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  • 51.
    Cheng, Yuxin
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Lin, Rui
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    De Andrade, Marilet
    Ericsson Research, Sweden.
    Wosinska, Lena
    Department of Electrical Engineering, Chalmers University of Technology, Sweden.
    Chen, Jiajia
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Disaggregated Data Centers: Challenges and Tradeoffs2019In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896Article in journal (Other academic)
    Abstract [en]

    Resource utilization of modern data centers is significantly limited by the mismatch between the diversity of the resources required by running applications and the fixed amount of hardwired resources (e.g., number of central processing unit CPU cores, size of memory) in the server blades. In this regard, the concept of function disaggregation is introduced, where the integrated server blades containing all types of resources are replaced by the resource blades including only one specific function. Therefore, disaggregated data centers can offer high flexibility for resource allocation and hence their resource utilization can be largely improved. In addition, introducing function disaggregation simplifies the system upgrade, allowing for a quick adoption of new generation components in data centers. However, the communication between different resources faces severe problems in terms of latency and transmission bandwidth required. In particular,the CPU-memory interconnects in fully disaggregated data centers require ultra-low latency and ultra-high transmission bandwidth in order to prevent performance degradation for running applications. Optical fiber communication is a promising technique to offer high capacity and low latency, but it is still very challenging for the state-of-the-art optical transmission technologies to meet the requirements of the fully disaggregated data centers. In this paper, different levels of function disaggregation are investigated. For the fully disaggregated data centers, two architectural options are presented, where optical interconnects are necessary for CPU-memory communications. We review the state-of-the-art optical transmission technologies and carry out performance assessment when employing them to support function disaggregation in data centers. The results reveal that function disaggregation does improve the efficiency of resource usage in the data centers, although the bandwidth provided by the state-of-the-art optical transmission technologies is not always sufficient for the fully disaggregated data centers. It calls for research in optical transmission to fully utilize the advantages of function disaggregation in data centers.

  • 52. Chiaraviglio, L.
    et al.
    Wiatr, Paweł
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Lorincz, J.
    Idzikowski, F.
    Listanti, M.
    Impact of energy-efficient techniques on a device lifetime2014In: 2014 IEEE Online Conference on Green Communications, OnlineGreenComm 2014, IEEE conference proceedings, 2014Conference paper (Refereed)
    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.

  • 53. Chiaraviglio, Luca
    et al.
    Wiatr, Pawel
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Lorincz, Josip
    Idzikowski, Filip
    Listanti, Marco
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Is Green Networking Beneficial in Terms of Device Lifetime?2015In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 53, no 5, p. 232-240Article in journal (Refereed)
    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).

  • 54.
    Chincoli, Michele
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Valcarenghi, Luca
    Scuola Superiore Sant'Anna.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Investigating the Energy Savings of Cyclic Sleep with Service Guarantees in Long Reach PONs2012In: Asia Communications and Photonics Conference, ACP, 2012, p. ATh1D.3-Conference paper (Refereed)
    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.

  • 55.
    da Silva, Carlos Natalino
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Yayimli, Aysegul
    Istanbul University of Technology.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Furdek, Marija
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Assessing the effects of physical layer attacks on content accessibility and latency in optical CDNs2017In: 19th International Conference on Transparent Optical Networks (ICTON), Girona, Spain: IEEE conference proceedings, 2017, article id 8024993Conference paper (Refereed)
    Abstract [en]

    Content Delivery Networks (CDNs) are a major enabler of large-scale content distribution for Internet applications. Many of these applications require high bandwidth and low latency for a satisfactory user experience, e.g., cloud gaming, augmented reality, tactile Internet and vehicular communications. Replication is one of the most prominent solutions to meet the requirements of latency-sensitive applications. However, infrastructure disruptions can greatly degrade the performance of such applications, or even cease their proper execution. The extent of degradation can be exacerbated by malicious attackers that target the critical elements of the CDN physical infrastructure to disconnect or severely degrade services.

  • 56.
    da Silva, Carlos Natalino
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Yayimli, Aysegul
    Istanbul University of Technology.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Furdek, Marija
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Content Accessibility in Optical Cloud Networks Under Targeted Link Cuts2017In: 2017 21st International Conference on Optical Network Design and Modeling, ONDM 2017 - Conference Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2017, article id 7958546Conference paper (Refereed)
    Abstract [en]

    One of the key enablers of the digital society is a highly reliable information infrastructure that can ensure resiliency to a wide range of failures and attacks. In cloud networks, replicas of various content are located at geographically distributed data centers, thus inherently enhancing cloud network reliability through diversification and redundancy of user accessibility to the content. However, cloud networks rely on optical network infrastructure which can be a target of deliberate link cuts that may cause service disruption on a massive scale. This paper investigates the dependency between the extent of damage caused by link cuts and a particular replica placement solution, as a fundamental prerequisite of resilient cloud network design that lacks systematic theoretical quantification and understanding. To quantify the vulnerability of optical cloud networks based on anycast communication to targeted link cuts, we propose a new metric called Average Content Accessibility (ACA). Using this metric, we analyze the impact of the number and the placement of content replicas on cloud network resiliency and identify the best and the worst case scenarios for networks of different sizes and connectivity. We evaluate the efficiency of simultaneous and sequential targeted link cuts, the latter reassessing link criticality between subsequent cuts to maximize disruption. Comparison with Average Two-Terminal Reliability (A2TR), an existing robustness measure for unicast networks, shows great discrepancy in the vulnerability results, indicating the need for new measures tailored to anycast-based networks.

  • 57.
    De Andrade, Marilet
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Skubic, Björn
    Ahmed, Jawwad
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Enhanced IPACT: solving the over-granting problem in long-reach EPON2013In: Telecommunications Systems, ISSN 1018-4864, E-ISSN 1572-9451, Vol. 54, no 2, p. 137-146Article in journal (Refereed)
    Abstract [en]

    In this paper we address an issue referred to as "over-granting problem", which is inherent in the existing dynamic bandwidth allocation algorithms for Ethernet-based Passive Optical Networks (EPON), in particular when deployed for multi-threaded scheme in long-reach scenario. In order to solve this problem we design a scheme for the algorithm of Interleaved Polling with Adapted Cycle Time (IPACT) with the limited service discipline. We evaluate the proposed scheme through simulations for single-thread and double-thread cases and demonstrate that, the network performance can be significantly improved by our solution in terms of average delay, jitter, and throughput.

