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  • 1. Abeywickrama, S.
    et al.
    Furdek, Marija
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab). University of Zagreb, Faculty of Electrical Engineering and Computing, Dept. of Telecommunications, Croatia.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Nag, A.
    Wong, E.
    Dual-homing based protection for enhanced network availability and resource efficiency2014Inngår i: Asia Communications and Photonics Conference, ACP, 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    An approach to enhance core network survivability by utilizing dual-homing capabilities of the access network. Results reveal significant improvements in core network resource utilization and connection availability, suggesting benefits to network operators and service providers.

  • 2. Abeywickrama, S.
    et al.
    Wong, E.
    Furdek, Marija
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Energy-efficient survivability for core networks using dual-homing2015Inngår i: Asia Communications and Photonics Conference, ACPC 2015, 2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper studies the energy efficiency of exploiting dual-homing in access network to provide core network survivability. Simulation results show reduced number of utilized wavelengths, suggesting significant energy saving opportunities in the core network. © 2015 OSA.

  • 3. Abeywickrama, Sandu
    et al.
    Furdek, Marija
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wong, Elaine
    Protecting core networks with dual-homing: A study on enhanced network availability, resource efficiency, and energy-savings2016Inngår i: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 381, s. 327-335Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Core network survivability affects the reliability performance of telecommunication networks and remains one of the most important network design considerations. This paper critically examines the benefits arising from utilizing dual-homing in the optical access networks to provide resource-efficient protection against link and node failures in the optical core segment. Four novel, heuristic-based RWA algorithms that provide dedicated path protection in networks with dual-homing are proposed and studied. These algorithms protect against different failure scenarios (i.e. single link or node failures) and are implemented with different optimization objectives (i.e., minimization of wavelength usage and path length). Results obtained through simulations and comparison with baseline architectures indicate that exploiting dual-homed architecture in the access segment can bring significant improvements in terms of core network resource usage, connection availability, and power consumption.

  • 4. Abeywickrama, Sandu
    et al.
    Furdek, Marija
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wong, Elaine
    Protecting core networks with dual-homing: A study on enhanced network availability, resource efficiency, and energy-savings2016Inngår i: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 381, s. 327-335Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Core network survivability affects the reliability performance of telecommunication networks and remains one of the most important network design considerations. This paper critically examines the benefits arising from utilizing dual-homing in the optical access networks to provide resource-efficient protection against link and node failures in the optical core segment. Four novel, heuristic-based RWA algorithms that provide dedicated path protection in networks with dual-homing are proposed and studied. These algorithms protect against different failure scenarios (i.e. single link or node failures) and are implemented with different optimization objectives (i.e., minimization of wavelength usage and path length). Results obtained through simulations and comparison with baseline architectures indicate that exploiting dual-homed architecture in the access segment can bring significant improvements in terms of core network resource usage, connection availability, and power consumption.

  • 5.
    Ahmed, J
    et al.
    KTH.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Spadaro, S
    Enhancing restoration performance using service relocation in PCE-based resilient optical clouds2014Inngår i: Conference on Optical Fiber Communication, Technical Digest Series, 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper investigates the benefits of dynamic restoration with service relocation in resilient optical clouds. Results from the proposed optimization model show that service availability can be significantly improved by allowing a few service relocations.

  • 6.
    Ahmed, Jawwad
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Cavdar, Cicek
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    A Dynamic Bulk Provisioning Framework for Concurrent Optimization in PCE-Based WDM Networks2012Inngår i: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 30, nr 14, s. 2229-2239Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A centralized network control and management plane, such as the one based on a path computation element (PCE), is highly beneficial in terms of resource optimization in wavelength division multiplexing optical networks. Benefits of centralized provisioning are even more evident when connection requests are provisioned in batches, i.e., they allow a better use of network resources via concurrent optimization. In this study, a dynamic bulk provisioning framework is presented with the objective of optimizing the use of network resources that also presents, as an additional benefit, the ability to yield a reduction of the control plane overhead. The rationale behind the proposed framework is based on a mechanism in which the PCE client is allowed to bundle and simultaneously send multiple labeled switch path (LSP) requests to the PCE where, in turn, several bundles can be concurrently processed together as a single bulk. From the network deployment perspective, a PCE-based network architecture is proposed to practically realize this approach. For dynamic bulk provisioning of optical LSP requests, a time-efficient integer linear programming (ILP) model (LSP BP ILP) is presented to minimize the request blocking, the network resource consumption, and the network congestion. In addition, a heuristic based on a greedy randomized adaptive search procedure (GRASP), namely LSP_BP_GRASP, is also proposed as a scalable alternative. The presented results demonstrate significant advantages of the proposed PCE bulk provisioning framework based on concurrent optimization in terms of reduced blocking probability and control overhead when compared with conventional dynamic connection provisioning approaches processing a single connection request at a time.

  • 7.
    Ahmed, Jawwad
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Cavdar, Cicek
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    An Optimal Model for LSP Bundle Provisioning in PCE-based WDM Networks2011Inngår i: 2011 Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference, OFC/NFOEC 2011, Washington: Optical Society of America , 2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A time-efficient resource optimization model for dynamic concurrent provisioning of connection requests at PCE is proposed. It is shown that a significant performance improvement can be achieved without noticeable increase in connection setup-time.

  • 8.
    Ahmed, Jawwad
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Cavdar, Cicek
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Bulk provisioning of LSP requests with shared path protection in a PCE-based WDM network2011Inngår i: ONDM 2011 - 15th Conference on Optical Network Design and Modeling, 2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The Path Computation Element (PCE) is a network entity utilized for network path computation operations, especially useful in optical networks based on wavelength division multiplexing (WDM). In the PCE paradigm, the communication between a node and the PCE is specified by the Path Computation Element Communication Protocol (PCEP). According to PCEP protocol, multiple LSP (Label Switched Path) requests can be bundled together before being sent to the PCE in order to reduce the control overhead. Multiple bundles received by the PCE can then be provisioned at once as a single bulk. Enabling bulk provisioning of LSP requests at the PCE in a concurrent manner can bring significant improvements in terms of higher network resource utilization and control plane overhead reduction. However, these advantages come at a cost of a longer connection setup-time and of an instantaneous increase in the network load, which may lead to a degradation of the network performance, e.g. blocking probability. In this study pros and cons of bulk provisioning are explored in shared path protection (SPP) by comparing sequential and concurrent path computation strategies. An efficient meta-heuristic named GRASP-SPP-BP (Greedy Random Adoptive Search Procedure for Shared Path Protection with Bulk Provisioning) is proposed for concurrent provisioning of primary and shared backup path pairs. GRASP-SPP-BP minimizes the backup resource consumption while requiring minimal path computation time. The presented results demonstrate that, in a SPP network scenario, a significant reduction in the PCEP control overhead, network blocking probability and backup resource consumption can be achieved via LSP bulk provisioning at the PCE with the proposed GRASP-SPP-BP approach.

  • 9.
    Ahmed, Jawwad
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Cavdar, Cicek
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Hybrid Survivability Schemes Achieving High Connection Availability With a Reduced Amount of Backup Resources2013Inngår i: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 5, nr 10, s. A152-A161Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Maximizing connection availability in WDM networks is critical because even small disruptions can cause huge data losses. However, there is a trade-off between the level of network survivability and the cost related to the backup resources to be provided. The 100% survivability can be achieved by dedicated path protection with multiple pre-reserved protection paths for each provisioned connection, i.e., DPP (1:N). Unfortunately, the blocking probability performance of DPP (1:N) is negatively affected by the large number of pre-reserved backup wavelengths standing-by unutilized. On the other hand, path restoration (PR)-based solutions ensure good blocking performance at the expense of lower connection availability.

