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  • 201.
    Peroza Marval, Maria Jose
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Fumagalli, A.
    Adaptive routing based on summary information mitigates the adverse impact of outdated control messages2011In: Transparent Optical Networks (ICTON), 2011 13th International Conference on, Stockholm, 2011, p. 1-4Conference paper (Refereed)
    Abstract [en]

    Adaptive routing is considered as a promising solution to support flexible resource allocation in wavelength division multiplexing network. Resource advertisement protocols, such as link state advertisement (LSA), are essential to enable routing algorithms to efficiently carry out the required path computation. The LSA nonnegligible convergence time may lead to outdated link information, which in turns may adversely affect the efficiency of the computed path. As a result, traffic engineering is suboptimal and some services may be unnecessarily blocked. This study investigates the impact of outdated information on the blocking probability of adaptive routing schemes focusing on two LSA protocols: one advertising specific resource information and one advertising only a summary of the same. Our simulation results show that compared with the routing scheme requiring specific information LSA, the approach based on LSA with summary information is by its nature not precise and hence able to mitigate the adverse impact of the LSA convergence time on blocking performance.

  • 202. Pándi, Z.
    et al.
    Fumagalli, A.
    Tacca, M.
    Wosinska, Lena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Impact of OXC failures on network reliability2004In: Proc SPIE Int Soc Opt Eng, 2004, p. 139-150Conference paper (Refereed)
    Abstract [en]

    The paper studies the impact of OXC equipment failure in WDM networks with dynamic end-to-end optical circuit provisioning. At the OXC level, equipment reliability is calculated using proven component level reliability models. At the network level, end-to-end optical circuits are provisioned with various levels of reliability, thus offering differentiated reliability to applications. The desired reliability level is obtained via shared path protection (SPP) switching, that provides efficient resource utilization. A selection of representative OXC architectures is examined to assess the influence of various switching technologies on the overall network level reliability. The selected OXC architectures are compared in terms of both the cost of switching equipment and the ability of the network to accommodate incoming circuit requests, while satisfying their required reliability level.

  • 203. Raffaelli, C.
    et al.
    Tonini, F.
    Fiorani, Matteo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Furdek, Marija
    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.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Optimization of Centralized Radio access networks in indoor areas2016In: International Conference on Transparent Optical Networks, Institute of Electrical and Electronics Engineers (IEEE), 2016Conference paper (Refereed)
    Abstract [en]

    A Centralized Radio Architecture (CRA) allows for the coordination of the physical layer functions of macro and small cells. Efficient techniques can be introduced based on the CRA concept, but deployment cost could potentially increase if CRA networks are not carefully designed. This paper proposes a number of design strategies aimed at cost minimization for CRA networks in residential areas based on heuristics which easily scale with the number of indoor antennas. A few different algorithms, which aim at reducing the overall amount of equipment to cover the area, are described and compared.

  • 204. Raffaelli, C.
    et al.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Andriolli, N.
    Callegati, F.
    Castoldi, P.
    Kabacinski, W.
    Maier, G.
    Pattavina, A.
    Valcarenghi, L.
    Photonics in Switching in NoE e-Photon/One+2007In: ICTON 2007: Proceedings of the 9th International Conference on Transparent Optical Networks, Vol 1 / [ed] Marciniak, M, 2007, Vol. 1, p. 167-170Conference paper (Refereed)
    Abstract [en]

    The exploitation of photonic technology through application of switching principles and system concepts in switch implementation, i.e. photonics in switching, is a very challenging topic in the field of optical networking research. Many European research teams have been involved in high quality studies and trials in this field since several years and obtained funding opportunities for joining their expertise within the e-photon/One+ Network of Excellence. This talk aims at presenting how collaborations on photonics in switching research has been organized within e-Photon/One+ and which actions have been finalized for exploitation and dissemination of this knowledge in science and education. The paper will report a description of research contributions from different partners involved in photonics in switching research.

  • 205. Raffaelli, Carla
    et al.
    Vlachos, Kyriakos
    Andriolli, Nicola
    Apostolopoulos, Dimitrios
    Buron, Jakob
    van Caenegem, Ruth
    Danilewicz, Grzegorz
    Finochietto, Jorge M.
    Garcia-Haro, Joan
    Klonidis, Dimitrios
    O'Mahony, Mike
    Maier, Guido
    Pattavina, Achille
    Pavon-Marino, Pablo
    Ruepp, Sarah
    Savi, Michele
    Scaffardi, Mirco
    Tomkos, Ioannis
    Tzanakaki, Anna
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Zouraraki, Olga
    Neri, Fabio
    Photonics in switching: Architectures, systems and enabling technologies2008In: Computer Networks, ISSN 1389-1286, E-ISSN 1872-7069, Vol. 52, no 10, p. 1873-1890Article in journal (Refereed)
    Abstract [en]

    This paper describes recent research activities and results in the area of photonic switching carried out within the Virtual Department on Switching (VDS) of the European e-Photon/ONe Network of Excellence. Contributions from outstanding European research groups in this field are collected to offer a platform for future research in optical switching. The paper contains the main topics related to network scenarios, switch architectures and experiments, with an effort to investigate synergies and challenging opportunities for collaboration and integration of research expertise in the field.