  • 58. De Andrade, Marilet
    et al.
    Kramer, Glen
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Sallent, Sebastia
    Mukherjee, Biswanath
    Evaluating Strategies for Evolution of Passive Optical Networks2011In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 49, no 7, p. 176-184Article in journal (Refereed)
    Abstract [en]

    Rapidly-increasing traffic demands will require the upgrade of optical access networks, namely deployed Passive Optical Networks (PONs), which may soon face capacity exhaustion. Such upgrade options must consider several technical and cost factors for evolution toward a shared multiple-channel PON using Wavelength-Division Multiplexing (WDM). WDM can facilitate the seamless upgrade of PONs, since capacity can be increased by adding new wavelength channels. We study the requirements for optimal migration toward higher bandwidth per user, and examine scenarios and cost-effective solutions for PON evolution.

  • 59. Di Giglio, A.
    et al.
    Schiano, M.
    Ruffini, M.
    Payne, D.
    Doran, N.
    Achouche, M.
    Jensen, R.
    O’Sullivan, B.
    Pfeiffer, T.
    Bonk, R.
    Rohde, H.
    Talli, G.
    Yin, X.
    Wessaly, R.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Montalvo, J.
    Towards the distributed core for ubiquitous superfast broadband optical access2014In: 2014 European Conference on Networks and Communications (EuCNC), 2014, p. 1-5Conference paper (Refereed)
    Abstract [en]

    In this paper, we describe recent architectural and technological advances of the end to end optical network architecture proposed by the DISCUS project (the DIStributed Core for unlimited bandwidth supply for all Users and Services). The two main targets of DISCUS are the principle of equivalence in the access and the reduction of optical-to-electronic conversions in the metro-core network. Technological advances and techno-economic evaluation of Long-Reach Passive Optical Networks (LR-PON), as well as the optimal metro-core node architecture and the required network control plane framework are reported. Network infrastructure sharing challenges are also discussed.

  • 60.
    Di Pascale, Emanuele
    et al.
    CTVR, Trinity College, Ireland .
    Payne, David B.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Ruffini, Marco
    Locality-Aware Peer-to-Peer Multimedia Delivery Over Next-Generation Optical Networks2014In: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 6, no 9, p. 782-792Article in journal (Refereed)
    Abstract [en]

    The increasing success of multimedia services poses a serious challenge to both network operators and service providers. Traditional copper-based access technologies are being replaced by fiber-to-the-X (FTTX) deployments in order to meet this increasing bandwidth demand of individual users. However, the growing traffic volume in the access segment may overload the existing aggregation part of the network, therefore creating a bandwidth bottleneck in the core. To address this problem the traffic should be kept as much as possible in the access network, taking advantage of the high-capacity fiber infrastructure. Since multimedia traffic is dominating the network, locality-aware approaches to video content distribution can represent a good solution. In this work, we propose and evaluate a network-managed, peer-to-peer based caching scheme for multimedia distribution. Our results show that such a system is able to reduce core traffic compared to the traditional content delivery network (CDN) based strategies, while at the same time decreasing the overall power consumption of the network and offering cost-saving opportunities for operators.

  • 61. Dixit, A.
    et al.
    Mahloo, Mozhgan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Lannoo, B.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Colle, D.
    Pickavet, M.
    Protection strategies for Next Generation Passive Optical Networks -22014In: 2014 International Conference on Optical Network Design and Modeling, 2014, p. 13-18Conference paper (Refereed)
    Abstract [en]

    Next Generation Passive Optical Networks-2 (NG-PON2) are being considered to upgrade the current PON technology to meet the ever increasing bandwidth requirements of the end users while optimizing the network operators’ investment. Reliability performance of NG-PON2 is very important due to the extended reach and, consequently, large number of served customers per PON segment. On the other hand, the use of more complex and hence more failure prone components than in the current PON systems may degrade reliability performance of the network. Thus designing reliable NG-PON2 architectures is of a paramount importance. Moreover, for appropriately evaluating network reliability performance, new models are required. For example, the commonly used reliability parameter, i.e., connection availability, defined as the percentage of time for which a connection remains operable, doesn’t reflect the network wide reliability performance. The network operators are often more concerned about a single failure affecting a large number of customers than many uncorrelated failures disconnecting fewer customers while leading to the same average failure time. With this view, we introduce a new parameter for reliability performance evaluation, referred to as the failure impact. In this paper, we propose several reliable architectures for two important NG-PON2 candidates: wavelength division multiplexed (WDM) PON and time and wavelength division multiplexed (TWDM) PON. Furthermore, we evaluate protection coverage, availability, failure impact and cost of the proposed schemes in order to identify the most efficient protection architecture.

  • 62.
    Dixit, Abhishek
    et al.
    Ghent Univ iMinds, Dept Informat Technol, Ghent, Belgium..
    Mahloo, Mozhgan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Lannoo, Bart
    Ghent Univ iMinds, Dept Informat Technol, Ghent, Belgium..
    Chen, Jiajia
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Colle, Didier
    Ghent Univ iMinds, Dept Informat Technol, Ghent, Belgium..
    Pickavet, Mario
    Ghent Univ iMinds, Dept Informat Technol, Ghent, Belgium..
    Protection strategies for Next Generation Passive Optical Networks-22014In: 2014 INTERNATIONAL CONFERENCE ON OPTICAL NETWORK DESIGN AND MODELING, IEEE , 2014, p. 13-18Conference paper (Refereed)
    Abstract [en]

    Next Generation Passive Optical Networks-2 (NGPON2) are being considered to upgrade the current PON technology to meet the ever increasing bandwidth requirements of the end users while optimizing the network operators' investment. Reliability performance of NG-PON2 is very important due to the extended reach and, consequently, large number of served customers per PON segment. On the other hand, the use of more complex and hence more failure prone components than in the current PON systems may degrade reliability performance of the network. Thus designing reliable NG-PON2 architectures is of a paramount importance. Moreover, for appropriately evaluating network reliability performance, new models are required. For example, the commonly used reliability parameter, i.e., connection availability, defined as the percentage of time for which a connection remains operable, doesn't reflect the network wide reliability performance. The network operators are often more concerned about a single failure affecting a large number of customers than many uncorrelated failures disconnecting fewer customers while leading to the same average failure time. With this view, we introduce a new parameter for reliability performance evaluation, referred to as the failure impact. In this paper, we propose several reliable architectures for two important NGPON2 candidates: wavelength division multiplexed (WDM) PON and time and wavelength division multiplexed (TWDM) PON. Furthermore, we evaluate protection coverage, availability, failure impact and cost of the proposed schemes in order to identify the most efficient protection architecture.