    The work in this paper aims at finding hybrid network survivability strategies that combine the benefits of both techniques (i.e., high availability with low blocking rate). More specifically, the paper focuses on a double link failure scenario and proposes two strategies. The first one, couples dedicated path protection DPP (1:1) with path restoration (referred to as DPP + PR) to minimize the number of dropped connections. The second scheme adds up the concept of backup reprovisioning (BR), referred to as DPP + BR + PR, in order to further increase the connection availability achieved by DPP + PR. Integer Linear Programming (ILP) models for the implementation of the proposed schemes are formulated. Extensive performance evaluation conducted in a PCE-based WDM network scenario shows that DPP + BR + PR and DPP + PR can significantly lower the blocking probability value compared to DPP (1:2) without compromising too much in terms of connection availability.

  • 10.
    Ahmed, Jawwad
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Cavdar, Cicek
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Survivability strategies for PCE-based WDM networks offering high reliability performance2013Inngår i: 2013 Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference, OFC/NFOEC 2013, Optical Society of America, 2013, s. 6532695-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Two approaches based on backup reprovisioning and path restoration are proposed for dynamic failure recovery in survivable, PCE-based, WDM networks. Results show that proposed schemes can achieve high connection availability in double link failure scenarios.

  • 11.
    Ahmed, Jawwad
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Benefits of Connection Request Bundling in a PCE-based WDM Network2009Inngår i: Proc. of European Conference on Networks and Optical Communications (NOC), 2009Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The  Path  Computation  Element  (PCE)  concept  is  considered  to  be  beneficial  in  the network  connection  setup  operations,  especially  in  optical  networks  based  on wavelength  division  multiplex  (WDM)  transport  technology.  In  the  PCE  paradigm, communication  between  a  node  and  the  PCE  is  specified  by  the  Path  Computation Element  Communication  Protocol  (PCEP).  PCEP  allows  the  PCC  (Path  Computation Client) to send to the PCE more than one LSP (path computation) request at a time, i.e., multiple LSP requests can be bundled together before being sent to the PCE. Enabling bundling, and consequently the concurrent optimization of a large set of LSP requests at the PCE, may result in significant improvements in terms of network optimization and reduced  control  plane  overhead.  However,  these  advantages  come  at  a  cost  of increased  connection  setup-delay.  This  paper  explores  pros  and  cons  of  enabling bundling of LSP requests in terms of both control plane overhead reduction and benefits of  sequential  vs.  concurrent  path  computation  operations.  A  variety  of  scenarios  are analyzed,  including  a  WDM  mesh  network  providing  LSPs  with  both  dedicated  and shared  path  protection.  Results  demonstrate  significant  gains  in  terms  of  reduced control  overhead  using  LSP  bundling,  and  reduction  in  blocking  probability  using concurrent processing of bundled LSP requests at the PCE.

  • 12.
    Ahmed, Jawwad
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Concurrent processing of multiple LSP request bundles on a PCE in a WDM network2010Inngår i: 2010 Conference on Optical Fiber Communication, Collocated National Fiber Optic Engineers Conference, OFC/NFOEC, New York: IEEE , 2010, s. 5465298-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Concurrent RWA algorithm for differentiated services to process multiple LSP bundles at PCE is proposed. Significant blocking probability reduction has been observed at the expense of slightly increased LSP setup-time compared to a sequential approach.

  • 13.
    Ahmed, Jawwad
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    LSP Request Bundling in a PCE-Based WDM Network2009Inngår i: OFC: 2009 Conference on Optical Fiber Communication, IEEE , 2009, s. 989-991Konferansepaper (Fagfellevurdert)
    Abstract [en]

    LSP requests may be bundled to improve the network optimization process at the expense of an increased connection setup delay. A detailed study is conducted to evaluate the pros and cons of the bundling approach.

  • 14.
    Ahmed, Jawwad
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Solano, Fernando
    Warsaw University of Technology.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Traffic re-optimization strategies for dynamically provisioned WDM networks2011Inngår i: ONDM 2011 - 15th Conference on Optical Network Design and Modeling, Bologna, 2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In Wavelength Division Multiplexed (WDM) networks with dynamic lightpath provisioning, connection requests are served without any prior knowledge of their arrival and departure times. As time passes, network resources may become fragmented because of the network dynamism. Under these circumstances it is highly beneficial to re-optimize (i.e., de-fragment) the existing lightpath configuration at some specific time instances to improve the network resource utilization and reduce the risk that future connection requests will be blocked. Assuming that this de-fragmentation process occurs during a re-optimization phase, this paper presents a set of strategies which govern the time instances when this re-optimization phase should be triggered as well as a set of strategies to decide which of the currently active lightpaths should be optimized at any given re-optimization phase. These strategies are referred to as when-to-re-optimize (when-t-r) and what-to-re-optimize (what-t-r) strategies, respectively. During the evaluation process particular attention is devoted to study the impact that when-t-r and what-t-r strategies have on the traffic disruption metrics (i.e., number of total disrupted connections, disruption time, reconfiguration time) inherent with the re-optimization process. Based on the evaluation results, it can be concluded that the choice of an optimal "when" and an optimal "what" to re-optimize strategy is dependent upon the performance objective (e.g. lower blocking probability or network disruption) in a given network scenario.

  • 15.
    Billenahalli, Shreejith
    et al.
    The University of Texas at Dallas.
    Razo, Miguel
    The University of Texas at Dallas.
    Huang, Wanjun
    The University of Texas at Dallas.
    Sivasankaran, Arularasi
    The University of Texas at Dallas.
    Tang, Limin
    The University of Texas at Dallas.
    Vardhan, Hars
    The University of Texas at Dallas.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Tacca, Marco
    The University of Texas at Dallas.
    Fumagalli, Andrea
    The University of Texas at Dallas.
    A wavelength sharing and assignment heuristic to minimize the number of wavelength converters in resilient WDM networks2009Inngår i: Proceedings of the 2009 7th International Workshop on the Design of Reliable Communication Networks, DRCN 2009 / [ed] Medhi, D; Tipper, D; Doucette, J, 2009, s. 319-326Konferansepaper (Fagfellevurdert)
    Abstract [en]

    With the successful introduction of reconfigurable optical add-drop multiplexers (ROADMs) and related technologies, WDM networks are now growing in the number of optical nodes, wavelengths, and lambda services supported. In addition, shared path protection mechanisms - whereby lambda services are allowed to share protection wavelength channels - are possible at the optical (WDM) layer. Efficient strategies must be devised to both determine the set of services that must share a common protection wavelength channel and assign wavelengths to every service. One objective of these strategies is to minimize the total number of wavelength converters (WCs), which are required every time the wavelength continuity constraint cannot be met. This paper presents a scalable and efficient heuristic, whose goal is to minimize the number of WCs in resilient WDM networks supporting static sets of shared path protection lambda services. The heuristic comprises a set of polynomial algorithms that are executed sequentially to obtain a sub-optimal solution. In small size instances of the problem, the heuristic is compared against the optimal solution obtained from ILP formulation. For large size instances - tens of thousands of lambda services and hundreds of nodes - the heuristic yields an average number of WCs that is close to be linear in the number of services, despite the fact that the wavelength sharing factor increases.