  • 206. Rak, J.
    et al.
    Hutchison, D.
    Calle, E.
    Gomes, T.
    Gunkel, M.
    Smith, P.
    Tapolcai, J.
    Verbrugge, S.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    RECODIS: Resilient Communication Services Protecting End-user Applications from Disaster-based Failures2016In: International Conference on Transparent Optical Networks, IEEE Computer Society, 2016Conference paper (Refereed)
    Abstract [en]

    Disaster-based failures can seriously disrupt any communication network, making its services unavailable. Such disruptions may be caused by natural disasters, technology-related failures, or malicious attacks, and they are observably increasing in number, intensity and scale. When network services that are a part of critical infrastructure become unavailable, commercial and/or societal problems are inevitable. The issue of limiting the impact of disaster-based failures needs to be urgently addressed due to the lack of suitable mechanisms deployed in the current networks.

  • 207.
    Raza, Muhammad Rehan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Fiorani, Matteo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab). Kungliga Tekniska högskolan.
    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).
    Demonstration of Dynamic Resource Sharing Benefits in an Optical CRAN2016In: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 8, no 8, p. 621-632Article in journal (Other academic)
    Abstract [en]

    The next generation of mobilecommunication (i.e., 5G) will bring new challengesfor the transport infrastructure, e.g. in terms offlexibility and capacity. The joint orchestration ofradio and transport resources can help to addresssome of these challenges. One example is thepossibility to reconfigure the use of the transportnetwork resources according to the spatial andtemporal variations of the wireless traffic patterns.Using the concept of dynamic resource sharing, alimited pool of transport resources can be sharedamong a large number of radio base stations (RBSs)thus reducing considerably the overall deploymentcost of the transport infrastructure.This paper proposes a provisioning strategy for acentralized radio access network (C-RAN) with anoptical transport whose wavelength resources can bedynamically shared among multiple RBSs. Theproposed strategy utilizes a hierarchical softwaredefined networking (SDN) control plane where aglobal orchestrator optimizes the usage of radio andtransport resources. The benefits of the proposedstrategy are assessed both by simulation and byexperiment via an optical data plane emulatordeveloped for this purpose. It is shown that thedynamic resource sharing can save up to 31.4% oftransport resources compared to a conventionaldimensioning approach, i.e., based onoverprovisioning of wavelength resources.

  • 208.
    Raza, Muhammad Rehan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Fiorani, Matteo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Rostami, Ahmad
    Ericsson AB, Kista Sweden.
    Skubic, Björn
    Ericsson AB, Kista Sweden.
    Öhlen, Peter
    Ericsson AB, Kista Sweden.
    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).
    Dynamic Resource Sharing for C-RANs with Joint Orchestration of Radio and Transport2016In: ECOC 2016 42th European Conference on Optical Communication Proceedings, September 18 - 22, 2016, Düsseldorf, Germany, VDE Verlag GmbH, 2016, p. 1001-1003Conference paper (Refereed)
    Abstract [en]

    We present a resource allocation strategy for centralized radio access network architectures able to adapt to the wireless network capacity requirements. Both simulation and emulation results show that it is possible to reuse up to 33.3% of the transport resources.

  • 209.
    Raza, Muhammad Rehan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Fiorani, Matteo
    Ericsson AB, Kista Sweden.
    Rostami, Ahmad
    Ericsson AB, Kista Sweden.
    Öhlen, Peter
    Ericsson AB, Kista Sweden.
    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).
    Benefits of Programmability in 5G Transport Networks2017Conference paper (Refereed)
    Abstract [en]

    This paper shows how programmability can improve operators’ revenues and it presents a dynamic resource slicing policy that leads to more than one order of magnitude better resource utilization levels than convectional (static) allocation strategies.