  • 63. Dlas, M. P. I.
    et al.
    Grigoreva, E.
    MacHuca, C. M.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT).
    Wong, E.
    Delay-Constrained Framework for Road Safety and Energy-Efficient Intelligent Transportation Systems2018In: 2017 European Conference on Optical Communication (ECOC), Institute of Electrical and Electronics Engineers (IEEE), 2018, p. 1-3Conference paper (Refereed)
    Abstract [en]

    We propose a novel approach that exploits a delay-constrained framework to meet stringent delay requirements and achieves energy-savings in Intelligent Transportation Systems (ITS). Analytical results show 40% energy-savings in a network that delivers delay-sensitive safety information over ITS.

  • 64. Dobrijevic, O.
    et al.
    Natalino, Carlos
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Furdek, Marija
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Hodzic, H.
    Dzanko, M.
    Wosinska, Lena
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Another price to pay: An availability analysis for SDN virtualization with network hypervisors2018In: Proceedings of 2018 10th International Workshop on Resilient Networks Design and Modeling, RNDM 2018, Institute of Electrical and Electronics Engineers Inc. , 2018Conference paper (Refereed)
    Abstract [en]

    Communication networks are embracing the software defined networking (SDN) paradigm. Its architectural shift assumes that a remote SDN controller (SDNC) in the control plane is responsible for configuring the underlying devices of the forwarding plane. In order to support flexibility-motivated network slicing, SDN-based networks employ another entity in the control plane, a network hypervisor (NH). This paper first discusses different protection strategies for the control plane with NHs and presents the corresponding availability models, which assume possible failures of links and nodes in the forwarding plane and the control plane. An analysis of these protection alternatives is then performed so as to compare average control plane availability, average path length for the control communication that traverses NH, and infrastructure resources required to support them. Our results confirm the intuition that the NH introduction generally results in a reduction of the control plane availability, which stresses the need for appropriate protection. However, the availability achieved by each of the considered strategies is impacted differently by the node availability and the link failure probability, thus calling for a careful selection that is based on the infrastructure features.

  • 65. Farias, Fabricio
    et al.
    Fiorani, Matteo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Tombaz, Sibel
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Mahloo, Mozhgan
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Costa, Joao C. W. A.
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Cost- and energy-efficient backhaul options for heterogeneous mobile network deployments2016In: Photonic network communications, ISSN 1387-974X, E-ISSN 1572-8188, Vol. 32, no 3, p. 422-437Article in journal (Refereed)
    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.

  • 66. Farias, Fabricio S.
    et al.
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Västberg, Anders
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Nilsson, Mats
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS. KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Costa, J. C. W. A.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Green backhauling for heterogeneous mobile access networks: What are the challenges?2013In: 2013 9th International Conference on Information, Communications and Signal Processing (ICICS), IEEE Computer Society, 2013, p. 6782868-Conference paper (Refereed)
    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.

  • 67. Fiammengo, Martina
    et al.
    Lindström, Alexander
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Skubic, Björn
    Experimental evaluation of cyclic sleep with adaptable sleep period length for PON2011In: European Conference on Optical Communication, ECOC, Geneva, 2011Conference paper (Refereed)
    Abstract [en]

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

  • 68.
    Fiorani, M.
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Samadi, P.
    Shen, Y.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Bergman, K.
    KTH, School of Information and Communication Technology (ICT).
    Flexible architecture and control strategy for metro-scale networking of geographically distributed data centers2016In: European Conference on Optical Communication, ECOC, Institute of Electrical and Electronics Engineers Inc. , 2016, p. 166-168Conference paper (Refereed)
    Abstract [en]

    This paper proposes a flexible architecture and control strategy to enable adaptive resource allocation in metro-scale inter data center networks. Experimental implementation and numerical evaluations are presented, proving substantial benefits in terms of transmission time and resource usage. 

  • 69.
    Fiorani, Matteo
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Aleksic, Slavisa
    Casoni, Maurizio
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Energy-Efficient Elastic Optical Interconnect Architecture for Data Centers2014In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 18, no 9, p. 1531-1534Article in journal (Refereed)
    Abstract [en]

    To address the urgent need for high-capacity, scalable and energy-efficient data center solutions, we propose a novel data center network architecture realized by combining broadcast-and-select approach with elastic channel spacing technology. We demonstrate that the proposed architecture is able to scale efficiently with the number of servers and offers lower energy consumption at a competitive cost compared to the existing solutions.

  • 70. Fiorani, Matteo
    et al.
    Aleksic, Slavisa
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Casoni, Maurizio
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Energy Efficiency of an Integrated Intra-Data-Center and Core Network With Edge Caching2014In: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 6, no 4, p. 421-432Article in journal (Refereed)
    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.

  • 71.
    Fiorani, Matteo
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Optical networks for energy-efficient data centers2014Conference paper (Refereed)
    Abstract [en]