  • 16.
    Cavdar, Cicek
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Ruiz, M.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Velasco, L.
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Design of green optical networks with signal quality guarantee2012Inngår i: IEEE International Conference on Communications, IEEE , 2012, s. 3025-3030Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Energy consumption of communication networks is growing very fast due to the rapidly increasing traffic demand. Consequently, design of green communication networks gained a lot of attention. In this paper we focus on optical Wavelength Division Multiplexing (WDM) networks, able to support this growing traffic demand. Several energy-aware routing and wavelength assignment (EA-RWA) techniques have been proposed for WDM networks in order to minimize their operational cost. These techniques aim at minimizing the number of active links by packing the traffic as much as possible, thus avoiding the use of lightly loaded links. As a result, EA-RWA techniques may lead to longer routes and to a high utilization on some specific links. This has a detrimental effect on the signal quality of the optical connections, i.e., lightpaths. In this study we quantify the impact of power consumption minimization on the optical signal quality. and address this problem by proposing a combined impairment and energy-aware RWA (IEA-RWA) approach. Towards this goal we developed a complete mathematical model that incorporates both linear and non-linear physical impairments together with an energy efficiency objective. The IEA-RWA problem is formulized as a Mixed Integer Linear Programming (MILP) model where both energy efficiency and signal quality considerations are jointly optimized. By comparing the proposed IEA-RWA approach with existing RWA (IA-RWA and EA-RWA) schemes, we demonstrate that our solution allows for a reduction of energy consumption close to the one obtained by EA-RWA approaches, while still guaranteeing a sufficient level of the optical signal quality.

  • 17.
    Cerutti, Isabella
    et al.
    Scuola Superiore Sant'Anna.
    Fumagalli, Andrea
    The University of Texas at Dallas.
    Hui, Rongqing
    The University of Kansas.
    Monti, Paolo
    The University of Texas at Dallas.
    Paradisi, Alberto
    CPqD.
    Tacca, Marco
    The University of Texas at Dallas.
    Plug and Play Networking with Optical Nodes2006Inngår i: ICTON 2006: 8th International Conference on Transparent Optical Networks, Vol 3, Proceedings / [ed] Marciniak, M, 2006, Vol. 3, s. 133-138Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Plug and play optical (PPO) nodes may be used to facilitate the deployment of optical networks. PPO nodes must be able to learn about the signal propagation properties of the surrounding optical fibers and make their wavelength routing decisions based on the collected data. This paper discusses what are the open challenges that must be overcome to provide cost effective and performing ad hoc networking solutions based on PPO nodes.

  • 18.
    Cerutti, Isabella
    et al.
    Scuola Superiore Sant'Anna.
    Fumagalli, Andrea
    The University of Texas at Dallas.
    Hui, Rongqing
    The University of Kansas.
    Monti, Paolo
    The University of Texas at Dallas, United States.
    Paradisi, Alberto
    CPqD.
    Tacca, Marco
    The University of Texas at Dallas, United States.
    Plug and play optical nodes: network functionalities and built-in fiber characterization techniques2007Inngår i: Journal of Optical Networking, ISSN 1536-5379, Vol. 6, nr 6, s. 642-653Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    \textlessp\textgreater\textlessa href$=$"http://www.osa-jon.org/virtual_issue.cfm?vid$=$26"\textgreaterFeature Issue on Photonics in Switching\textless/a\textgreater\textless/p\textgreaterPlug and play optical (PPO) nodes may be used to facilitate the deployment of optical networks. PPO nodes must be able to learn about the signal propagation properties of the surrounding optical fibers and make their wavelength-routing decisions based on the collected data. We discuss what are the open challenges that must be overcome to provide optical networking solutions based on cost-effective PPO nodes. Three possible PPO node hardware architectures with trade-offs in complexity, cost, and functionality are presented along with their built-in fiber characterization techniques.

  • 19. Chiaraviglio, L.
    et al.
    Lorincz, J.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Towards sustainable and reliable networks with LIFETEL2015Inngår i: Proceedings - IEEE INFOCOM, IEEE conference proceedings, 2015, s. 39-40Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We present the LIFETEL project, whose aim is trying to increase the device lifetime in telecommunication networks by exploiting energy-efficient techniques. In particular, we show that the lifetime of a device might increase when it is put in sleep mode. However, the device lifetime might decrease when power state variations (from sleep mode to full power) occur very frequently. Thus, there is a trade-off between the duration of sleep mode and its frequency. Moreover, we report a lifetime analysis for cellular and backbone devices, showing that the electricity saving may be exceeded by the costs due to the fact that devices fail more frequently compared to the situation in which they are always powered on. Thus, we claim that energy-aware network algorithms should be redesigned in order not to impact and to increase (when possible) the lifetime of network devices.

  • 20. Chiaraviglio, L.
    et al.
    Wiatr, Paweł
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Chen, Jiajia
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Lorincz, J.
    Idzikowski, F.
    Listanti, M.
    Impact of energy-efficient techniques on a device lifetime2014Inngår i: 2014 IEEE Online Conference on Green Communications, OnlineGreenComm 2014, IEEE conference proceedings, 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper focuses on the impact that energyefficient techniques have on the component lifetime in optical backbone networks. The study presented in the paper considers in particular the influence that green routing strategies have on the failure rate of Erbium Doped Fiber Amplifiers (EDFAs), i.e., if their lifetime is positively or negatively impacted when putting them into sleep mode in order to reduce their energy consumption. To this end, the paper proposes a model that estimates the failure rate acceleration factor as a function of: (i) for how long and how frequently a device is switched into sleep mode, and (ii) hardware parameters that characterize the device. The proposed model is then evaluated by considering an energyefficient Routing and Wavelength Assignment (RWA) strategy that targets saving energy by putting EDFAs into sleep mode. The results presented in the paper show that energy-efficient techniques may have the potential to lower the failure rate of EDFAs. However, this is true only under specific conditions, i.e., an energy-efficient strategy needs to be carefully planned in order to avoid frequent power state transitions, which result in shortening the lifetime of an EDFA.

  • 21. Chiaraviglio, Luca
    et al.
    Blefari-Melazzi, Nicola
    Liu, William
    Gutierrez, Jairo A.
    Van de Beek, Jaap
    Birke, Robert
    Chen, Lydia
    Idzikowski, Filip
    Kilper, Daniel
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Wu, Jinsong
    5G in rural and low-income areas: Are we ready?2016Inngår i: PROCEEDINGS OF THE 2016 ITU KALEIDOSCOPE ACADEMIC CONFERENCE - ICTS FOR A SUSTAINABLE WORLD (ITU WT), IEEE, 2016, s. 99-106Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Current trends in telecommunication networks foresee the adoption of the,fifth generation (5G) of wireless networks in the near fixture. However; a large number of people are living without coverage and connectivity. To face this issue, we consider the possibility of deploying 5G networks in rural and low-income zones. After detailing the current state-of-the-art, we consider the main challenges that need to be faced. Moreover; we define the main pillars to follow in order to deploy 5G networks in such zones, as well as a proposal of a future network architecture.

