA) is a challenging task in EONs. In this article, we have proposed an EON network model. Using existing RSA techniques we have analyzed the performance of the proposed model on the basis of Network Blocking Probability (NBP) and Network Utilization Efficiency (NUE) under variable load conditions. It has been found to be working optimally even at a load of 200 Erlangs.

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