    The growing popularity of cloud and multimedia services is increasing the traffic volume that each datacenter (DC) needs to handle. As a consequence, the serious bottlenecks in DC networks in terms of both capacity and energy consumption need to be addressed. DC networks typically consist of edge tier, aggregation tier and core tier, which interconnect different servers within a DC as well as provide the interfaces to the Internet. Current large-scale DC network architectures are based on the fat-tree three-tiers topology [1] and on electronic switches, which are not able to scale to meet future traffic requirements in a sustainable manner. Reducing the power required by the inter- and intra-rack communication inside DCs through use of optical technology opens a way to solve this problem. However, the current optical switching technologies are not able to support the dynamic DC traffic, and hence, new optical interconnect architectures are needed. Several optical switching architectures have been recently proposed to replace the aggregation and core tiers of current DC networks with a high-capacity optical switch [1][2]. However, the largest amount of energy in current DC networks is consumed in the edge tier by the electronic top-of-the-rack (ToR) switches. Therefore, the optical switching in the aggregation-core tier doesn’t solve the problem. Moreover, the majority of the optical DC network architectures proposed so far can be categorized as optical circuit switching or optical packet switching. Unfortunately, there are certain limitations associated with these optical switching technologies for their application in DC networks. Namely, optical circuit switching architectures are not able handle the bursty and highly variable DC traffic while optical packet switching usually makes use of electronic buffers, which limit scalability and increase energy consumption. To reduce the energy consumption in the edge tier, we propose a novel optical broadcast-and-select - rchitecture at the ToR. In this architecture, each server is equipped with an optical network interface (ONI) and is connected to the other servers in the same rack through a N?2 coupler, where N represents the number of servers in the rack. In addition, in order to provide both fine switching granularity and high scalability, we propose the use of the elastic optical networking paradigm [3]. Consequently, each ONI will be equipped with a bandwidth variable transceiver (BVT), which provides the ability to tune wavelength and change dynamically the number of the occupied spectral slots. In this way, the capacity can be varied from 1 Gb/s to 100 Gb/s and beyond on a per-server level. On the other side, the inter-rack communications are handled by a large singlesided optical core switch. One of the commercially available single-sided switches is fabricated using the beam steering technology [4], where the maximum number of switch ports available so far is 192 and a 500-port matrix is under development. Larger single-sided switches can be realized by combining several stages of smaller switch matrices. The results of a preliminary study show that the proposed architecture is able to significantly reduce the energy consumption with respect to other solutions [1][2].

  • 72.
    Fiorani, Matteo
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Skubic, B.
    Martensson, J.
    Valcarenghi, L.
    Castoldi, P.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Challenges for 5G transport networks2014In: 2014 IEEE International Conference on Advanced Networks and Telecommunication Systems, ANTS 2014, IEEE conference proceedings, 2014Conference paper (Refereed)
    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.

  • 73.
    Fiorani, Matteo
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab). Kungliga Tekniska högskolan.
    Rostami, Ahmad
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Abstraction Models for Optical 5G Transport Networks2016In: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 8, no 9, p. 656-665Article in journal (Refereed)
    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.

  • 74.
    Fiorani, Matteo
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Rostami, Ahmad
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Transport Abstraction Models for an SDN-Controlled Centralized RAN2015In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 19, no 8, p. 1406-1409Article in journal (Refereed)
    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.

  • 75.
    Fiorani, Matteo
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Tombaz, S.
    Mårtensson, J.
    Skubic, Björn
    KTH, School of Information and Communication Technology (ICT).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Modeling energy performance of C-RAN with optical transport in 5G network scenarios2016In: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 8, no 11, article id B21Article in journal (Refereed)
    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).

  • 76.
    Fiorani, Matteo
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Tombaz, Sibel
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Farias, Fabricio S.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Monti, Paolo
    Joint Design of Radio and Transport for Green Residential Access Networks2016In: IEEE Journal on Selected Areas in Communications, ISSN 0733-8716, E-ISSN 1558-0008, Vol. 34, no 4, p. 812-822Article in journal (Refereed)
    Abstract [en]

    d Mobile networks are the largest contributor to the carbon footprint of the telecom sector and their contribution is expected to rapidly increase in the future due to the foreseen traffic growth. Therefore, there is an increasing urgency in the definition of green mobile network deployment strategies. This paper proposes a four-step design and power assessment methodology for mobile networks, taking into consideration both radio and transport segments. A number of mobile network deployment architectures for urban residential areas based on different radio (i.e., macro base station, distributed indoor radio, femto cell) and transport (i.e., microwave, copper, optical fiber) technologies are proposed and evaluated to identify the most energy efficient solution. The results show that with low traffic the conventional macro base station deployment with microwave based backhaul is the best option. However, with higher traffic values heterogeneous networks withmacro base stations and indoor small cells are more energy efficient. The best small cell solution highly depends on the transport network architecture. In particular, our results show that a femto cell based deployment with optical fiber backhaul is the most energy efficient, even if a distributed indoor radio architecture (DRA) deployment with fiber fronthaul is also a competitive approach.

  • 77.
    Fiorani, Matteo
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Tombaz, Sibel
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Casoni, Maurizio
    University of Modena and Reggio Emilia.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Green Backhauling for Rural Areas2014In: Green Backhauling for Rural Areas, IEEE , 2014Conference paper (Refereed)
    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.

  • 78.
    Fiorani, Matteo
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Tornatore, M.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Mukherjee, B.
    Optical spatial division multiplexing for ultra-high-capacity modular data centers2016In: 2016 Optical Fiber Communications Conference and Exhibition, OFC 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016Conference paper (Refereed)
    Abstract [en]

    We propose and evaluate four optical interconnect architectures based on spatial division multiplexing for ultra-high capacity modular data centers. It is shown in which way the best option depends on the network load and size.

  • 79.
    Forchheimer, Robert
    et al.
    Linköpings Universitet.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    An optical overlay network concept for hard QoS requirements2009In: ICTON 2009: 11TH INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS, 2009, p. 1195-1198Conference paper (Other academic)
    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.

  • 80.
    Furdek, Maria
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Džanko, Matija
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Resilience of optical networks based on architecture on demand nodes2014Conference paper (Refereed)
  • 81.
    Furdek, Maria
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Skorin-Kapov, N
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Shared path protection under the risk of high power jamming2014In: 2014 19th European Conference on Networks and Optical Communications, NOC 2014, 2014, p. 23-28Conference paper (Refereed)
    Abstract [en]

    Transparent optical networks are sensitive to high-power jamming which can degrade legitimate user signals via out-of-band effects in optical fibers and amplifiers, and in-band crosstalk in optical switches. Jamming signals can be inserted in the network either deliberately as an attack, with the intention to deteriorate service, or accidentally, due to component miscon-figuration. This type of attack/failure can potentially propagate through the network causing high data and revenue losses, requiring tailored survivability approaches which take these harmful effects into consideration. Namely, conventional network survivability approaches which protect transmission in case of component faults might not provide adequate protection from jamming since the working and backup paths of a connection may both be within reach of the same jamming signal, even if they are link/node disjoint. Previously, we proposed the concept of an Attack Group (AG) of an all-optical connection (referred to as a lightpath), comprised of all other lightpaths which potentially can affect it in case they carry a high-power jamming signal. Furthermore, we developed a jamming attack-aware dedicated path protection algorithm which establishes AG-disjoint working and backup paths for each connection. Herein, we extend this work by proposing an approach for Jamming-Aware Shared Path Protection (JA-SPP) to achieve survivability in the presence of jamming signals in a more resource-efficient way. We formulate the JA-SPP problem as an Integer Linear Problem (ILP) to obtain optimal solutions for smaller network instances. Comparison with standard SPP for single component faults (without jamming-awareness) shows that JA-SPP obtains solutions which offer protection from high-power jamming, in addition to single component faults, while using the same amount of resources (in terms of link and wavelength usage) as the standard SPP.