  • 22. Chiaraviglio, Luca
    et al.
    Wiatr, Pawel
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Chen, Jiajia
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Lorincz, Josip
    Idzikowski, Filip
    Listanti, Marco
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Is Green Networking Beneficial in Terms of Device Lifetime?2015Inngår i: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 53, nr 5, s. 232-240Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This article analyzes the impact that sleep mode (SM)-based green strategies have on the reliability performance of optical and cellular network elements. First, we consider a device in isolation (i. e., not plugged into a network in operation), showing how operational temperature and temperature variations, both introduced by SM, impact its lifetime. We then evaluate, from an operational cost perspective, the impact of these lifetime variations, showing that some devices are critical, that is, their achievable energy savings might not cover the potential additional reparation costs resulting from being put in SM too frequently. Moreover, we present a model for evaluating the impact of SM on the lifetime of a device plugged into an operational network. The analysis considers two case studies (one based on the optical backbone and one on cellular networks) showing that the lifetime of a device is influenced by both the hardware parameters, which depend on the specific design of the device, and the SM parameters, which instead depend on the energy-efficient algorithm used, the network topology, and the traffic variations over time. Our results show that (i) the changes in the operational temperature and the frequency of their variation are two crucial aspects to consider while designing a SM-based green strategy, and (ii) the impact of a certain SM-based strategy on the lifetime of network devices is not homogeneous (i. e., it can vary through the network).

  • 23.
    Chiasserini, Carla-Fabiana
    et al.
    Politecnico di Torino.
    Chlamtac, Imrich
    The University of Texas at Dallas.
    Monti, Paolo
    The University of Texas at Dallas, United States.
    Nucci, Antonio
    Politecnico di Torino.
    An Energy-Efficient Method for Nodes Assignment in Cluster-Based Ad Hoc Networks2004Inngår i: Wireless networks, ISSN 1022-0038, E-ISSN 1572-8196, Vol. 10, nr 3, s. 223-231Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    One of the most critical issues in wireless ad hoc networks is represented by the limited availability of energy within network nodes. Thus, making good use of energy is a must in ad hoc networks. In this paper, we define as network lifetime the time period from the instant when the network starts functioning to the instant when the first network node runs out of energy. Our objective is to devise techniques to maximize the network lifetime in the case of cluster-based systems, which represent a significant sub-set of ad hoc networks. Cluster-based ad hoc networks comprise two types of nodes: cluster-heads and ordinary nodes. Cluster-heads coordinate all transmissions from/to ordinary nodes and forward all traffic in a cluster, either to other nodes in the cluster or to other cluster-heads. In this case, to prolong the network lifetime we must maximize the lifetime of the cluster-heads because they are the critical network element from the energy viewpoint. We propose an original approach to maximize the network lifetime by determining the optimal assignment of nodes to cluster-heads. Given the number of cluster-heads, the complexity of the proposed solution grows linearly with the number of network nodes. The network topology is assumed to be either static or slowly changing. Two working scenarios are considered. In the former, the optimal network configuration from the energy viewpoint is computed only once; in the latter, the network configuration can be periodically updated to adapt to the evolution of the cluster-heads energy status. In both scenarios, the presented solution greatly outperforms the standard assignment of nodes to cluster-heads, based on the minimum transmission power criterion.

  • 24.
    Chiasserini, Carla-Fabiana
    et al.
    Politecnico di Torino.
    Chlamtac, Imrich
    The University of Texas at Dallas.
    Monti, Paolo
    The University of Texas at Dallas.
    Nucci, Antonio
    Politecnico di Torino.
    Energy Efficient Design of Wireless Ad Hoc Networks2006Inngår i: NETWORKING 2002: Networking Technologies, Services, and Protocols; Performance of Computer and Communication Networks; Mobile and Wireless Communications / [ed] Gregori, Enrico; Conti, Marco; Campbell, Andrew; Omidyar, Guy; Zukerman, Moshe, Springer Berlin / Heidelberg , 2006, Vol. 2345, s. 376-386Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    One of the most critical issues in wireless ad hoc networks is represented by the limited availability of energy within network nodes. The time period from the instant when the network starts functioning to the instant when the first network node runs out of energy, the so-called network life- time , strictly depends on the system energy efficiency. Our objective is to devise techniques to maximize the network life-time in the case of cluster-based systems, which represent a significant sub-set of ad hoc networks. We propose an original approach to maximize the network life-time by determining the optimal clusters size and the optimal assignment of nodes to cluster-heads. The presented solution greatly outperforms the standard assignment of nodes to cluster-heads, based on the minimum distance criterion.

  • 25.
    Chincoli, Michele
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Valcarenghi, Luca
    Scuola Superiore Sant'Anna.
    Chen, Jiajia
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Investigating the Energy Savings of Cyclic Sleep with Service Guarantees in Long Reach PONs2012Inngår i: Asia Communications and Photonics Conference, ACP, 2012, s. ATh1D.3-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper evaluates what are the conditions, in terms of increased overhead time and number of optical network units (i.e., ONUs), in which cyclic sleep based techniques are effective in Long Reach PONs.

  • 26.
    Das, Shovan
    et al.
    The University of Texas at Dallas.
    Monti, Paolo
    Tacca, Marco
    The University of Texas at Dallas.
    Fumagalli, Andrea
    The University of Texas at Dallas.
    Optical Corridor Routing Protocols2007Inngår i: ICTON 2007: Proceedings of the 9th International Conference on Transparent Optical Networks, Vol 3, 2007, Vol. 3, s. 188-192Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The scalability of routing and resource advertisement protocols is a key issue in large optical networks. A commonly used solution is based on the hierarchical approach adopted in IP/MPLS-TE networks, i.e., multiple areas or autonomous systems are pre-established to contain the geographical scope of the resource advertisement protocols and the related routing information. With arbitrarily pre-established areas, routing decision might be sub-optimal. Thus, special care must be paid by the network designer to subdivide effectively the network into areas. This paper presents and discusses an alternative routing technique that attempts to improve both optimality and scalability of routing and resource advertisement protocols without requiring the use of manually pre-established areas.

  • 27.
    Das, Shovan
    et al.
    The University of Texas at Dallas.
    Roshani, Reza
    The University of Texas at Dallas.
    Monti, Paolo
    Tacca, Marco
    The University of Texas at Dallas.
    Fumagalli, Andrea
    The University of Texas at Dallas.
    A Link State Advertisement Protocol for Optical Transparency Islands2007Inngår i: 2007 WORKSHOP ON HIGH PERFORMANCE SWITCHING AND ROUTING, 2007, s. 1-6Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Plug and play optical (PPO) nodes enable fast, re-configurable, and flexible ad hoc deployment of optical networks. Once plugged, the PPO nodes provide all-optical circuits between client nodes to alleviate the electronic processing bottleneck of high speed networks. To offer these wavelength routing functionalities to client nodes the PPO nodes must self-adjust to possible changes of the optical physical topology and fiber propagation characteristics. To discover such changes the PPO nodes must make use of a link state advertisement (LSA) protocol that is scalable in the number of plugged PPO nodes. This paper describes a scalable LSA protocol with constrained message flooding to match the limited propagation reach of the optical signal, i.e., the PPO node transparency island (TI). Scalability is thus achieved naturally by limiting the link state advertisement scope to only those PPO nodes that need to receive the link updates. As discussed in the paper, the proposed protocol appears to be a viable solution when the TI size is relatively small, e.g., in optical networks without signal regeneration.