  • 210.
    Raza, Muhammad Rehan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Fiorani, Matteo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Skubic, B
    Ericsson AB, Kista, Sweden.
    Mårtensson, J
    Acreo Swedish ICT AB, Kista, Sweden.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Power and Cost Modeling for 5G Transport Networks2015In: 2015 17th International Conference on Transparent Optical Networks (ICTON), Budapest, Hungary: IEEE Computer Society, 2015, article id 7193533Conference paper (Refereed)
    Abstract [en]

    Optical 5G transport networks are the subject of academic and industrial research aimed at identifying the best architectural and deployment options. In this regard, the optimization of both power consumption and equipment cost is a crucial aspect. This paper analyses a number of architectural options (i.e., all optical vs. intermediate electronic processing, with and without network caching) for optical 5G transport networks, with the objective of understanding which alternatives are the most promising in terms of total power consumption and equipment cost. The analysis presented in the paper shows that 10 Gbps transmission equipment combined with optical switching guarantees the best overall performance. On the other hand, 100 Gbps transmission equipment combined with electronic processing and network caching is also a promising approach, especially in fiber scarce scenarios.

  • 211.
    Raza, Muhammad Rehan
    et al.
    KTH.
    Natalino, Carlos
    KTH.
    Vidal, Allan
    Ericsson Research.
    Santos, Mateus
    Ericsson Research.
    Öhlen, Peter
    Ericsson Research.
    Wosinska, Lena
    KTH.
    Monti, Paolo
    KTH.
    Demonstration of Resource Orchestration Using Big Data Analytics for Dynamic Slicing in 5G Networks2018Conference paper (Refereed)
    Abstract [en]

    We present a proof-of-concept demonstration of an SDN/NFV-based orchestrator for sharing infrastructure resources among different tenants. The designed orchestrator maximizes the profit of an infrastructure provider by using a dynamic slicing approach based on big data analytics.

  • 212.
    Raza, Muhammad Rehan
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Natalino, Carlos
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Öhlen, Peter
    Ericsson Research.
    Wosinska, Lena
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    A Slice Admission Policy Based on Reinforcement Learning for a 5G Flexible RAN2018Conference paper (Refereed)
  • 213.
    Raza, Muhammad Rehan
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Rostaini, Ahmad
    Ericsson Res, S-16440 Kista, Sweden.;Corp Res Robert Bosch GmbH, D-70839 Gerlingen, Germany..
    Wosinska, Lena
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    A Slice Admission Policy Based on Big Data Analytics for Multi-Tenant 5G Networks2019In: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 37, no 7, p. 1690-1697Article in journal (Refereed)
    Abstract [en]

    Network slicing is a key concept in 5G networking. It enables an infrastructure provider (InP) to support heterogeneous services over a common platform by creating a customized slice for each one of them. Once in operation, the slices can be dynamically scaled up/down to match the variation of service requirements. Although an InP generates revenue by accepting a slice request, however it might need to pay a penalty (proportional to the level of service degradation) if a slice cannot be scaled up when required. Hence, it becomes crucial to decide which slice requests should be accepted in order to maximize the net profit of an InP. This paper presents a slice admission strategy based on big data analytics (BDA) predictions. The intuition is to accept a slice request only when it is estimated that no service degradation will take place for both the incoming slice request and the slices already in operation. In this way, the penalty paid by an InP is contained, with beneficial effects on the overall net profit. Apart from simulations, the performance of the proposed admission policy has also been evaluated using emulation. Simulation results show that, in the presence of a high penalty due to service degradation, using BDA predictions brings up to 50.7% increase in profit, as compared to a slice admission policy without BDA. Emulation results for a small network scenario show a profit increase of up to 383% with only a small impact on the slice provisioning time (i.e., due to the processing of BDA predictions).

  • 214.
    Raza, Muhammad Rehan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Rostami, Ahmad
    Vidal, Allan
    Santos, Mateus
    Wosinska, Lena
    KTH.
    Monti, Paolo
    KTH.
    Priority-Aware Service Orchestration Using Big Data Analytics for Dynamic Slicing in 5G Transport Networks2017In: 2017 European Conference on Optical Communication (ECOC), Institute of Electrical and Electronics Engineers (IEEE), 2017Conference paper (Refereed)
    Abstract [en]

    We demonstrate how to efficiently scale up/down resource slices allocated to tenants with different service priorities. Experimental results show that our proposed strategy - based on big data analytics - lowers service degradation by more than 51%, compared to priority unaware approaches.

  • 215.
    Raza, Muhammad Rehan
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Rostami, Ahmad
    Deutsche Bahn AG, Germany.
    Wosinska, Lena
    KTH, Superseded Departments (pre-2005), Microelectronics and Information Technology, IMIT.
    Monti, Paolo
    A Slice Admission Policy Based on Big Data Analytics for Multi-Tenant 5G NetworksIn: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213Article in journal (Refereed)
  • 216.
    Raza, Muhammad Rehan
    et al.
    KTH.
    Rostami, Ahmad
    Deutsche Bahn AG.
    Wosinska, Lena
    KTH.
    Monti, Paolo
    KTH.
    Resource Orchestration Meets Big Data Analytics: The Dynamic Slicing Use Case2018Conference paper (Refereed)
    Abstract [en]

    We present an orchestration policy based on big data analytics (BDA) to maximize the profit of infrastructure providers which dynamically slice their resources among different tenants. Results show that BDA can help to increase the profit by more than 49%.

