scholarly journals Invalid-Resource-Aware Spectrum Assignment for Advanced-Reservation Traffic in Elastic Optical Network

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4190
Author(s):  
Shufang He ◽  
Yang Qiu ◽  
Jing Xu
Keyword(s):  
Optical Networks ◽  
Optical Network ◽  
Resource Allocation Algorithm ◽  
Elastic Optical Network ◽  
Blocking Rate ◽  
Network Load ◽  
Resource Alignment ◽  
Routing And Spectrum Allocation ◽  
Resource Aware ◽  
The Postponement

Elastic optical networks (EONs) can make service accommodation more flexible and precise by employing efficient routing and spectrum allocation (RSA) algorithms. In order to improve the efficiency of RSA algorithms, the advanced-reservation technique was introduced into designing RSA algorithms. However, few of these advanced-reservation-based RSA algorithms were focused on the unavailable spectrum resources in EONs. In this paper, we propose an Advanced-Reservation-based Invalid-Spectrum-Aware (AR-ISA) resource allocation algorithm to improve the networking performance and the resource alignment of EONs. By employing a new index, Invalid Spectrum Rate (ISR), to record the proportion of unavailable spectrum resources in EONs, the proposed AR-ISA algorithm set a network load threshold to trigger the postponement of an arriving service. Compared with the traditional slack-based AR mechanism, the proposed algorithm has more concerns about the current spectrum usage of the path designated by the service than the conflicts between AR services and other existing services. To further increase the networking performance, the proposed algorithm adopts defragmentation to increase the number of available spectrum resources when postponing a service. Theoretical analysis and simulation results show that the proposed AR-ISA algorithm has obvious effectiveness in reducing the service blocking rate and increasing the spectrum alignment rate.

scholarly journals Investigation of dynamic routing and spectrum allocation methods in elastic optical networks

2017 ◽  
Vol 63 (1) ◽  
pp. 85-92 ◽  
Author(s):  
Edyta Biernacka ◽  
Jerzy Domżał ◽  
Robert Wójcik
Keyword(s):  
Optical Networks ◽  
Shortest Path ◽  
Optical Transmission ◽  
Optical Network ◽  
Simulation Software ◽  
Spectrum Allocation ◽  
Elastic Optical Network ◽  
Modulation Techniques ◽  
Routing And Spectrum Allocation ◽  
Allocation Methods

Abstract The introduction of flexible frequency grids and advanced modulation techniques to optical transmission, namely an elastic optical network, requires new routing and spectrum allocation techniques. In this paper, we investigate dynamic two-step routing and spectrum allocation (RSA) methods for elastic optical networks. K-shortest path-based methods as well as spectrum allocation methods are analysed and discussed. Experimental verification of the investigated techniques is provided using simulation software. Simulation results present effectiveness of routing and spectrum allocation methods for analyzed networks using requested bandwidth of connections. Moreover, performance of shortest path first methods improves considerably when a number of candidate paths increases in the UBN24 topology.

scholarly journals LBFA: A Load-Balanced and Fragmentation-Aware Resource Allocation Algorithm in Space-Division Multiplexing Elastic Optical Networks

Photonics ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 456
Author(s):  
Shengyu Zhang ◽  
Kwan Lawrence Yeung ◽  
Along Jin
Keyword(s):  
Optical Networks ◽  
Blocking Probability ◽  
Optical Network ◽  
Computation Method ◽  
Resource Allocation Algorithm ◽  
Space Division Multiplexing ◽  
Space Division ◽  
Critical Issues ◽  
Joint Load ◽  
Load Balanced

We consider a space-division multiplexing elastic optical network (SDM-EON) that supports super-channels (SChs). A Sch comprises a set of contiguous frequency slots on multiple cores in a multi-core fiber. The problem of finding a lightpath using SChs involves routing, modulation, spectrum and core assignment (RMSCA). To minimize the request blocking probability (RBP), two critical issues must be addressed. First, routing and modulation assignment (RMA) should not cause hotspots, or overutilized links. Second, spectrum and core assignment (SCA) should aim at minimizing fragmentation, or small frequency slot blocks that can hardly be utilized by future requests. In this paper, a pre-computation method is first proposed for better load balancing in RMA. Then an efficient fragmentation-aware SCA is proposed based on a new fragmentation metric that measures both the spectral and spatial fragmentation. With the enhanced RMA and SCA, a joint load-balanced and fragmentation-aware algorithm called LBFA is designed to solve the RMSCA problem. As compared with the existing algorithms, simulation results show that our LBFA provides significant reduction in RBP.