  • 28. Farias, Fabricio
    et al.
    Fiorani, Matteo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Tombaz, Sibel
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Mahloo, Mozhgan
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Costa, Joao C. W. A.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Cost- and energy-efficient backhaul options for heterogeneous mobile network deployments2016Inngår i: Photonic network communications, ISSN 1387-974X, E-ISSN 1572-8188, Vol. 32, nr 3, s. 422-437Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Heterogeneous networks (HetNets) have the potential to cater for the capacity requirements of mobile broadband services at reduced cost and energy consumption levels. One key aspect in HetNets is the role of the backhaul. More specifically, it is crucial for a mobile operator to understand the impact of specific technological and architectural upgrades in the mobile backhaul network on the capital and operational expenditure (i.e., CAPEX and OPEX). This paper proposes a comprehensive methodology that can be used to analyze the total cost of ownership of a number of backhaul options based on fiber, microwave, and copper technologies. The study considers both a Greenfield and a Brownfield scenario and takes into account the mobile broadband capacity requirements for the time period between years 2015 and 2025. From the results presented in the paper it can be concluded that even though microwave and fiber will be predominately used in the future, the possible migration paths leading to such fiber- and microwave-based backhaul scenarios might be different, depending upon factors such as spectrum and license costs, time to deployment, availability of equipment, and required quality of service levels.

  • 29. Farias, Fabricio S.
    et al.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Västberg, Anders
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab).
    Nilsson, Mats
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Costa, J. C. W. A.
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Green backhauling for heterogeneous mobile access networks: What are the challenges?2013Inngår i: 2013 9th International Conference on Information, Communications and Signal Processing (ICICS), IEEE Computer Society, 2013, s. 6782868-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Heterogeneous network (HetNet) deployment strategies have the potential to improve the energy efficiency of mobile access networks. One key aspect to consider in HetNets is the impact of the power consumption of the backhaul, i.e., the overall energy efficiency of a HetNet deployment is affected by the backhaul technology and architecture. This paper presents a preliminary assessment of the design challenges of a future green backhaul segment for a HetNet deployment. The study is based on the analysis of the medium term future outlook (i.e., between now and the year 2025) of the main technologies used in todays'* backhaul networks (i.e., fiber, microwave and copper). It can be concluded that, even if there arc no doubts that both microwave and fiber will be predominately used in the future, the possible migration paths leading to such fiber- and microwave-dominated scenarios might be different, depending on factors such as spectrum and license costs, time to deployment, availability of equipment, and required Quality of Service (QoS) levels.

  • 30. Fiammengo, Martina
    et al.
    Lindström, Alexander
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Skubic, Björn
    Experimental evaluation of cyclic sleep with adaptable sleep period length for PON2011Inngår i: European Conference on Optical Communication, ECOC, Geneva, 2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    An experimental evaluation of cyclic sleep for PON is presented where different control algorithms for adaptable sleep length period are compared.

  • 31. Fiorani, Matteo
    et al.
    Aleksic, Slavisa
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Chen, Jiajia
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Casoni, Maurizio
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Energy Efficiency of an Integrated Intra-Data-Center and Core Network With Edge Caching2014Inngår i: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 6, nr 4, s. 421-432Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The expected growth of traffic demand may lead to a dramatic increase in the network energy consumption, which needs to be handled in order to guarantee scalability and sustainability of the infrastructure. There are many efforts to improve energy efficiency in communication networks, ranging from the component technology to the architectural and service-level approaches. Because data centers and content delivery networks are responsible for the majority of the energy consumption in the information and communication technology sector, in this paper we address network energy efficiency at the architectural and service levels and propose a unified network architecture that provides both intra-data-center and inter-data-center connectivity together with interconnection toward legacy IP networks. The architecture is well suited for the carrier cloud model, where both data-center and telecom infrastructure are owned and operated by the same entity. It is based on the hybrid optical switching (HOS) concept for achieving high network performance and energy efficiency. Therefore, we refer to it as an integrated HOS network. The main advantage of the integration of core and intra-data-center networks comes from the possibility to avoid the energy-inefficient electronic interfaces between data centers and telecom networks. Our results have verified that the integrated HOS network introduces a higher number of benefits in terms of energy efficiency and network delays compared to the conventional nonintegrated solution. At the service level, recent studies demonstrated that the use of distributed video cache servers can be beneficial in reducing energy consumption of intra-data-center and core networks. However, these studies only take into consideration conventional network solutions based on IP electronic switching, which are characterized by relatively high energy consumption. When a more energy-efficient switching technology, such as HOS, is employed, the advantage of using distributed video cache servers becomes less obvious. In this paper we evaluate the impact of video servers employed at the edge nodes of the integrated HOS network to understand whether edge caching could have any benefit for carrier cloud operators utilizing a HOS network architecture. We have demonstrated that if the distributed video cache servers are not properly dimensioned they may have a negative impact on the benefit obtained by the integrated HOS network.

  • 32.
    Fiorani, Matteo
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Skubic, B.
    Martensson, J.
    Valcarenghi, L.
    Castoldi, P.
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Challenges for 5G transport networks2014Inngår i: 2014 IEEE International Conference on Advanced Networks and Telecommunication Systems, ANTS 2014, IEEE conference proceedings, 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    5G mobile communications is seen as the enabler for the networked society where connectivity will be available anywhere and anytime to anyone and anything. The details of 5G are the subject to ongoing research and debate, mostly focused on understanding radio technologies that can enable the 5G vision. So far, less work has been dedicated to the challenges that 5G will pose to the transport network. This paper provides a first analysis of the key challenges to 5G transport in terms of capacity, flexibility and costs, for example. Different use cases are discussed as well as technology options and control plane concepts. © 2014 IEEE.

  • 33.
    Fiorani, Matteo
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab). Kungliga Tekniska högskolan.
    Rostami, Ahmad
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Abstraction Models for Optical 5G Transport Networks2016Inngår i: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 8, nr 9, s. 656-665Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The orchestration of radio, transport, and cloud resources is a key enabler for efficient service delivery in 5G networks. Orchestration can be achieved with a hierarchical software-defined networking (SDN) control architecture in which a global orchestrator operates above the domain controllers. In such an architecture, the abstraction of resources between the controllers and the orchestrator plays a fundamental role for the system performance. In order to reduce the orchestrator complexity, the controllers should hide as much detail as possible from the orchestrator. On the other hand, the more details are available to the orchestrator the more optimal resource orchestration strategy can be obtained. In order to assess this trade-off, we recently proposed two transport abstraction models, namely big switch (BiS) and virtual link (VL), for centralized radio access networks (C-RANs) with orchestration of radio and transport resources. We observed that VL can provide a more efficient resource orchestration than BiS at the expense of an increased implementation complexity. The contribution of this paper is twofold. We extend the BiS and VL models to make them applicable to any orchestration scenario. Then, we propose a new transport abstraction model, referred to as optical transport transformation (OTT), that aims at achieving efficient resource orchestration with a reduced implementation complexity. We compare the performance of these new abstraction models in a C-RAN use case in which backhaul and fronthaul traffic are carried over a dense wavelength division multiplexing (DWDM) network. Our results prove that in a C-RAN the best choice for the transport abstraction model depends on the availability and the reachability of the radio resources. If radio resources are scarce compared to transport resources, complex transport abstraction models are not needed and a BiS abstraction is the best choice. On the other hand, if radio resources are widely available and reachable, an OTT model guarantees the best overall performance.