  • 217. Regis, G. B.
    et al.
    Fonseca, K. V. O.
    Figueiredo, G. B.
    Monti, Paolo
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS.
    Wosinska, Lena
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS.
    De Santi, J.
    Differentiated Restoration Based Multipath Re-Provisioning for Disaster Recovery in EONs2018In: 2018 IEEE International Conference on Communications (ICC), Institute of Electrical and Electronics Engineers (IEEE), 2018, article id 8422784Conference paper (Refereed)
    Abstract [en]

    In this paper, we propose a new restoration algorithm for disaster recovery in Elastic Optical Networks (EONs). The algorithm considers the different requirements on restoration delay and bandwidth degradation while restoring over multiple routes. Furthermore, the algorithm is able to adapt the connection recover process to the post-disaster network conditions and, consequently, increase the number of restored connections. Results indicate that the proposed strategy is able to improve connections restorability and decrease bandwidth blocking probability when compared to restoration approach based on bandwidth degradation and multipath recovery.

  • 218.
    Ribera, Carlos
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Cavdar, Cicek
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Yayimli, Ayşegül Gençata
    Istanbul Technical University, Department of Computer Engineering.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Multi layer energy-efficiency in IP over WDM networks2012In: 2012 Asia Communications And Photonics Conference (ACP), IEEE , 2012, Vol. 28, no 14, p. ATh2D.7-Conference paper (Refereed)
    Abstract [en]

    We propose an energy-aware Internet Protocol (IP) traffic routing strategy together with a virtual topology adaptation approach to save energy in the IP over WDM networks by following a dynamic daily traffic profile.

  • 219.
    Rosa, A. N. F.
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab). Federal University of Para, Brazil.
    Wiatr, Pawel
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Cavdar, Cicek
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Carvalho, S. V.
    Costa, J. C. W. A.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Statistical analysis of blocking probability and fragmentation based on Markov modeling of elastic spectrum allocation on fiber link2015In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 354, p. 362-373Article in journal (Refereed)
    Abstract [en]

    In Elastic Optical Network (EON), spectrum fragmentation refers to the existence of non-aligned, small-sized blocks of free subcarrier slots in the optical spectrum. Several metrics have been proposed in order to quantify a level of spectrum fragmentation. Approximation methods might be used for estimating average blocking probability and some fragmentation measures, but are so far unable to accurately evaluate the influence of different sizes of:connection requests and do not allow in-depth investigation of blocking events and their relation to fragmentation. The analytical study of the effect of fragmentation on requests' blocking probability is still under explored In this work, we introduce new definitions for blocking that differentiate between the reasons for the blocking events. We developed a framework based on Markov modeling to calculate steady-state probabilities for the different blocking events and to analyze fragmentation related problems in elastic optical links under dynamic traffic conditions. This framework can also be used for evaluation of different definitions of fragmentation in terms of their relation to the blocking probability. We investigate how different allocation request sizes contribute to fragmentation and blocking probability. Moreover, we show to which extend blocking events, due to insufficient amount of available resources, become inevitable and, compared to the amount of blocking events due to fragmented spectrum, we draw conclusions on the possible gains one cart achieve by system defragmentation. We also show how efficient spectrum allocation policies really are in reducing the part of fragmentation that in particular leads to actual blocking events. Simulation experiments are carried out showing good match with our analytical results for blocking probability in a small scale scenario. Simulated blocking probabilities for the different blocking events are provided for a larger scale elastic optical link.

  • 220. Rosa, Adriana
    et al.
    Cavdar, Cicek
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Carvalho, S.
    Costa, J.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Spectrum allocation policy modeling for elastic optical networks2012In: High Capacity Optical Networks and Enabling Technologies (HONET), 2012 9th International Conference on, IEEE , 2012, p. 242-246Conference paper (Refereed)
    Abstract [en]

    Today, optical transmission technologies are able to support 400Gbps over a single optical channel. However, this capacity cannot fit in the current fixed frequency grid optical spectrum. On the other hand, high rate optical channels have to co-exist with different ranges of line rates in order to serve heterogeneous bandwidth requests from variety of internet applications. Today's fixed rate and rigid frequency grid optical transmission systems cause over provisioning, where usually more spectral resources are provided than necessary.

