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Planning and Provisioning Strategies for Optical Core Networks
Linköping University, Department of Electrical Engineering, Information Coding. Linköping University, The Institute of Technology.
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Optical communication networks are considered the main catalyst for the transformation of communication technology, and serve as the backbone of today's Internet. The inclusion of exciting technologies, such as, optical amplifiers, wavelength division multiplexing (WDM), and reconfigurable optical add/drop multiplexers (ROADM) in optical networks have made the cost of information transmission around the world negligible. However, to maintain the cost effectiveness for the growing bandwidth demand, facilitate faster provisioning, and provide richer sets of service functionality, optical networks must continue to evolve. With the proliferation of cloud computing the demand for a promptly responsive network has increased. Moreover, there are several applications, such as, real time multimedia services that can become realizable, depending on the achievable connection set-up time.

Given the high bandwidth requirements and strict service level specifications (SLSs) of such applications, dynamic on-demand WDM networks are advocated as a first step in this evolution. SLSs are metrics of a service level agreement (SLA), which is a contract between a customer and network operator. Apart from the other candidate parameters, the set-up delay tolerance, and connection holding-time have been defined as metrics of SLA. Exploiting these SLA parameters for on-line provisioning strategies exhibits a good potential in improving the overall network blocking performance. However, in a scenario where connection requests are grouped in different service classes, the provisioning success rate might be unbalanced towards those connection requests with less stringent requirements, i.e., not all the connection requests are treated in a fair way.

The first part of this thesis focuses on different scheduling strategies for promoting the requests belonging to smaller set-up delay tolerance service classes. The first part also addresses the problem of how to guarantee the signal quality and the fair provisioning of different service classes, where each class corresponds to a specified target of quality of transmission. Furthermore, for delay impatient applications the thesis proposes a provisioning approach, which employs the possibility to tolerate a slight degradation in quality of transmission during a small fraction of the holding-time.

The next essential phase for scaling system capacity and satisfying the diverse customer demands is the introduction of flexibility in the underlying technology. In this context, the new optical transport networks, namely elastic optical networks (EON) are considered as a worthwhile solution to efficiently utilize the available spectrum resources. Similarly, space division multiplexing (SDM) is envisaged as a promising technology for the capacity expansion of future networks. Among the alternative for flexible nodes, the architecture on demand (AoD) node has the capability to dynamically adapt its composition according to the switching and processing needs of the network traffic.

The second part of this thesis investigates the benefits of set-up delay tolerance for EON by proposing an optimization model for dynamic and concurrent connection provisioning. Furthermore, it also examines the planning aspect for flexible networks by presenting strategies that employ the adaptability inherent in AoD. Significant reduction in switching devices is attainable by proper planning schemes that synthesized the network by allocating switching device where and when needed while maximizing fiber switching operation. In addition, such a design approach also reduces the power consumption of the network. However, cost-efficient techniques in dynamic networks can deteriorate the network blocking probability owing to insufficient number of switching modules. For dynamic networks, the thesis proposes an effective synthesis provisioning scheme along with a technique for optimal placement of switching devices in the network nodes.

The network planning problem is further extended to multi-core-fiber (MCF) based SDM networks. The proposed strategies for SDM networks aim to establish the connections through proper allocation of spectrum and core while efficiently utilizing the spectrum resources. Finally, the optimal planning strategy for SDM networks is tailored to fit synthetic AoD based networks with the goal to optimally build each node and synthesize the whole network with minimum possible switching resources.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2015. , 84 p.
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1645
National Category
Information Systems Computer and Information Science
Identifiers
URN: urn:nbn:se:liu:diva-115908DOI: 10.3384/diss.diva-115908ISBN: 978-91-7519-115-7 (print)OAI: oai:DiVA.org:liu-115908DiVA: diva2:797310
Public defence
2015-04-30, Signalen, Hus B, Campus Valla, Linköping, 10:15 (English)
Opponent
Supervisors
Available from: 2015-03-23 Created: 2015-03-23 Last updated: 2015-03-26Bibliographically approved
List of papers
1. Service Differentiated Provisioning in Dynamic WDM Networks Based on Set-Up Delay Tolerance
Open this publication in new window or tab >>Service Differentiated Provisioning in Dynamic WDM Networks Based on Set-Up Delay Tolerance
2013 (English)In: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 5, no 11, 1250-1261 p.Article in journal (Refereed) Published
Abstract [en]