  • 34.
    Fiorani, Matteo
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Rostami, Ahmad
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Transport Abstraction Models for an SDN-Controlled Centralized RAN2015Inngår i: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 19, nr 8, s. 1406-1409Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In a centralized radio access network (C-RAN) scenario the joint coordination of radio (e.g., remote radio units, baseband units) and transport (e.g., optical cross connects) resources can be achieved via software defined networking (SDN) control plane, where a global orchestrator harmonizes the use of resources across all network segments. The more accurate the information about each domain (i.e., the abstraction of wireless and transport resources) is, the better will be the outcome of the orchestration work. This letter presents three transport resources abstraction models along with their corresponding orchestration policies. Their performance are compared showing that there is not a single best abstraction strategy that fits all the cases. If radio resources are scarce compared to transport resources, complex transport abstraction models are not needed. Contrariwise, if enough radio resources are widely available, more detailed abstraction models are required for achieving good network performance, but at the expense of an increased implementation complexity.

  • 35.
    Fiorani, Matteo
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Skubic, B.
    Mårtensson, J.
    Valcarenghi, L.
    Castoldi, P.
    Wosinska, L.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    On the design of 5G transport networks2015Inngår i: Photonic network communications, ISSN 1387-974X, E-ISSN 1572-8188, Vol. 30, nr 3, s. 403-415Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Future 5G systems will pave the way to a completely new societal paradigm where access to information will be available anywhere, anytime, and to anyone or anything. Most of the ongoing research and debate around 5G systems are focusing on the radio network segment (e.g., how to offer high peak-rates per subscriber, and how to handle a very large number of simultaneously connected devices without compromising on coverage, outage probability, and latency). On the other hand, understanding the impact that 5G systems will have on the transport network (i.e., the segment in charge of the backhaul of radio base stations and/or the fronthaul of remote radio units) is also very important. This paper provides an analysis of the key architectural challenges for the design of a flexible 5G transport infrastructure able to adapt in a cost-efficient way to the plethora of requirements coming from the large number of envisioned future 5G services.

  • 36.
    Fiorani, Matteo
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab). Kungliga Tekniska högskolan.
    Tombaz, S.
    Mårtensson, J.
    Skubic, B.
    Wosinska, L.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Energy performance of C-RAN with 5G-NX radio networks and optical transport2016Inngår i: 2016 IEEE International Conference on Communications, ICC 2016, IEEE conference proceedings, 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Each mobile network architecture able to meet the traffic requirements of future 5G services comes with its own set of benefits vs. requirements for the radio and the transport segments. This paper focuses on the energy performance of four mobile network architectures, each one with different splitting options for the baseband processing functions. The radio segment under exam is based on a new radio access technology referred to as 5G-NX, while the transport segment is based on wavelength division multiplexing (WDM). The energy consumption of each mobile network architecture is weighted against (i) the benefits for the radio segment as a function of the level of centralization of the baseband processing resources and (ii) the required transport capacity and consequently the power consumption levels needed to accommodate the backhaul, midhaul, and/or fronthaul traffic generated at each base station. Our results show that a fully centralized radio access network (C-RAN) with centralization of all the baseband functions is not a practical approach for 5G mobile networks, while a partially centralized C-RAN architecture in which the physical layer baseband processing is performed at the base station site represents a promising solution.

  • 37.
    Fiorani, Matteo
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Tombaz, S.
    Mårtensson, J.
    Skubic, Björn
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Modeling energy performance of C-RAN with optical transport in 5G network scenarios2016Inngår i: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 8, nr 11, artikkel-id B21Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The deployment of new 5G wireless interfaces based on massive multiantenna transmission and beamforming is expected to have a significant impact on the complexity and power consumption of the transport network. This paper analyzes the energy performance of four radio access network (RAN) architectures, each one utilizing a different option for splitting the baseband processing functions. The radio segment is based on Long-Term Evolution (LTE) and 5G radio access technologies. The transport segment is based on optical wavelength division multiplexing, where coherent and direct detection transmissions are considered. The energy consumption of each RAN architecture is weighted against i) the benefits for the radio segment as a function of the level of centralization of the baseband processing functions and ii) the power consumption levels needed to accommodate the capacity generated at each base station. Results show that, with LTE radio interfaces, the energy consumption of the transport network amounts to only a few percent of the overall network power consumption. As a result, fully centralized LTE radio architectures are a viable option, with energy savings of at least 27% compared with conventional distributed architectures. On the other hand, with advanced 5G radio interfaces, centralized architectures, if not carefully designed, might become impractical due to the excessive energy consumption of the transport network (i.e., as a result of the huge capacity to be accommodated). This aspect can be mitigated via a careful joint design of the radio and the transport network (i.e., leveraging on appropriate optical transmission techniques and compromising where needed on the radio network performance).

  • 38.
    Fiorani, Matteo
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Tombaz, Sibel
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Radio Systems Laboratory (RS Lab). KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Casoni, Maurizio
    University of Modena and Reggio Emilia.
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Green Backhauling for Rural Areas2014Inngår i: Green Backhauling for Rural Areas, IEEE , 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Providing wireless broadband access to rural and remote areas is becoming a big challenge for wireless operators, mostly because of the need for a cost-effective and low energy consuming mobile backhaul. However, to the best of our knowledge,energy consumption of different options for backhauling of future rural wireless broadband networks has not been studiedyet. Therefore, in this paper we assess the energy consumption of future rural wireless broadband network deployments andbackhaul technologies. In the wireless segment, two deployment strategies are considered, one with macro base station only,and one with small base stations. In the backhaul segment ,two wireless, i.e., microwave and satellite, and one optical fiber based (i.e., long reach passive optical networks) solutions areconsidered. These options are compared in terms of their abilityto satisfy coverage, capacity and QoS requirements of a numberof rural users in the time span that goes from 2010 until 2021. From the presented results it is possible to conclude that wireless backhaul solutions can significantly increase the energy consumption of the access network. In contrast, the long reach PON based backhaul has much higher energy efficiency and inthe long term might be a better choice for wireless operators.

  • 39.
    Forchheimer, Robert
    et al.
    Linköpings Universitet.
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    An optical overlay network concept for hard QoS requirements2009Inngår i: ICTON 2009: 11TH INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS, 2009, s. 1195-1198Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    It has long been argued that the best-effort strategy on which Internet is based will limit its use for real-time applications such as video or telephony. However, it has been shown that such services can indeed tolerate some jitter and rate variations through various error resilience and concealment techniques. Despite of that the Internet infrastructure is continuously upgraded with higher performance components, which further reduce the transmission problems; still there are certain classes of applications that undoubtedly will need new transmission paradigms. An example is the remote control of an industrial process that may require jitter levels down to a few microseconds. Another example is quantum cryptography where an optical transparent path between sender and receiver is to be established. In this paper we present a concept based on an optical overlay network infrastructure. This network concept can be applied in an incremental way and will enable the current network infrastructure to handle demands with such extreme QoS requirements.