  • 221. Ruffini, M.
    et al.
    Achouche, M.
    Arbelaez, A.
    Bonk, R.
    Di Giglio, A.
    Doran, N. J.
    Furdek, Marija
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Jensen, R.
    Montalvo, J.
    Parsons, N.
    Pfeiffer, T.
    Quesada, L.
    Raack, C.
    Rohde, H.
    Schiano, M.
    Talli, G.
    Townsend, P.
    Wessaly, R.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Yin, X.
    Payne, D. B.
    Access and metro network convergence for flexible end-to-end network design [invited]2017In: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 9, no 6, p. 524-535, article id 7947089Article in journal (Refereed)
    Abstract [en]

    This paper reports on the architectural, protocol, physical layer, and integrated testbed demonstrations carried out by the DISCUS FP7 consortium in the area of access-metro network convergence. Our architecture modeling results show the vast potential for cost and power savings that node consolidation can bring. The architecture, however, also recognizes the limits of long-reach transmission for low-latency 5G services and proposes ways to address such shortcomings in future projects. The testbed results, which have been conducted end-toend, across access-metro and core, and have targeted all the layers of the network from the application down to the physical layer, show the practical feasibility of the concepts proposed in the project.

  • 222. Ruffini, M
    et al.
    Payne, D B
    Doran, N J
    Achouche, M
    Parsons, N
    Pfeiffer, T
    Yin, X
    Rohde, H
    Schiano, M
    Ossieur, P
    O’Sullivan, B
    Wessäly, R
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Montalvo, J
    DISCUS: The Distributed Core For Ubiquitous Broadband Access2013In: Future Network and MobileSummit 2013, 2013Conference paper (Refereed)
    Abstract [en]

    A new end to end architecture based on Long-Reach Passive OpticalNetwork (LR-PON) with wireless integration, a distributed core built of opticaltransparency islands and an OpenFlow-based control plane, which is beingdeveloped in the EU project DISCUS, is described in this paper. The maintechnological advances and the network modelling and optimization approach arereported.

  • 223. Ruffini, M.
    et al.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Achouche, M.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Doran, N.
    Farjady, F.
    Montalvo, J.
    Ossieur, P.
    O’Sullivan, B.
    Parsons, N.
    Pfeiffer, T.
    Qiu, Xing-Zhi
    Raack, C.
    Rohde, H.
    Schiano, M.
    Townsend, P.
    Wessaly, R.
    Yin, Xin
    Payne, D. B.
    DISCUS: An End-to-End Solution for Ubiquitous Broadband Optical Access2014In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 52, no 2, p. S24-S32Article in journal (Refereed)
    Abstract [en]

    Fiber to the premises has promised to increase the capacity in telecommunications access networks for well over 30 years. While it is widely recognized that optical-fiber-based access networks will be a necessity in the shortto medium-term future, its large upfront cost and regulatory issues are pushing many operators to further postpone its deployment, while installing intermediate unambitious solutions such as fiber to the cabinet. Such high investment cost of both network access and core capacity upgrade often derives from poor planning strategies that do not consider the necessity to adequately modify the network architecture to fully exploit the cost benefit that a fiber-centric solution can bring. DISCUS is a European Framework 7 Integrated Project that, building on optical-centric solutions such as long-reach passive optical access and flat optical core, aims to deliver a cost-effective architecture for ubiquitous broadband services. DISCUS analyzes, designs, and demonstrates end-to-end architectures and technologies capable of saving cost and energy by reducing the number of electronic terminations in the network and sharing the deployment costs among a larger number of users compared to current fiber access systems. This article describes the network architecture and the supporting technologies behind DISCUS, giving an overview of the concepts and methodologies that will be used to deliver our end-to-end network solution.

  • 224. Ruffini, Marco
    et al.
    Doran, Nick
    Achouche, Mohand
    Parsons, Nick
    Pfeiffer, Thomas
    Yin, Xin
    Rohde, Harald
    Schiano, Marco
    Ossieur, Peter
    O’Sullivan, Barry
    Wessaly, Roland
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Montalvo, Julio
    Payne, David B.
    DISCUS: End-to-end network design for ubiquitous high speed broadband services2013In: Transparent Optical Networks (ICTON), 2013 15th International Conference on, 2013, p. 1-5Conference paper (Refereed)
    Abstract [en]

    Fibre-to-the-premises (FTTP) has been long sought as the ultimate solution to satisfy the demand for broadband access in the foreseeable future, and offer distance-independent data rate within access network reach. However, currently deployed FTTP networks have in most cases only replaced the transmission medium, without improving the overall architecture, resulting in deployments that are only cost efficient in densely populated areas (effectively increasing the digital divide). In addition, the large potential increase in access capacity cannot be matched by a similar increase in core capacity at competitive cost, effectively moving the bottleneck from access to core. DISCUS is a European Integrated Project that, building on optical-centric solutions such as Long-Reach Passive Optical access and flat optical core, aims to deliver a cost-effective architecture for ubiquitous broadband services. One of the key features of the project is the end-to-end approach, which promises to deliver a complete network design and a conclusive analysis of its economic viability.