Research on CLIB Routing and Spectrum Allocation Algorithm in Elastic Optical Networks

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Li Li ◽  
Zhai Ya-Fang ◽  
Li Hong-Jie
Keyword(s):  
Optical Networks ◽  
Blocking Probability ◽  
Rapid Development ◽  
Optical Network ◽  
Spectrum Allocation ◽  
Mobile Internet ◽  
High Definition ◽  
Allocation Algorithm ◽  
High Bandwidth ◽  
Routing And Spectrum Allocation

AbstractWith the rapid development of mobile Internet, high-definition video and cloud computing, users’ bandwidth demands are not only larger and larger but also more and more diverse. To solve this problem, there searchers put forward the concept of elastic optical network (EON). EON adopts the transmission mode of elastic grid, which can allocate spectrum resources flexibly and meet high bandwidth and diversity requirements at the same time. Routing and spectrum allocation (RSA) is an important issue in EON. In this paper, we present a heuristic algorithm named constrained-lower-indexed-block (CLIB) allocation algorithm for the RSA problem. The algorithm is based on the K candidate paths. When there are available spectrum blocks on multiple candidate paths, if the increase of the path length does not exceed a given threshold, the lower index spectrum would be selected for the connection request on a longer path. The aim of the algorithm is to concentrate the occupied frequency slices on one side of the spectrum and leave another side of the spectrum to the later arrived connection requests as much as possible, to reduce the blocking probability of connection requests. Simulation results show that comparing with the first-last-fit and hybrid grouping algorithms, the CLIB algorithm can reduce the blocking probability of connection requests.

scholarly journals Performance Evaluation of Survivability Strategies for Elastic Optical Networks under Physical Layer Impairments

2017 ◽  
Vol 20 (2) ◽  
Author(s):  
Jurandir Lacerda Jr ◽  
Alexandre Fontinele ◽  
Igo Moura ◽  
André Soares
Keyword(s):  
Performance Evaluation ◽  
Optical Networks ◽  
Blocking Probability ◽  
Optical Network ◽  
Evaluation Study ◽  
Physical Layer ◽  
Elastic Optical Network ◽  
Physical Layer Impairments ◽  
A Performance

This paper carried out a performance evaluation study that compares two survivability strategies (DPP and SM-RSA) for elastic optical networks with and without physical layer impairments. The evaluated scenarios include three representative topologies for elastic optical network, NSFNET, EON and USA. It also analyzes the increase of blocking probability when the survivability strategies are evaluated under the realistic scenario that assumes physical layer impairments. For all studied topologies under physical layer impairments, the survivability strategies achieved blocking probability above 80%.

scholarly journals An Elastic Optical Network-based Architecture for the 5G Fronthaul

2018 ◽  
Author(s):  
Mateus Riva ◽  
Henrique Donâncio ◽  
Felipe R. Almeida ◽  
Gustavo B. Figueiredo ◽  
Rodrigo I. Tinini ◽  
...  
Keyword(s):  
Optical Networks ◽  
Optical Network ◽  
Access Network ◽  
Wait Time ◽  
Average Difference ◽  
5G Networks ◽  
Average Wait Time ◽  
Cloud Radio Access Network ◽  
Elastic Optical Network ◽  
Radio Access

In 5G networks, the traffic demands are expected to increase significantly. To deal with this problem, many research efforts focus on TWDMPON for the fronthaul. However, TWDM-PON suffers from the issue of wasted bandwidth when a demand is smaller than the channel. In order to avoid this inefficiency, we propose an OFDM-PON supported architecture for the Cloud Radio Access Network (C-RAN) topology to implement the technology of elastic optical networks into C-RAN. Experiments show that OFDM-PON allows for improved usage of the bandwidth (between 145% and 218% improvement), similar average wait time for requests (average difference below 7%), and similar request loss (average difference below 2%) in comparison to TWDM.

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