  • 40. Guerzoni, R.
    et al.
    Vaishnavi, I.
    Perez caparros, D.
    Galis, A.
    Tusa, F.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Sganbelluri, Andrea
    KTH.
    Biczók, G.
    Sonkoly, B.
    Toka, L.
    Ramos, A.
    Melián, J.
    Dugeon, O.
    Cugini, F.
    Martini, B.
    Iovanna, P.
    Giuliani, G.
    Figueiredo, R.
    Contreras-Murillo, L. M.
    Bernardos, C. J.
    Santana, C.
    Szabo, R.
    Analysis of end-to-end multi-domain management and orchestration frameworks for software defined infrastructures: An architectural survey2017Inngår i: Transactions on Emerging Telecommunications Technologies, ISSN 2161-5748, Vol. 28, nr 4, artikkel-id e3103Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Over the last couple of years, industry operators' associations issued requirements towards an end-to-end management and orchestration plane for 5G networks. Consequently, standard organisations started their activities in this domain. This article provides an analysis and an architectural survey of these initiatives and of the main requirements, proposes descriptions for the key concepts of domain, resource and service slicing, end-to-end orchestration and a reference architecture for the end-to-end orchestration plane. Then, a set of currently available or under development domain orchestration frameworks are mapped to this reference architecture. These frameworks, meant to provide coordination and automated management of cloud and networking resources, network functions and services, fulfil multi-domain (i.e. multi-technology and multi-operator) orchestration requirements, thus enabling the realisation of an end-to-end orchestration plane. Finally, based on the analysis of existing single-domain and multi-domain orchestration components and requirements, this paper presents a functional architecture for the end-to-end management and orchestration plane, paving the way to its full realisation.

  • 41. Hasegawa, Hiroshi
    et al.
    Taniguchi, Y.
    Sato, K.
    Jirattigalachote, Amonrat
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Design strategies for survivable Grouped Routing Entity (GRE)-based optical networks2013Inngår i: Design of Reliable Communication Networks (DRCN), 2013 9th International Conference on the, 2013, s. 148-154Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In bandwidth abundant optical networks, the Grouped Routing Entity (GRE) concept is a cost-efficient alternative used instead of waveband routing. It offers all the benefits of the waveband routing (i.e., reduced number of ports), without using expensive wavelength cross connects (WXCs) required in hierarchical optical networks. In fact in a GRE-based optical network wavelength channel add/drop operations are accomplished via Wavelength Selective Switches (WSS) or with optical couplers. The objective of this paper is to further investigate the benefits of GRE-based optical networks in a scenario where survivability is required. In this paper a dedicated protection scheme is proposed, where wavelength paths are efficiently routed using mostly disjoint working and backup GRE pipes (i.e., working and backup pipes are allowed to share some common nodes along their paths). Numerical experiments demonstrate that significant hardware scale reduction at the switching nodes can be obtained by using the proposed network design algorithm.

  • 42. Izquierdo-Zaragoza, J. -L
    et al.
    Furdek, Marija
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Nag, A.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Pavon-Marino, P.
    On the dimensioning of survivable optical metro/core networks with dual-homed access2016Inngår i: IEEE International Conference on High Performance Switching and Routing, HPSR, IEEE Computer Society, 2016, artikkel-id 7483089Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Long-reach passive optical networks (LR-PONs) are able to effectively support the growing demand of traffic originating from residential and business customers. Failures of metro/core (M/C) nodes serving the traffic to/from the access networks covered by LR-PONs, may potentially affect hundreds or thousands of customers. One way of guaranteeing 100% survivability from single-node failures is to apply dual-homing, where each LR-PON is connected to two M/C nodes, and combine it with node-disjoint dedicated-path protection (DPP). In this paper, we present a new approach to provide network survivability against single M/C node failures. Instead of applying dedicated path protection (DPP) strategy, which can require huge amount of extra resources, we combine an unprotected network design with a dynamic multilayer restoration algorithm. Our aim is to determine a suitable amount of resource overbuild (in terms of extra transponders) needed to provide average connection availability close to that guaranteed by DPP. Preliminary results show that dimensioning for the worst-case scenario among a set of predefined M/C node failures, i.e., the one disrupting the highest number of connections, yields to a cost-effective strategy requiring up to 35% less transponders than DPP, while offering the same average connection availability.

  • 43.
    Jirattigalachote, Amornrat
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Cavdar, Cicek
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Tzanakaki, Anna
    Dynamic provisioning strategies for energy efficient WDM networks with dedicated path protection2011Inngår i: Optical Switching and Networkning Journal, ISSN 1573-4277, E-ISSN 1872-9770, Vol. 8, nr 3, s. 201-213Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Energy consumption in optical backbone networks is increasing due to two main reasons: (i) the exponential growth of bandwidth demands, and (ii) the increase in availability requirements in order to guarantee protection of the ultra high capacity optical channels provided by wavelength division multiplexing (WDM) networks. Although state of the art reliability mechanisms are very efficient in guaranteeing high availability, they do not consider the impact of the protection resources on the network's energy consumption. Dedicated (1:1) path protection (DPP) is a well-known mechanism that provides one extra link-disjoint path for the protection of a connection request. This secondary path is reserved and maintained in an active mode even though it is not utilized most of the time. This means that in-line optical amplifiers and switching nodes/ports are always consuming power even when they are not used to reroute any primary traffic. Moreover secondary paths are on average longer than their respective primary paths. These observations motivated us to investigate the energy savings, when all unused protection resources can be switched into a low-power, stand-by state (or sleep mode) during normal network operation and can be activated upon a failure. It is shown that significant reduction of power consumption (up to 25%) can be achieved by putting protection resources into sleep mode. Moreover, in order to enhance this energy saving figure, this paper proposes and evaluates different energy-efficient algorithms, specifically tailored around the sleep mode option, to dynamically provision 1:1 dedicated path protected connection. The trade-off between energy saving and blocking probability is discussed and an efficient mechanism to overcome this drawback is devised. Our results reveal that a 34% reduction of energy consumption can be obtained with a negligible impact on the network's blocking performance.

  • 44.
    Jirattigalachote, Amornrat
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Katrinis, Kostas
    Athens Information Technology.
    Tzanakaki, Anna
    Athens Information Technology.
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Quantifying the Benefit of BER-based Differentiated Path Provisioning in WDM Optical Networks2009Inngår i: ICTON: 2009 11TH INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS, VOLS 1 AND 2, NEW YORK: IEEE , 2009, s. 1097-1100Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper we propose the use of Bit Error Rate (BER) as a differentiation of service parameter for connection provisioning in optical Wavelength Division Multiplexing (WDM) networks. This is achieved through the use of Impairment Constraint Based Routing (ICBR), whereby various BER thresholds are set for accepting/blocking requests at the connection provisioning phase, depending on QoS requirements. The performance of the proposed scheme is evaluated through simulations, using dynamic traffic demands as an input at 10 Gb/s bit rate. The evaluation results reveal significant improvement in term of connection blocking, as compared to non-differentiated conventional RWA and ICBR algorithms.