  • 82.
    Furdek, Maria
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Skorin-Kapov, N.
    Zsigmond, S.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Vulnerabilities and security issues in optical networks2014In: Transparent Optical Networks (ICTON), 2014 16th International Conference on, IEEE conference proceedings, 2014, p. 1-4Conference paper (Refereed)
    Abstract [en]

    The paper provides a comprehensive overview of security issues in state-of-the-art optical networks. It identifies and describes the main vulnerabilities of today’s and future networks and outlines potential methods of attack which could exploit these vulnerabilities.

  • 83. Furdek, Marija
    et al.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Skorin-Kapov, Nina
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Compound attack-aware routing and wavelength assignment against power jamming2011In: Asia Communication and Photonics Conference and Exhibition (ACP 2011), 2011Conference paper (Refereed)
    Abstract [en]

    Transparent optical networks (TONs) are susceptible to deliberate physical-layer attacks, such as high-power jamming, which can take advantage of certain vulnerabilities of the network fundamental physical components. Combined with the high data rates employed in TONs and the difficulties of monitoring in the optical domain, these attacks can cause significant damage to the functioning of the network before reaction mechanisms are triggered, and call for new methods of increasing network security through careful network planning. In our previous work, we have considered adding attack-awareness as an objective in individual phases of the Routing and Wavelength Assignment (RWA) process. Here, we propose a new compound objective criterion for RWA, called the Maximum Attack Radius (maxAR), which is being minimized through both phases of RWA. We compare our algorithm with existing RWA approaches with different degrees of attack-awareness and show that it significantly decreases network vulnerability to high-power jamming attacks.

  • 84.
    Furdek, Marija
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Dzanko, M.
    Matanic, M.
    Boric, I.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Mikac, B.
    Multi-hour network provisioning utilizing function programmable ROADMs2015In: International Conference on Transparent Optical Networks, IEEE Computer Society, 2015, Vol. 2015, article id 7193722Conference paper (Refereed)
    Abstract [en]

    The study focuses on optimization of optical networks based on function programmable ROADMs implemented by Architecture on Demand (AoD) under a multi-hour traffic scenario. The objective is to minimize the cost and energy consumption by reducing the number of active modules inside the nodes, and to investigate the impact of network reconfiguration frequency to potential savings and lightpath availability. The results indicate that AoD nodes combined with tailored routing can reduce cost and increase availability with no traffic disruptions during transitions between periods.

  • 85.
    Furdek, Marija
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Dzanko, Matija
    Glavica, Patrik
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Can Architecture on Demand nodes with self-healing capabilities improve reliability of optical networks?2014In: Optics InfoBase Conference Papers, 2014Conference paper (Refereed)
    Abstract [en]

    Architecture on Demand (AoD) nodes enable bypass of unneeded node components and support self-healing of node failures. We analyze how AoD impacts network reliability and propose a novel survivable lightpath routing strategy for AoD-based networks.

  • 86.
    Furdek, Marija
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Dzanko, Matija
    Glavica, Patrik
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Mikac, Branko
    Amaya, Norberto
    Zervas, Georgios
    Simeonidou, Dimitra
    Efficient Optical Amplification in Self-Healing Synthetic ROADMs2014In: 2014 International Conference on Optical Network Design and Modeling, ONDM 2014, 2014, p. 150-155Conference paper (Refereed)
    Abstract [en]

    Optical backbone networks are carrying enormous amount of traffic and therefore, network reliability performance is extremely important to minimize the service interruption time and loss of data. Besides, increasing energy consumption of the ICT sector makes network energy efficiency gain a lot of attention. Reducing the usage of components in the network is a promising strategy to both make network more energy efficient and reliable as it allows N putting idle components into a power-saving, or sleep, mode and (ii) reusing them as redundancy for failure recovery. The new generation of synthetic reconfigurable optical add-drop multiplexers (ROADMs) implemented by Architecture on Demand (AoD) supports the above functionalities by offering unprecedented flexibility and self-healing capabilities. In AoD nodes, components are interconnected via high-port-count optical switch serving as optical backplane, and each connection uses only the components necessary to fulfill the switching and processing requirements. In this paper, we aim at improving optical network availability and reducing power consumption by minimizing the number of optical amplifiers used in AoD nodes. To this end, a decision on the necessity of signal amplification is made for every connection according to the power level at each node. Unnecessary amplifiers are bypassed and put into sleep mode, decreasing the overall power consumption of the network This also reduces the associated risk of connection failure, while reuse of idle amplifiers for failure recovery further improves connection availability. To gain greater insight into the benefits of our approach, we analyze the performance of the NSF and EON network deploying AoD nodes with different optical backplane implementations, i.e. 3D MEMS and piezoelectric optical switch (POS), and compare them with networks deploying hard-wired ROADMs. Simulation results show that deployment of synthetic AoD nodes with POS as optical backplane can reduce the network mean down time and power consumption of EDFAs by up to 63% and 38%, respectively, on average over all test cases.

  • 87.
    Furdek, Marija
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Džanko, Matija
    Skorin-Kapov, Nina
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Planning of optical networks based on programmable ROADMs2015In: Asia Communications and Photonics Conference, ACPC 2015, 2015Conference paper (Refereed)
    Abstract [en]

    Synthetic programmable ROADMs enable great architectural flexibility and offer remarkable opportunities for network optimization. This paper summarizes the benefits and network planning challenges introduced by this technology and outlines optimization approaches to utilize its advantages. © 2015 OSA.