  • 225.
    Ruiz, Marc
    et al.
    Universitat Politècnica de Catalunya.
    Velasco, Luis
    Universitat Politècnica de Catalunya.
    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).
    A Linearized Statistical XPM Model for Accurate Q-factor Computation2012In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 16, no 8, p. 1324-1327Article in journal (Refereed)
    Abstract [en]

    Non-linear physical layer impairments make the mathematical programming formulation of off-line impairment-aware (IA) Routing and Wavelength Assignment (RWA) problem to be non-linear. To alleviate that, this paper presents for the first time a statistical linear model to compute the Cross Phase Modulation (XPM) noise variance. Exhaustive evaluation reveals that the proposed linear model provides an accurate Q-factor estimation. An example of Integer Linear Programming (ILP) formulation integrating the XPM model is also given.

  • 226. Samadi, Payman
    et al.
    Fiorani, Matteo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Shen, Yiwen
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Bergman, Keren
    Flexible Architecture and Autonomous Control Plane for Metro-Scale Geographically Distributed Data Centers2017In: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 35, no 6, p. 1188-1196Article in journal (Refereed)
    Abstract [en]

    Enterprises and cloud providers are moving away from deployment of large-scale data centers and towards smallto mid-sized data centers because of their lower implementation and maintenance costs. An optical metro network is used to provide connectivity among these data centers. The optical network requires flexibility on bandwidth allocation and various levels of Quality of Service to support the new emerging applications and services including the ones enabled by 5G. As a result, next generation optical metro networks face complex control and management issues that needs to be resolved with automation. We present a converged inter/intra data center network architecture with an autonomous control plane for flexible bandwidth allocation. The architecture supports both single-rate and multi-rate data planes with two types of physical layer connections (Background and Dynamic) that provide connections with strict bandwidth and latency requirements. We demonstrate autonomous bandwidth steering between two data centers on our prototype. Leveraging a simulation platform, we show up to 5x lower transmission times and 25% less spectrum usage compared with the single-rate conventional non-converged networks. This is a significant improvement in the data center network performance and energy efficiency.

  • 227. Samadi, Payman
    et al.
    Fiorani, Matteo
    KTH, School of Information and Communication Technology (ICT).
    Shen, Yiwen
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Bergman, Keren
    Self-Adaptive, Multi-Rate Optical Network for Geographically Distributed Metro Data Centers2017In: 2017 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC), IEEE , 2017Conference paper (Refereed)
    Abstract [en]

    We propose a self-adaptive, multi-rate converged architecture and control-plane for metro-scale inter-data-center networks, enabling live autonomous bandwidth steering. Experimental and numerical evaluations demonstrate up to 5x and 25% improvements in transmission times and spectrum usage.

  • 228. Shahid, Arslan
    et al.
    Machuca, Carmen Mas
    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).
    Comparative Analysis of Protection Schemes for Fixed Mobile Converged Access Networks based on Hybrid PON2015In: 2015 CONFERENCE OF TELECOMMUNICATION, MEDIA AND INTERNET TECHNO-ECONOMICS PROCEEDINGS, 2015Conference paper (Refereed)
    Abstract [en]

    Optical access networks are evolving in order to increase the bandwidth offered to the end users. However, as the delivered bandwidth grows, the data losses due to failures also rise. Moreover, the importance of uninterrupted network access is also growing, which makes network reliability a crucial problem to address. Furthermore, today's access network telecom arena has become very competitive, which forces network operators to reduce costs in order to gain some benefits. Cost reduction in access networks has been shown to be possible by node consolidation and fixed mobile convergence, due to the use of a single access network with different types of user and longer reach. This paper proposes four different protection schemes for converged access network architecture, where hybrid passive optical network is deployed to provide high bandwidth to the end users. The comparison is done in three different types of areas (i.e., Dense Urban, Urban and Rural) with respect to various aspects including connection availability, power consumption, required components, additional fiber and failure impact factor.

  • 229. Skorin-Kapov, Nina
    et al.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    A New Approach to Optical Networks Security: Attack-Aware Routing and Wavelength Assignment2010In: IEEE/ACM Transactions on Networking, ISSN 1063-6692, E-ISSN 1558-2566, Vol. 18, no 3, p. 750-760Article in journal (Refereed)
    Abstract [en]