Optical networks are expected to provide a unified platform for a diverse set of emerging applications (three-dimensional TV, digital cinema, e-health, grid computing, etc). The service differentiation will be an essential feature of these networks. Considering the fact that users have different levels of patience for different network applications, referred to as set-up delay tolerance, it will be one of the key parameters for service differentiation. Service differentiation based on set-up delay tolerance will not only enable network users to select an appropriate service class (SC) in compliance with their requirements, but will also provide an opportunity to optimize the network resource provisioning by exploiting this information, resulting in an improvement in the overall performance. Improvement in network performance can be further enhanced by exploiting the connection holding-time awareness. However, when multiple classes of service with different set-up delay tolerances are competing for network resources, the connection requests belonging to SCs with higher set-up delay tolerance have better chances to grab the resources and leave less room for the others, resulting in degradation in the blocking performance of less patient customers. This study proposes different scheduling strategies for promoting the requests belonging to smaller set-up delay tolerance SCs, such as giving priority, reserving some fraction of available resources, and augmenting the research space by providing some extra paths. Extensive simulation results show that 1) priority in the rescheduling queue is not always sufficient for eradicating the degradation effect of high delay tolerant SCs on the provisioning rate of the most stringent SC, and 2) by utilizing the proposed strategies, resource efficiency and overall network blocking performance improve significantly in all SCs.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2013
Keyword
Connections holding-time; Deadline driven provisioning; Dynamic connection provisioning; Dynamic scheduling; Set-up delay tolerance; WDM networks
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-103306 (URN)10.1364/JOCN.5.001250 (DOI)000328643500013 ()
Available from: 2014-01-17 Created: 2014-01-16 Last updated: 2017-12-06
2. Fair Scheduling of Dynamically Provisioned WDM Connections with Differentiated Signal Quality
Open this publication in new window or tab >>Fair Scheduling of Dynamically Provisioned WDM Connections with Differentiated Signal Quality
2012 (English)In: Proceedings of the 16th International Conference on Optical Network Design and Modeling (ONDM), 2012, IEEE , 2012, 1-6 p.Conference paper, Published paper (Refereed)
Abstract [en]

Emerging, on-demand applications (e.g., Interactive video, ultra-high definition TV, backup storage and grid computing) are gaining momentum and are becoming increasingly important. Given the high bandwidth required by these applications, Wavelength Division Multiplexing (WDM) networks are seen as the natural choice for their transport technology. Among the various on-line strategies proposed to provision such services, the ones based on service level agreement (SLA) metrics such as setup delay tolerance and connection holding-time awareness showed a good potential in improving the overall network blocking performance. However, in a scenario where connection requests are grouped in different service classes, the provisioning success rate might be unbalanced towards those connection requests with less stringent requirements, i.e., not all the connection requests are treated in a fair way. This paper addresses the problem of how to guarantee the signal quality and the fair provisioning of different service classes, where each class corresponds to a specified target of quality of transmission (QoT). With this objective in mind three fair scheduling algorithms are proposed in a dynamic traffic scenario, each one combining in a different way the concept of both set-up delay tolerance and connection holding-time awareness. Proposed solutions are specifically taylored to facilitate the provisioning of the most stringent service class so as to balance the success rate among the different classes. Simulation results confirm that the proposed approaches are able to guarantee a fair treatment reaching up to 99% in terms of Jain's fairness index, considering the per-class success ratio, without compromising the improvements in terms of overall network blocking probability.

Place, publisher, year, edition, pages
IEEE, 2012
Keyword
Bandwidth, Delay, Electronic mail, Optical fiber networks, Real time systems, Telemedicine, WDM networks
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-85544 (URN)10.1109/ONDM.2012.6210281 (DOI)978-1-4673-1441-1 (ISBN)978-1-4673-1440-4 (ISBN)
Conference
16th International Conference on Optical Network Design and Modeling (ONDM), 17-20 April, Colchester, UK
Available from: 2012-11-22 Created: 2012-11-22 Last updated: 2015-03-23Bibliographically approved
3. Trading Quality of Transmission for Improved Blocking Performance in All-Optical Networks
Open this publication in new window or tab >>Trading Quality of Transmission for Improved Blocking Performance in All-Optical Networks
2013 (English)In: Asia Communications and Photonics Conference 2013, 2013, AF4E.5- p.Conference paper, Published paper (Refereed)
Abstract [en]

We propose a connection provisioning strategy in dynamic all-optical networks, which exploit the possibility to allow a tolerable signal quality degradation during a small fraction of holding-time resulting in a significant improvement of blocking performance.

