scholarly journals Statistical Assessment of Open Optical Networks

Photonics ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 64 ◽  
Author(s):  
Emanuele Virgillito ◽  
Alessio Ferrari ◽  
Andrea D’Amico ◽  
Vittorio Curri

In order to cope with the increase of the final user traffic, operators and vendors are pushing towards physical layer aware networking as a way to maximize the network capacity. To this aim, optical networks are becoming more and more open by exposing physical parameters enabling fast and reliable estimation of the lightpath quality of transmission. This comes in handy not only from the point of view of the planning and managing of the optical paths but also on a more general picture of the whole optical network performance. In this work, the Statistical Network Assessment Process (SNAP) is presented. SNAP is an algorithm allowing for estimating different network metrics such as blocking probability or link saturation, by generating traffic requests on a graph abstraction of the physical layer. Being aware of the physical layer parameters and transceiver technologies enables assessing their impact on high level network figures of merit. Together with a detailed description of the algorithm, we present a comprehensive review of several results on the networking impact of multirate transceivers, flex-grid spectral allocation as a means to finely exploit lightpath capacity and of different Space Division Multiplexing (SDM) solutions.

2017 ◽  
Vol 20 (2) ◽  
Author(s):  
Jurandir Lacerda Jr ◽  
Alexandre Fontinele ◽  
Igo Moura ◽  
André Soares

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%.


2020 ◽  
Vol 8 (5) ◽  
pp. 4245-4249

In the last few years, internet traffic increases continuously due to the more use of live streaming and social sites. To accommodate such high traffic demand the more bandwidth is required. The elastic optical network (EON) is a promising solution for the capacity expansion that can meet the future bandwidth requirement. The EON can provide a higher bit rate. In this paper we purposed a recovery strategy for failure in EON. Our purposed strategy shows the more acceptance rate for randomly generated source (s)-destination (d) requests. Here we considered two topologies viz. COST239 and NSFNET. Then evaluate their performance for Recovery Time, bandwidth blocking probability (BBP) and network capacity utilization (NCU), in which our purposed scheme provides lesser BBP and lower NCU for both topologies and low recovery time than shared path protection (SPP and dedicated path protection (DPP).


2021 ◽  
Vol 2 (3) ◽  
pp. 24-26
Author(s):  
Lina Cheng

Dynamic allocation request and spectrum release will lead to spectrum fragmentation, which will affect the allocation of subsequent services and spectrum resource utilization of elastic optical network. This paper proposes a new routing and spectrum allocation algorithm based on deep learning, which will find the best routing and spectrum allocation method for a specific network, so as to improve the overall network performance. Simulation results show that compared with the traditional resource allocation strategy, the neural network model used in this paper can improve the degree of spectrum fragmentation and reduce the network blocking probability.


Photonics ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 456
Author(s):  
Shengyu Zhang ◽  
Kwan Lawrence Yeung ◽  
Along Jin

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.


2013 ◽  
Vol 9 (2) ◽  
pp. 1055-1062
Author(s):  
Ifrah Amin ◽  
Gulzar Ahmad dar ◽  
Hrdeep singh Saini

Routing and wavelength assignment problem is one of the main problem in optical networks. The foremost problem is the routing problem after which the wavelength assignment is to be decided. In this paper we have proposed a routing strategy for optimization of the performance of the optical network in terms of blocking probability. The strategy proposed is better than the conventional algorithm in terms of blocking. 


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Sridhar Iyer

AbstractIn this article, we focus on the optimization of lightpath routing in an online Space Division Multiplexing-based Elastic Optical Network (SDM-b-EON) which is protected by the dedicated route protection (DRP) strategy. In view of the aforementioned, the Online Protection and Routing Algorithm with Regeneration (OPaRAwR) method is proposed which (i) protects the lightpaths through DRP, (ii) accounts for the presence of transceivers in the network, and (iii) ensures the routing of translucent lightpaths through the spectral super-channels over the spatial modes links. In regard to regeneration, we investigate two scenarios which differ in their regeneration variability level in addition to the adjustment of modulation formats (MFs) as per the transmission route characteristics. Extensive simulation experiments are conducted considering realistic transmission reach values and two realistic network topologies. The obtained simulation results demonstrate that the proposed OPaRAwR method significantly outperforms various reference techniques in terms of bandwidth blocking probability (BwBP). In addition, the results also show that significant benefits can be obtained in regard to the utilization of resources (spectrum and transceivers) with much lesser BwBP when the regeneration is conducted with complete flexibility and MF conversion is also permitted at every node of the SDM-b-EON.


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Li Li ◽  
Zhai Ya-Fang ◽  
Li Hong-Jie

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.


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Sridhar Iyer

AbstractIn the current work, we focus on the optimization of lightpath routing in a Space Division Multiplexing based Elastic Optical Network (SDM-b-EON) for which we propose an online routing algorithm, named as Resource Efficient Online Routing Algorithm with Regeneration (REORAwR) which, in addition to ensuring the routing of translucent lightpaths through spectral super-channels over spatial modes links also accounts for the presence of the transceivers in the network. The proposed REORAwR algorithm is tunable such that it can either aim to reduce the bandwidth blocking probability or can aim to minimize the overall consumed power. In regard to regeneration, we investigate two scenarios which differ in their regeneration variability level in addition to the adjustment of modulation formats as per the transmission route characteristics. We conduct extensive simulations considering two realistic network topologies and realistic transmission reach values. The obtained results demonstrate that significant benefits can be obtained in regard to the utilization of both the major network resources (spectrum and transceivers) when regeneration is conducted with complete flexibility and modulation format conversion is also permitted at every node of the SDM-b-EON. In addition, the obtained results also show that when compared to spectrum usage, in terms of the overall consumed power, the performance profits which can be obtained in a translucent SDM-b-EON are very small.


2019 ◽  
Vol 9 (3) ◽  
pp. 399 ◽  
Author(s):  
Stanisław Kozdrowski ◽  
Mateusz Żotkiewicz ◽  
Sławomir Sujecki

New generation of optical nodes in dense wavelength division multiplexed networks enables operators to improve service flexibility and make significant savings, both in operational and capital expenditures. Thus the main objective of the study is to minimize optical node resources, such as transponders, multiplexers and wavelength selective switches, needed to provide and maintain high quality dense wavelength division multiplexed network services using new generation of optical nodes. A model based on integer programming is proposed, which includes a detailed description of an optical network node. The impact on the network performance of conventional reconfigurable optical add drop multiplexer technology is compared with colorless, directionless and contentionless approaches. The main focus of the presented study is the analysis of the network congestion problem arising in the context of both reconfigurable optical add drop multiplexer technologies. The analysis is supported by results of numerical experiments carried out for realistic networks of different dimensions and traffic demand sets.


Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 2021
Author(s):  
Ammar Armghan

The evolution journey of optical network (ON) towards heterogeneous and flexible frameworks with high order of applications is continued from the last decade. Furthermore, the prominence of optical security, amount of transmitted data, bandwidth, and dependable presentation are heightened. The performance of ON is degraded in view of various natures of attacks at the physical layer, such as service disrupting and access to carrier data. In order to deal with such security breaches, new and efficient ON must be identified. So, this paper elaborates a detailed structure on physical layer security for heterogeneous ON. Possible mechanisms, such as Elliptic-curve Diffie–Hellman (ECDH), are used to treat a physical layer attack, and an efficient framework is proposed in this paper for 64 quadrature amplitude modulation-based orthogonal frequency division multiplex (64QAM-OFDM) ONs. Finally, theoretical and simulation validations are presented, and the effective results of the proposed method and viewpoint are concluded.


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