    Security issues and attack management in transparent wavelength division multiplexing (WDM) optical networks have become of prime importance to network operators due to the high data rates involved and the vulnerabilities associated with transparency. Deliberate physical-layer attacks, such as high-powered jamming, can seriously degrade network performance and must be dealt with efficiently. While most approaches are focused on the developing fast detection and reaction mechanisms triggered in case of an attack, we propose a novel approach to help deal with these issues in the network planning and provisioning process as a prevention mechanism. Namely, we propose to route lightpaths in such a way as to minimize the potential damage caused by various physical-layer attacks. We present a new objective criterion for the routing and wavelength assignment (RWA) problem, which we call the maximum Lightpath Attack Radius (maxLAR), and formulate the routing subproblem as an integer linear program (ILP). We test it on small networks to get an insight into its complexity and compare it to a formulation that minimizes congestion. Results indicate that our formulation achieves significantly better results for the maxLAR while obtaining near-optimal or optimal congestion in all cases. For larger networks, we propose a tabu search algorithm for attack-aware lightpath routing, in combination with an existing graph-coloring algorithm for wavelength assignment. Testing and comparing with existing approaches from literature indicate its superiority with respect to the maxLAR and average lightpath load, albeit at the expense of somewhat higher congestion. However, this is justified with the obtained improvement in network security.

  • 230.
    Skorin-Kapov, Nina
    et al.
    Zagreb University.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    A tabu search algorithm for attack-aware lightpath routing2008In: ICTON 2008: PROCEEDINGS OF 2008 10TH ANNIVERSARY INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS, VOL 3 / [ed] Marciniak, M, NEW YORK: IEEE , 2008, p. 42-45Conference paper (Other academic)
    Abstract [en]

    Attacks in Transparent Optical Networks present a serious security threat to Successful network operation due to the high data rates involved and the vulnerabilities associated with transparency. Typical physical layer attacks can involve injecting high-powered jamming signals on legitimate data channels to exploit Vulnerabilities in optical components Such as crosstalk in switches and fibers, and gain competition in amplifiers. To assure a certain quality of service in the network, we propose a novel approach which considers Such security threats during the network planning process. More specifically, we propose a tabu search heuristic aimed to perform lightpath routing in Such a way as to minimize the possible 'reachability' of a jamming attack with respect to gain competition and inter-channel crosstalk. In this way we limit the worst case scenario which can potentially be caused by such an attack. We tested the algorithm on the 14-node NSF network and compare with shortest path routing. The algorithm not only yields better attack protection, but reduces lightpath congestion and minimizes the upper bound on the number of wavelengths needed for wavelength assignment.

  • 231. Skorin-Kapov, Nina
    et al.
    Furdek, Marija
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Zsigmond, Szilard
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Physical-Layer Security in Evolving Optical Networks2016In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 54, no 8, p. 110-117Article in journal (Refereed)
    Abstract [en]

    We are witnessing the evolution of optical networks toward highly heterogeneous, flexible networks with a widening area of application. As the bandwidth and reliability performance requirements of mission-critical applications tighten, and the amount of carried data grows, issues related to optical network security are becoming increasingly important. Optical networks are vulnerable to several types of attacks at the physical layer, typically aimed at disrupting the service or gaining unauthorized access to carried data. Such security breaches can induce financial losses to clients or loss of privacy, or cause network-wide service disruption, possibly leading to huge data and revenue losses. Awareness of system weaknesses and possible attack methods is a prerequisite for designing effective network security solutions. As optical networks evolve, new and changing vulnerabilities must be identified and dealt with efficiently. To this end, this article provides a comprehensive overview of potential physical-layer attack scenarios in current and future optical networks. It then proposes a general security framework, outlining possible strategies for dealing with such attacks, meant to aid in the development of efficient provisioning, monitoring, protection, and restoration schemes in the context of optical-layer security.

  • 232. Skorin-Kapov, Nina
    et al.
    Jirattigalachote, Amonrat
    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).
    An integer linear programming formulation for power equalization placement to limit jamming attack propagation in transparent optical networks2014In: Security and Communication Networks, ISSN 1939-0114, E-ISSN 1939-0122, Vol. 7, no 12, p. 2463-2468Article in journal (Refereed)
    Abstract [en]

    Transparent optical networks can be highly vulnerable to various physical-layer attacks, such as high-power jamming, which can cause widespread service disruption and even service denial. The propagation of such attacks can be thwarted with wavelength-selective attenuators, referred to as power equalizers, installed at the network nodes. However, employing all nodes with power equalization functionality can lead to substantial costs. In previous work, we proposed a heuristic approach for sparse power equalization placement to limit jamming attack propagation cost-effectively. The approach provides suboptimal solutions quickly; however, it does not guarantee optimality. Because placement of such power equalization is a long-term planning problem affecting the capital expenditures of the network operator, solution quality is more critical than execution time. Thus, in this paper, we propose an integer linear programming formulation for the problem to guarantee optimality in terms of the number of power equalizers placed. Evaluation results show that our proposed integer linear programming formulation is able to solve moderately sized problems in reasonable time. These results also support the efficiency of our previously proposed heuristic by confirming its ability to find optimal solutions for the cases tested.