  • 88.
    Furdek, Marija
    et al.
    University of Zagreb, Croatia.
    Jirattigalachote, Amornrat
    KTH, School of Information and Communication Technology (ICT).
    Skorin-Kapov, Nina
    University of Zagreb, Croatia.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT).
    Attack-aware optical networks planning: A cost analysis2011In: 13th International Conference on Transparent Optical Networks, 2011. ICTON'11., IEEE , 2011Conference paper (Other academic)
    Abstract [en]

    Transparent optical networks (TONs) based on Wavelength Division Multiplexing (WDM) are the only viable future-proof solution for supporting rapidly growing traffic demands. In TONs, optical signals are propagated transparently between edge nodes without any O/E/O conversion. In this way, it is possible to reduce cost and energy consumption in the network, as well as obtain transparency to signal bit rates, modulation formats and protocols. However, the absence of O/E/O conversion makes it easier for erroneous signals to propagate through the network and affect existing traffic. This can be utilized to realize attacks exploiting the physical-layer characteristics of network elements. An example of such attacks is high-power jamming, where a high-powered signal is injected in the network aiming to deteriorate the signal quality on other, legitimate optical channels (referred to as lightpaths), as described in [1] and [2].

  • 89.
    Furdek, Marija
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Muhammad, Ajmal
    KTH, School of Information and Communication Technology (ICT).
    Zervas, Georgios
    Alloune, Nabih
    Tremblay, Christine
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Programmable Filterless Network Architecture Based on Optical White Boxes2016In: 20TH INTERNATIONAL CONFERENCE ON OPTICAL NETWORK DESIGN AND MODELING (ONDM 2016), IEEE conference proceedings, 2016Conference paper (Refereed)
    Abstract [en]

    We propose and evaluate a novel architecture enabling high-capacity, resource efficient and agile elastic optical networks. It is based on sliceable bandwidth-variable transponders and optical white box switches which route optical signals without filtering them. Instead of using active filtering components, each node is equipped with an optical white box based on a programmable optical switch that serves as an optical backplane. It provides interconnections between input/output ports and passive splitters and couplers. Due to signal broadcast and the absence of filtering (so-called drop-and-waste transmission), some of the signals appear on unintended links which can lead to an overhead in spectrum usage. To address this issue, we formulate the problem of signal routing, modulation format and spectrum assignment in programmable filterless networks based on optical white boxes as an integer linear program (ILP) with the objective to minimize the total spectrum usage. Simulation results indicate that our proposed solution obtains a beneficial tradeoff between component usage and spectrum consumption, using a drastically lower number of active switching elements than the conventional networks based on hard-wired reconfigurable add/drop multiplexers, and lowering the maximum used frequency slot by up to 48% compared to existing passive filterless networks.

  • 90.
    Furdek, Marija
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Muhammad, Ajmal
    KTH, School of Information and Communication Technology (ICT).
    Zervas, Georgios
    Tremblay, Christine
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Performance Evaluation of Programmable Filterless Networks Implemented by Optical White Boxes2016In: 2016 18TH INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS (ICTON), IEEE, 2016Conference paper (Refereed)
    Abstract [en]

    To support the immense traffic growth and enable scalable on-demand provisioning of service requests, optical networks must deliver great agility and reconfigurability in a cost-and resource-efficient manner. The progress in elastic coherent transmission [1] has enabled simplifications in the optical network architecture by, for example, replacing the costly wavelength switches in the add/drop part of colorless reconfigurable add/drop multiplexers (ROADMs) with passive couplers. The concept of passive filterless networking further proposes the elimination of wavelength switching in the transport function as well. It is based on completely passive interconnections realized by passive splitters and combiners, essentially forming fiber trees spanning the network nodes [2]. In such networks, transmission follows the Drop&Waste ( or Drop&Continue) scheme where each signal is broadcasted to all branches downstream of the source node in a tree, while a copy of signal continues to propagate downstream of the destination node [3]. Thus, the simplification of the nodal architecture comes at the expense of increased spectrum usage due to the presence of unfiltered signals. Moreover, the broadcasting of signals to inadvertent nodes raises confidentiality issues. An additional drawback stems from the inability of the passive, fixed interconnection of nodes to allow for topology reconfiguration. The optical white boxes, or programmable optical switches (also referred to as architecture-on-demand) can provide unparalleled switching and architectural flexibility [4]. Unlike in conventional ROADMs, optical modules (e.g., passive couplers, amplifiers or WSSs) inside an optical white box are not interconnected in a hard-wired manner, but are selected on demand by a reconfigurable optical backplane (OB), implemented by, e.g., a piezoelectric switch or 3D MEMs. An arbitrary nodal architecture can be configured by setting up the interconnections of the OB as per traffic requirements, and swiftly reconfigured to accommodate changing traffic demands, scale capacity, and ease migration and upgrade. Combining the agile filterless transmission with flexible optical white boxes into a programmable filterless network architecture, recently proposed in [5], integrates the agility of filterless operation with the high flexibility enabled by white boxes. The nodes in a programmable filterless network are equipped with a programmable OB hosting only passive couplers to route the connections. The preliminary study of routing, modulation format and spectrum assignment (RMSA) in programmable filterless networks aimed at spectrum usage minimization [5] shows that they are capable of reducing the amount of unfiltered signals compared to passive filterless networks and can significantly decrease spectrum usage. Due to the moderately-sized switches deployed for the OB, this architecture also offers the potential of diminishing the nodal costs compared to the conventional ROADM-based networks. In addition, when striving to minimize the spectrum usage, connections tend to get routed over fewer splitters as they are the cause of broadcasted, unfiltered signals. This may lead to a decrease in the total number and degree of passive couplers traversed by connections, which can reduce the signal losses and lower the amplification requirements. This talk will outline the operational principles of programmable filterless network architecture and their benefits in terms of spectrum and component usage. We will also present possible technological and optimization approaches to further enhance the performance of white box based filterless networks and the related preliminary results.