  • 45.
    Jirattigalachote, Amornrat
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Katrinis, Kostas
    Athens Information Technology.
    Tzanakaki, Anna
    Athens Information Technology.
    ICBR-Diff: An Impairment Constraint Based Routing Strategy with Quality of Signal Differentiation2010Inngår i: Journal of Networks, ISSN 1796-2056, E-ISSN 1796-2056, Vol. 5, nr 11, s. 1279-1289Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Latest advances in Wavelength Division Multiplexing (WDM) technology make it possible to build all-optical transparent networks, which are considered to be able to satisfy the rapidly growing capacity demand. However, in a transparent WDM network the optical signal transmitted from a source to a destination node might be degraded due to physical layer impairments induced by transmission through optical fibers and components. Several Impairment Constraint Based Routing (ICBR) algorithms have been proposed to consider physical layer impairments during the connection-provisioning phase in order to prevent selecting a lightpath with poor signal quality. However, these algorithms support only a single quality of transmission threshold for all connection requests, while next generation networks and the future Internet are expected to support a variety of services with potentially disparate QoS requirements. In this paper, we propose the use of bit error rate (BER) as a differentiation of service parameter for connection requests in optical WDM networks. This is achieved through the use of ICBR, whereby various BER thresholds are set depending on the QoS requirements for accepting/blocking the connection requests during the connection-provisioning phase. The evaluation results reveal that significant network performance improvement in terms of connection blocking can be achieved, compared to non-differentiated conventional routing and wavelength assignment (RWA) and ICBR algorithms.

  • 46.
    Jirattigalachote, Amornrat
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Taniguchi, Yuki
    Ban, Toshinori
    Hasegawa, Hiroshi
    Sato, Ken-ichi
    Design of Grouped Routing Entity (GRE)-based Optical Networks with 100% Signal Quality Guarantee2014Inngår i: 2014 International Conference on Optical Network Design and Modeling, ONDM 2014, 2014, s. 174-179Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In bandwidth abundant optical networks it is important to develop design strategies that are not only cost effective but also able to account for the inherent characteristics of the optical transmission medium responsible for the signal quality degradation. With this objective in mind, the paper proposes a design algorithm able to determine an appropriate placement of regenerators in Grouped Routing Entity (GRE)-based optical networks. The objective of the algorithm is to guarantee a certain signal quality level to all connections while minimizing the number of fibers and switching ports required in the network The proposed design strategy relies on a physical-layer impairment model, specifically introduced in the paper for this purpose, able to estimate the signal quality of an optical path in a GRE-based optical network Simulation results indicate that compared with a single layer optical path network the proposed design algorithm can reduce at least 87% of the switch ports while the increment in the number of fibers is lower than 10%.

  • 47.
    Jirattigalachote, Amornrat
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Skorin-Kapov, Nina
    University of Zagreb.
    Furdek, Marija
    University of Zagreb.
    Chen, Jiajia
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Limiting physical-layer attack propagation with power equalization placement in transparent WDM networks2010Inngår i: 2010 Asia Communications and Photonics Conference and Exhibition, ACP 2010, 2010, s. 363-364Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We propose and evaluate a Greedy Randomized Adaptive Search Procedure applied to minimize the number of power equalizers (GRASP-PE) needed to limit the propagation of high-power jamming attacks in WDM networks. Simulation results show that GRASP-PE significantly reduces the required number of power equalizers when compared to a greedy approach.

  • 48.
    Jirattigalachote, Amornrat
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Skorin-Kapov, Nina
    Furdek, Marija
    Chen, Jiajia
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, KTH Center för Trådlösa System, Wireless@kth.
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Sparse power equalization placement for limiting jamming attack propagation in transparent optical networks2011Inngår i: Optical Switching and Networkning Journal, ISSN 1573-4277, E-ISSN 1872-9770, Vol. 8, nr 4, s. 249-258Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The latest advances in Wavelength Division Multiplexing (WDM) technology are making it possible to build all-optical transparent WDM networks, which are expected to be able to satisfy the rapid growth of today's capacity demand. However, the transparency of such networks makes them highly vulnerable to deliberate attacks, specifically targeting the physical layer. Physical-layer attacks, such as high-power jamming, can cause severe service disruption or even service denial, enhanced by their capability to propagate through a transparent optical network. Several attack-aware routing and wavelength assignment algorithms have been proposed to reduce the possible disruption caused by high-power jamming attacks. However, even with network planning approaches which take network security, specifically physical-layer attacks, into account, resilience to deliberate attacks in such scenarios remains an issue. In this paper, we propose the use of wavelength-selective attenuators as power equalizers inside network nodes to limit the propagation of high-power jamming attacks. Due to the increased cost of optical switching nodes associated with the addition of power equalizers, we aim at minimizing their number through sparse power equalization placement. We developed a set of greedy algorithms to solve what we call the Power Equalization Placement (PEP) problem with the objective of minimizing the number of power equalizers needed to reduce, to a desired level, the propagation of high-power jamming attacks for a given routing scheme. We further improved upon these results by proposing a GRASP (Greedy Randomized Adaptive Search Procedure) heuristic with a somewhat longer execution time, but with significantly superior results. The performance evaluation results indicate that the proposed GRASP heuristic can achieve the same attack propagation reduction as can be obtained by equipping all nodes with power equalizers by placing them at less than 50% of the nodes on average, potentially yielding significant cost savings.

  • 49.
    Jirattigalachote, Amornrat
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Katrinis, Kostas
    Tzanakaki, A.
    Impairment aware routing with service differentiation in heterogeneous WDM networks2009Inngår i: Network Architectures, Management, and Applications VII, SPIE - International Society for Optical Engineering, 2009, s. 763307-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In transparent Wavelength Division Multiplexing (WDM) networks, the signal is transported from source to destination in the optical domain through all-optical channels, or lightpaths. A lightpath may traverse several fiber segments and optical components that in general degrade the optical signal. This effect introduces the need for considering physical layer impairments during the connection-provisioning phase. Physical layer impairments can be divided into linear and non-linear. Both types of impairments are highly dependent on the fiber characteristics, which in turn are sensitive to length, temperature and age. A close look at the fiber infrastructure of today's network operators reveals a situation where old and newly deployed fibers coexist in the network. This heterogeneous fiber plant presents a challenge. A tradeoff should be found between the QoS requirements of connection requests and the use of the available (old and new) network resources. This calls for a provisioning mechanism able to adapt to the various fiber composition scenarios. In parallel, given the need for service differentiation, the authors recently proposed an Impairment Constraint Based Routing (ICBR) algorithm, referred to as ICBR-Diff, supporting differentiation of services at the BER (Bit Error Rate) level in a network with a homogeneous fiber infrastructure. In this paper the ICBR-Diff algorithm is extended to heterogeneous network; particularly, it is evaluated in WDM networks with fiber links having varying Polarization Mode Dispersion characteristics, i.e., with old and new fiber coexisting. Simulation results show that the ICBR-Diff algorithm exhibits high adaptability in a heterogeneous fiber composition scenario. This translates into improved performance in terms of blocking probability, when compared to traditional impairment aware routing algorithms.

  • 50.
    Jirattigalachote, Amornrat
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik (Stängd 20120101), Fotonik (Stängd 20120101).
    Katrinis, Kostas
    Athens Information Technology.
    Tzanakaki, Anna
    Athens Information Technology.
    Impairment aware routing with service differentiation in heterogeneous WDM networks2009Inngår i: 2009 Asia Communications and Photonics Conference and Exhibition, ACP 2009, 2009, s. 1-2Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We evaluate an Impairment Constraint Based Routing algorithm with service differentiation (ICBR-Diff) applied in WDM networks with fiber links having varying Polarization Mode Dispersion characteristics. Simulation results show high adaptability of the ICBR-Diff approach to this heterogeneous fiber scenario when compared to conventional routing schemes.

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