Keyword
All-optical networks; Networks, network optimization; Networks, wavelength routing
National Category
Computer and Information Science Computer Science
Identifiers
urn:nbn:se:liu:diva-115903 (URN)10.1364/ACPC.2013.AF4E.5 (DOI)978-1-55752-989-3 (ISBN)
Conference
Asia Communications and Photonics Conference, November 12-15, Beijing, China
Available from: 2015-03-23 Created: 2015-03-23 Last updated: 2015-04-08Bibliographically approved
4. An Optimization Model for Dynamic Bulk Provisioning in Elastic Optical Networks
Open this publication in new window or tab >>An Optimization Model for Dynamic Bulk Provisioning in Elastic Optical Networks
Show others...
2014 (English)In: Asia Communications and Photonics Conference 2014, Optics Info Base, Optical Society of America, 2014, AF3E.6- p.Conference paper, Published paper (Refereed)
Abstract [en]

We investigate benefits of setup-delay tolerance in elastic optical networks and propose an optimization model for dynamic and concurrent connection provisioning. Simulation shows that the proposed strategy offers significant improvement of the network blocking performance.

Place, publisher, year, edition, pages
Optics Info Base, Optical Society of America, 2014
Keyword
Fiber optics and optical communications; Networks, network optimization
National Category
Information Systems Computer Science
Identifiers
urn:nbn:se:liu:diva-115904 (URN)10.1364/ACPC.2014.AF3E.6 (DOI)2-s2.0-84918576254 (Scopus ID)978-1-55752-852-0 (ISBN)
Conference
Asia Communications and Photonics Conference, November 11-14, Shanghai, China
Available from: 2015-03-23 Created: 2015-03-23 Last updated: 2015-04-08Bibliographically approved
5. Introducing Flexible and Synthetic Optical Networking: Planning and Operation Based on Network Function Programmable ROADMs
Open this publication in new window or tab >>Introducing Flexible and Synthetic Optical Networking: Planning and Operation Based on Network Function Programmable ROADMs
Show others...
2014 (English)In: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 6, no 7, 635-648 p.Article in journal (Refereed) Published
Abstract [en]

Elastic optical networks are envisaged as promising solutions to fulfill the diverse bandwidth requirements for the emerging heterogeneous network applications. To support flexible allocation of spectrum resources the optical network nodes need to be agile. Among the different proposed solutions for elastic nodes, the one based on architecture of demand (AoD) exhibits considerable flexibility against the other alternatives. The node modules in the case of AoD are not hard-wired, but can be connected/disconnected to any input/output port according to the requirements. Thus, each AoD node and the network (fabricated with AoD nodes) as a whole acts like an optical field-programmable gate array. This flexibility inherent in AoD can be exploited for different purposes, such as for cost-efficient and energy-efficient design of the networks. This study looks into the cost-efficient network planning issue for synthetic networks implemented through AoD nodes. The problem is formalized as an integer linear programming formulation for presenting the optimal solution. Furthermore, a scalable and effective heuristic algorithm is proposed for cost-efficient design, and its performance is compared with the optimal solution. The designed networks with AoD nodes are further investigated for a dynamic scenario, and their blocking probability due to limited switching resources in the nodes is examined. To alleviate the blocking performance for the dynamic case, an efficient synthesis strategy along with a scheme for optimal placement of switching resources within the network nodes is presented. Extensive results show that 1) even at high loads, the network with AoD nodes achieves saving of switching modules up to 40% compared to the one with static reconfigurable optical add-drop multiplexers (ROADMs) through a proper network design, 2) by diminishing the spectrum selective switches the overall power consumption of the network decreases by more than 25% for high loads, and 3) for the dynamic scenario the blocking owing to the node modules constraint is alleviated significantly by slightly augmenting the switching devices and optimally deploying them within the network nodes.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2014
Keyword
Architecture on demand; Dynamic traffic; Energy-efficient; Flexible and synthetic optical networks; Network planning; Optical cross-connect; Routing and spectrum allocation
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-109232 (URN)10.1364/JOCN.6.000635 (DOI)000338924800006 ()
Available from: 2014-08-12 Created: 2014-08-11 Last updated: 2017-12-05Bibliographically approved
6. Dynamic provisioning utilizing redundant modules in elastic optical networks based on architecture on demand nodes
Open this publication in new window or tab >>Dynamic provisioning utilizing redundant modules in elastic optical networks based on architecture on demand nodes
Show others...
2014 (English)In: European Conference on Optical Communication (ECOC), 2014, IEEE , 2014, 1-3 p.Conference paper, Published paper (Refereed)
Abstract [en]

Survivable synthetic ROADMs are equipped with redundant switching modules to support failure recovery. The paper proposes a dynamic connection provisioning strategy which exploits these idle redundant modules to provision regular traffic resulting in a substantial improvement in the blocking performance.