  • 91.
    Furdek, Marija
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Skorin-Kapov, Nina
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Attack-aware dedicated path protection in optical networks2016In: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 34, no 4, p. 1050-1061Article in journal (Refereed)
    Abstract [en]

    Due to the high data rates in optical networks,physical-layer attacks targeting service degradation, such as powerjamming, can potentially lead to large data and revenue losses.Conventional network survivability approaches which establishlink-disjoint working and backup paths to protect from componentfaults may not provide adequate protection for such attacks.Namely, the working and the backup paths, although link-disjoint,might both be affected by a single attack scenario due to specificattack propagation characteristics. To enhance the existing survivabilityapproaches, we utilize the concept of an attack group(AG) which incorporates these characteristics to identify connectionswhich can simultaneously be affected by a single attack. Weapply this concept to dedicated path protection (DPP) and developattack-aware DPP (AA-DPP) approaches which aim to establishAG-disjoint primary and backup paths in a cost-effective manner.We provide a two-step ILP formulation for the routing and wavelengthassignment of the working and backup paths, as well as aheuristic for larger problem instances. Numerical results indicatethat the proposed approaches provide dedicated path protectionschemes with enhanced attack protection without using more resources(i.e., wavelengths, average path lengths) than standardDPPmethods.

  • 92.
    Furdek, Marija
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Goscien, Roza
    Manousakis, Konstantinos
    Aibin, Michal
    Walkowiak, Krzysztof
    Ristov, Sashko
    Gushev, Marjan
    Marzo, Jose L.
    An overview of security challenges in communication networks2016In: PROCEEDINGS OF 2016 8TH INTERNATIONAL WORKSHOP ON RESILIENT NETWORKS DESIGN AND MODELING (RNDM), IEEE, 2016, p. 43-50Conference paper (Refereed)
    Abstract [en]

    The ongoing transition towards a networked society requires reliable and secure network infrastructure and services. As networks evolve from simple point to point systems towards complex, software-defined, ultra-high capacity and reach, and distributed cloud environments, new security challenges emerge. The EU-funded RECODIS project aims at coordinating and fostering research collaboration in Europe on disaster resiliency in communication networks. One of the disaster types, considered by RECODIS Working Group (WG) 4, are deliberate human-made attacks aimed at gaining unauthorized access to the network or disrupting the service. In order to develop methods for increasing network security in the presence of attacks, it is crucial to first identify the security vulnerabilities and attack methods that exploit them, as well as the capabilities and shortcomings of existing security schemes. To this end, the members of RECODIS WG4 performed a comprehensive overview of attack methods and security approaches from the literature. This overview covers the security vulnerabilities inherent to the underlying physical layer, the implications of software-defined networking to security, and security challenges in cloud networks spanning geographically distributed data centers.

  • 93. Goscien, R.
    et al.
    Natalino, Carlos
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Furdek, Marija
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Impact of high-power jamming attacks on SDM networks2018In: 22nd Conference on Optical Network Design and Modelling, ONDM 2018 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2018, p. 77-81Conference paper (Refereed)
    Abstract [en]

    Space Division Multiplexing (SDM) is a promising solution to provide ultra-high capacity optical network infrastructure for rapidly increasing traffic demands. Such network infrastructure can be a target of deliberate attacks that aim at disrupting a large number of vital services. This paper assesses the effects of high-power jamming attacks in SDM optical networks utilizing Multi-Core Fibers (MCFs), where the disruptive effect of the inserted jamming signals may spread among multiple cores due to increased Inter-Core CrossTalk (ICo-XT). We first assess the jamming-induced reduction of the signal reach for different bit rates and modulation formats. The obtained reach limitations are then used to derive the maximal traffic disruption at the network level. Results indicate that connections provisioned satisfying the normal operating conditions are highly vulnerable to these attacks, potentially leading to huge data losses at the network level.

  • 94. Grigoreva, Elena
    et al.
    Wong, Elaine
    Furdek, Marija
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Mas Machuca, Carmen
    Energy Consumption and Reliability Performance of Survivable Passive Optical Converged Networks: Public ITS Case Study2017In: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 9, no 4, p. C98-C107Article in journal (Refereed)
    Abstract [en]

    Access networks are evolving fast by increasing their capacity and coverage area, coping with a larger number of users and variety of terminals. Operators aim at keeping high network performance and quality of service but limiting their capital and operational expenditures by, e.g., minimizing investments and energy consumption using power saving at the network components. To address these challenges this paper evaluates the energy consumption, connection availability, and failure detection time of three protection schemes applicable for converged access networks: disjoint fiber protection, energy-efficient disjoint fiber protection, and reflective disjoint fiber protection. The schemes are assessed by a case study considering a public intelligent transport system (ITS). The studied ITS deploys a dedicated short-range communications radio access network connected to the service server through a protected passive access network. Comparison with unprotected architecture shows that reflective disjoint fiber protection offers low energy consumption and high connection availability, while it significantly reduces the failure detection time and, hence, the connection interruption time.

  • 95. Grover, W. D.
    et al.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101).
    Fumagalli, A.
    High availability in optical networks: Introduction to the feature issue2007In: Journal of Optical Networking, ISSN 1536-5379, Vol. 6, no 3, p. 319-321Article in journal (Refereed)
    Abstract [en]

    The Journal of Optical Networking's (JON) feature issue, focuses on architectures, technologies, and theory for achieving high service availability in optical transport networks. The feature accepted 14 submissions for publication, these works reflect some important directions and objectives in optical networking research. These papers can be categorized under three themes, cost considerations in survivable optical networks, optimization in survivability design including resource sharing schemes, availability guarantees, and capacity efficiency, protection in IP/MPLS over WDM. J. Farkas, A. Paradisi, and C. Antal, in their paper, proposes and experimentally validates a low-cost, robust, and scalable Ethernet-over-fiber network architecture with fast recovery from both node and link failures. The paper submitted by M. Scheffel proposes an interesting sort of template or building-block approach to constructing the end-to-end topology of a service path.

