Analytical models of blocking probability for multi-granularity cross-connect-based optical networks

2009 ◽  
Vol 3 (11) ◽  
pp. 1716 ◽  
Author(s):  
Y. Zhao ◽  
J. Zhang ◽  
D. Han ◽  
X. Zhang ◽  
Y. Yao ◽  
...  
Keyword(s):  
Optical Networks ◽  
Blocking Probability ◽  
Analytical Models ◽  
Cross Connect

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.

scholarly journals Blocking Probability in Pipeline Forwarding Networks

2014 ◽  
Vol 10 (1) ◽  
pp. 30
Author(s):  
Mario Baldi ◽  
Andrea Vesco
Keyword(s):  
Proper Time ◽  
Blocking Probability ◽  
Network Routing ◽  
Analytical Models ◽  
Network Resources ◽  
High Resource ◽  
Delay Sensitive ◽  
Network Utilization ◽  
Real Size ◽  
Time Frames

As multimedia communications continue to grow steadily on the Internet, pipeline forwarding (PF) of packets provides a scalable solution for engineering delay-sensitive traffic while guaranteeing deterministic Quality of Service (QoS) with high resource utilization. In PF networks resource reservation, while ensuring deterministic QoS on a per-flow basis, can result in a not null blocking probability. A reservation request may fails due to enough resources being available but not during the proper time frames. This work analyses blocking probability of reservation requests since it affects the capability of utilizing network resources to carry traffic with deterministic QoS. The blocking probability and, consequently, the achievable network utilization are analytically derived on general topology PF networks as function of the traffic intensity given the traffic matrix and the network routing. The correctness of the blocking models is also assessed by simulation in different scenarios. This work represent a valuable contribution over previous analytical models of the blocking probability as their application to real size scenarios is impractical due to their computation complexity.

scholarly journals Exploring Analytical Models for Performability Evaluation of Virtualized Servers using Dynamic Resource

2019 ◽  
Vol 14 (5) ◽  
pp. 647
Author(s):  
Yonal Kirsal
Keyword(s):  
Resource Utilization ◽  
Blocking Probability ◽  
Spectral Expansion ◽  
Form Solution ◽  
Analytical Models ◽  
Mean Response Time ◽  
Proposed Model ◽  
Dynamic Resource ◽  
Mean Queue Length ◽  
Markov Reward

Virtualization of resources is a widely accepted technique to optimize resources in recent technologies. Virtualization allows users to execute their services on the same physical machine, keeping these services isolated from each other. This paper proposes the analytical models for performability evaluation of virtualized servers with dynamic resource utilization. The performance and avalability models are considered separately due to the behaviour of the proposed system. The well-known Markov Reward Model (MRM) is used for the solution of the analytical model considered together with an exact spectral expansion and product form solution. The dynamic resource utilization is employed to enhance the QoS of the proposed model which is another major issue in the performance characterization of virtulazilation. In this paper, the performability output parameters, such as mean queue length, mean response time and blocking probability are computed and presented for the proposed model. In addition, the performability results obtained from the analytical models are validated by the simulation (DES) results to show the accuracy and effectiveness of the proposed work. The results indicate the proposed modelling results show good agreement with DES and understand the factors are very important to improve the QoS.

scholarly journals Routing Strategies in Survivable Optical Networks

2013 ◽  
Vol 9 (2) ◽  
pp. 1055-1062
Author(s):  
Ifrah Amin ◽  
Gulzar Ahmad dar ◽  
Hrdeep singh Saini
Keyword(s):  
Optical Networks ◽  
Blocking Probability ◽  
Optical Network ◽  
Routing And Wavelength Assignment ◽  
Wavelength Assignment ◽  
Routing Problem ◽  
Routing Strategy ◽  
Survivable Optical Networks ◽  
Conventional Algorithm ◽  
Better Than

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. 

Blocking probability analysis model for flexible spectrum optical networks

2014 ◽  
Vol 12 (7) ◽  
pp. 070601-70606 ◽  
Author(s):  
Yongli Zhao Yongli Zhao ◽  
Jie Zhang Jie Zhang
Keyword(s):  
Optical Networks ◽  
Blocking Probability ◽  
Probability Analysis ◽  
Analysis Model

On the Performance of Protected and Online Routing Enabled Translucent Space Division Multiplexing-Based Elastic Optical Networks

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Sridhar Iyer
Keyword(s):  
Optical Networks ◽  
Blocking Probability ◽  
Optical Network ◽  
Routing Algorithm ◽  
Modulation Formats ◽  
Space Division Multiplexing ◽  
Space Division ◽  
Spatial Modes ◽  
Variability Level ◽  
Network Topologies

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.

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.

Resource Efficient Online Routing Enabled Translucent Space Division Multiplexing Based Elastic Optical Networks

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Sridhar Iyer
Keyword(s):  
Optical Networks ◽  
Blocking Probability ◽  
Optical Network ◽  
Routing Algorithm ◽  
Network Resources ◽  
Modulation Formats ◽  
Modulation Format ◽  
Online Routing ◽  
Space Division Multiplexing ◽  
Space Division

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.

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