Place, publisher, year, edition, pages
IEEE, 2014
Keyword
optical fibre networks; telecommunication traffic; demand nodes; dynamic connection provisioning strategy; dynamic provisioning; elastic optical networks; failure recovery; redundant switching modules; survivable synthetic ROADM; Availability; Educational institutions; Optical add-drop multiplexers; Optical fiber networks; Optical switches; Ports (Computers)
National Category
Information Systems Computer Science
Identifiers
urn:nbn:se:liu:diva-115906 (URN)10.1109/ECOC.2014.6963998 (DOI)2-s2.0-84915818579 (Scopus ID)
Conference
European Conference on Optical Communication (ECOC), 2014, September 21-25, Cannes, France
Available from: 2015-03-23 Created: 2015-03-23 Last updated: 2015-04-08Bibliographically approved
7. Routing, Spectrum and Core Allocation in Flexgrid SDM Networks with Multi-core Fibers
Open this publication in new window or tab >>Routing, Spectrum and Core Allocation in Flexgrid SDM Networks with Multi-core Fibers
2014 (English)In: 2014 INTERNATIONAL CONFERENCE ON OPTICAL NETWORK DESIGN AND MODELING, IEEE , 2014, 192-197 p.Conference paper, Published paper (Refereed)
Abstract [en]

Space division multiplexing (SDM) over multi-core fiber (MCF) is advocated as a promising technology to overcome the capacity limit of the current single-core optical networks. However, employing the MCF for flexgrid networks necessitates the development of new concepts, such as routing, spectrum and core allocation (RSCA) for traffic demands. The introduction of MCF in the networks mitigates the spectrum continuity constraint of the routing and spectrum assignment (RSA) problem. In fact cores can be switched freely on different links during routing of the network traffic. Similarly, the route disjointness for demands with same allocated spectrum diminishes to core disjointness at the link level. On the other hand, some new issues such as the inter-core crosstalk should be taken into account while solving the RSCA problem. This paper formulates the RSCA network planning problem using the integer linear programming (ILP) formulation. The aim is to optimally minimize the maximum number of spectrum slices required on any core of MCF of a flexgrid SDM network. Furthermore, a scalable and effective heuristic is proposed for the same problem and its performance is compared with the optimal solution. The results show that the proposed algorithm is able to well approximate the optimal solution based on ILP model.

Place, publisher, year, edition, pages
IEEE, 2014
Keyword
Space division multiplexing (SDM); multi-core fiber (MCF); inter-core crosstalk; network planning; flexgrid networks
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-112320 (URN)000343647500033 ()978-3-901882-60-9 (ISBN)
Conference
18th International Conference on Optical Network Design and Modeling (ONDM)
Available from: 2014-11-24 Created: 2014-11-24 Last updated: 2015-03-23
8. Flexible and Synthetic SDM Networks with Multi-core-Fibers Implemented by Programmable ROADMs
Open this publication in new window or tab >>Flexible and Synthetic SDM Networks with Multi-core-Fibers Implemented by Programmable ROADMs
Show others...
2014 (English)In: Proceedings of European Conference on Optical Communication ECOC2014, Cannes, France, September 21-25 September 2014, IEEE , 2014, 1-3 p.Conference paper, Published paper (Refereed)
Abstract [en]

This study looks into network planning issues for synthetic MCF-based SDM networks implemented through programmable ROADMs. The results show that significant savings in switching modules and energy can be attained by exploiting the flexibility inherent in programmable ROADM through a proper network design.

Place, publisher, year, edition, pages
IEEE, 2014
National Category
Electrical Engineering, Electronic Engineering, Information Engineering Information Systems
Identifiers
urn:nbn:se:liu:diva-115907 (URN)10.1109/ECOC.2014.6963910 (DOI)
Conference
European Conference on Optical Communication ECOC2014, Cannes, France, September 2014
Available from: 2015-03-23 Created: 2015-03-23 Last updated: 2015-03-23Bibliographically approved

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Muhammad, Ajmal

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  • apa
  • harvard1
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  • oxford
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