  • 96. Grover, Wayne
    et al.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS. KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Fumagalli, Andrea
    Call for Papers: High Availability in Optical Networks2006In: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 5, no 1, p. 75-76Article in journal (Other academic)
    Abstract [en]

    The Journal of Optical Networking (JON) is soliciting papers for a feature Issue pertaining to all aspects of reliable components and systems for optical networks and concepts, techniques, and experience leading to high availability of services provided by optical networks. Most nations now recognize that telecommunications in all its forms -- including voice, Internet, video, and so on -- are "critical infrastructure" for the society, commerce, government, and education. Yet all these services and applications are almost completely dependent on optical networks for their realization. "Always on" or apparently unbreakable communications connectivity is the expectation from most users and for some services is the actual requirement as well. Achieving the desired level of availability of services, and doing so with some elegance and efficiency, is a meritorious goal for current researchers. This requires development and use of high-reliability components and subsystems, but also concepts for active reconfiguration and capacity planning leading to high availability of service through unseen fast-acting survivability mechanisms. The feature issue is also intended to reflect some of the most important current directions and objectives in optical networking research, which include the aspects of integrated design and operation of multilevel survivability and realization of multiple Quality-of-Protection service classes. Dynamic survivable service provisioning, or batch re-provisioning is an important current theme, as well as methods that achieve high availability at far less investment in spare capacity than required by brute force service path duplication or 100% redundant rings, which is still the surprisingly prevalent practice. Papers of several types are envisioned in the feature issue, including outlook and forecasting types of treatments, optimization and analysis, new concepts for survivability, or papers on availability analysis methods or results. Customer, vendor, and researcher viewpoints and priorities will all be given consideration. Especially valuable to the community would be papers that include or provide measured data on actual reliability and availability performance of optical networking components or systems.Scope of SubmissionThe scope of the papers includes, but is not limited to, the following topics:

    • Reliability and availability measurement techniques specific to optical network devices or services.
    • Data on SRLG statistics and frequency of different actual failure causes.
    • Real-life accounts or data on failure and repair rates or projected values for use in availability analysis.
    • Availability analysis methods, especially for survivable networks with reconfigurable or adaptive failure-specific responses.
    • Availability analysis and comparisons of basic schemes for survivability.
    • Differentiated availability schemes.
    • Design for Multiple Quality of Protection.
    • Different schemes for on-demand survivable service provisioning.
    • Basic comparisons or proposals of new survivability mechanisms and architectures.
    • Concepts yielding higher than 1+1 protection switching availability at less than 100% redundancy.
    • Survivable service provisioning in domains of optical transparency: dealing with signal impairments.

    Manuscript Submission To submit to this special issue, follow the normal procedure for submission to JON, indicating "Feature Issue: Optical Network Availability" in the "Comments" field of the online submission form. For all other questions relating to this feature issue, please send an e-mail to jon@osa.org, subject line "Feature Issue: Optical Network Availability." Additional information can be found on the JON website: http://www.osa-jon.org/submission/.

  • 97. Grover, Wayne
    et al.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Fumagalli, Andrea
    Call for Papers: High Availability in Optical Networks2005In: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 4, no 12, p. 874-875Article in journal (Other academic)
    Abstract [en]

    The Journal of Optical Networking (JON) is soliciting papers for a feature Issue pertaining to all aspects of reliable components and systems for optical networks and concepts, techniques, and experience leading to high availability of services provided by optical networks. Most nations now recognize that telecommunications in all its forms -- including voice, Internet, video, and so on -- are "critical infrastructure" for the society, commerce, government, and education. Yet all these services and applications are almost completely dependent on optical networks for their realization. "Always on" or apparently unbreakable communications connectivity is the expectation from most users and for some services is the actual requirement as well. Achieving the desired level of availability of services, and doing so with some elegance and efficiency, is a meritorious goal for current researchers. This requires development and use of high-reliability components and subsystems, but also concepts for active reconfiguration and capacity planning leading to high availability of service through unseen fast-acting survivability mechanisms. The feature issue is also intended to reflect some of the most important current directions and objectives in optical networking research, which include the aspects of integrated design and operation of multilevel survivability and realization of multiple Quality-of-Protection service classes. Dynamic survivable service provisioning, or batch re-provisioning is an important current theme, as well as methods that achieve high availability at far less investment in spare capacity than required by brute force service path duplication or 100% redundant rings, which is still the surprisingly prevalent practice. Papers of several types are envisioned in the feature issue, including outlook and forecasting types of treatments, optimization and analysis, new concepts for survivability, or papers on availability analysis methods or results. Customer, vendor, and researcher viewpoints and priorities will all be given consideration. Especially valuable to the community would be papers that include or provide measured data on actual reliability and availability performance of optical networking components or systems.Scope of SubmissionThe scope of the papers includes, but is not limited to, the following topics:

    • Reliability and availability measurement techniques specific to optical network devices or services.
    • Data on SRLG statistics and frequency of different actual failure causes.
    • Real-life accounts or data on failure and repair rates or projected values for use in availability analysis.
    • Availability analysis methods, especially for survivable networks with reconfigurable or adaptive failure-specific responses.
    • Availability analysis and comparisons of basic schemes for survivability.
    • Differentiated availability schemes.
    • Design for Multiple Quality of Protection.
    • Different schemes for on-demand survivable service provisioning.
    • Basic comparisons or proposals of new survivability mechanisms and architectures.
    • Concepts yielding higher than 1+1 protection switching availability at less than 100% redundancy.
    • Survivable service provisioning in domains of optical transparency: dealing with signal impairments.

    Manuscript Submission To submit to this special issue, follow the normal procedure for submission to JON, indicating "Feature Issue: Optical Network Availability" in the "Comments" field of the online submission form. For all other questions relating to this feature issue, please send an e-mail to jon@osa.org, subject line "Feature Issue: Optical Network Availability." Additional information can be found on the JON website: http://www.osa-jon.org/submission/.

  • 98. Hasegawa, Hiroshi
    et al.
    Taniguchi, Y.
    Sato, K.
    Jirattigalachote, Amonrat
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Design strategies for survivable Grouped Routing Entity (GRE)-based optical networks2013In: Design of Reliable Communication Networks (DRCN), 2013 9th International Conference on the, 2013, p. 148-154Conference paper (Refereed)
    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.

  • 99. Ho, Pin-Han
    et al.
    Shen, Gangxiang
    Subramaniam, Suresh
    Mouftah, Hussein T.
    Qiao, Chunming
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Guest Editorial Energy-Efficiency in Optical Networks2014In: IEEE Journal on Selected Areas in Communications, ISSN 0733-8716, E-ISSN 1558-0008, Vol. 32, no 8, p. 1521-1523Article in journal (Other academic)
  • 100. Izquierdo-Zaragoza, J. -L
    et al.
    Furdek, Marija
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Nag, A.
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Pavon-Marino, P.
    On the dimensioning of survivable optical metro/core networks with dual-homed access2016In: IEEE International Conference on High Performance Switching and Routing, HPSR, IEEE Computer Society, 2016, article id 7483089Conference paper (Refereed)
    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.

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