  • 233. Skubic, Björn
    et al.
    Chen, Biao
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101). Zhejiang University, China.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Ahmed, Jawwad
    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).
    Improved scheme for estimating T-CONT bandwidth demand in status reporting DBA for NG-PON2009In: Network Architectures, Management, and Applications VII, SPIE - International Society for Optical Engineering, 2009, p. 76330E-Conference paper (Refereed)
    Abstract [en]

    A scheme for estimating T-CONT bandwidth demand within dynamic bandwidth allocation (DBA) for next-generation passive optical network (NG-PON) is proposed and evaluated. Estimating T-CONT bandwidth demand is considered as a main challenge in gigabit-capable passive optical network (GPON) DBA. The proposed minimum guaranteed T-CONT content (MGTC) scheme allows for a more conservative estimate of bandwidth demand. It is shown that at high load significant improvements in delay, jitter and bandwidth utilization can be achieved with the proposed scheme. For light loads the conventional scheme shows better delay performance. However, this may be overcome by controlled overgranting in the MGTC scheme.

  • 234. Skubic, Björn
    et al.
    Chen, Biao
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Ahmed, Jawwad
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Improved scheme for estimating T-CONT bandwidth demand in status reporting DBA for NG-PON2009In: 2009 Asia Communications and Photonics Conference and Exhibition, ACP 2009, 2009, Vol. 2009-SupplementConference paper (Refereed)
    Abstract [en]

    A scheme for estimating T-CONT bandwidth demand within dynamic bandwidth allocation (DBA) for next-generation passive optical network (NG-PON) is proposed and evaluated. Estimating T-CONT bandwidth demand is considered as a main challenge in gigabit-capable passive optical network (GPON) DBA. The proposed minimum guaranteed T-CONT content (MGTC) scheme allows for a more conservative estimate of bandwidth demand. It is shown that at high load significant improvements in delay, jitter and bandwidth utilization can be achieved with the proposed scheme. For light loads the conventional scheme shows better delay performance. However, this may be overcome by controlled over-granting in the MGTC scheme.

  • 235. Skubic, Björn
    et al.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Ahmed, Jawwad
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Chen, Biao
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Mukherjee, Biswanath
    Dynamic Bandwidth Allocation for Long-Reach PON: Overcoming Performance Degradation2010In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 48, no 11, p. 100-108Article in journal (Refereed)
    Abstract [en]

    A passive optical network, with its inherent point to multi-point structure, allows for centralized placement of active equipment and possible extension of its boundary towards core networks. This property of the PON can be exploited for node consolidation where multiple central offices are replaced by a single one covering a larger service area. Such node consolidation is being particularly driven by the need for network operational cost saving, and is offering significant challenges to PONs. The degree of node consolidation that can be achieved is limited by the reach of conventional PON systems. In order to achieve a larger degree of node consolidation, an extension of the PON reach, beyond the conventional 20 km, is required. This article addresses the challenges of the dynamic bandwidth allocation, where increased reach results in a degradation of DBA performance and quality of service support. This degradation is a consequence of the increased propagation delay of the DBA messages exchanged between different PON elements. A potential solution to the performance degradation is the introduction of a multi-threaded DBA. In this article, we examine for both Gigabit PON and Ethernet PON, the extent to which DBA performance degradation can be reduced by exploiting multi-threading. It is found that for both standards, multi-threading, if done properly, can be used to mitigate the performance degradation due to the increased reach. To make bandwidth allocation efficient, new schemes for coordinating the multiple threads are required in long reach PON.

  • 236. Skubic, Björn
    et al.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Ahmed, Jawwad
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Mukherjee, Biswanath
    A Comparison of Dynamic Bandwidth Allocation for EPON, GPON, and Next-Generation TDM PON2009In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 47, no 3, p. S40-S48Article in journal (Refereed)
    Abstract [en]

    Dynamic bandwidth allocation in passive optical networks presents a key issue for providing efficient and fair utilization of the PON upstream bandwidth while supporting the QoS requirements of different traffic classes. In this article we compare the typical characteristics of DBA, such as bandwidth utilization, delay, and jitter at different traffic loads, within the two major standards for PONs, Ethernet PON and gigabit PON. A particular PON standard sets the framework for the operation of DBA and the limitations it faces. We illustrate these differences between EPON and GPON by means of simulations for the two standards. Moreover, we consider the evolution of both standards to their next-generation counterparts with the bit rate of 10 Gb/s and the implications to the DBA. A new simple GPON DBA algorithm is used to illustrate GPON performance. It is shown that the length of the polling cycle plays a crucial but different role for the operation of the DBA within the two standards. Moreover, only minor differences regarding DBA for current and next-generation PONs were found.

  • 237.
    Skubic, Björn
    et al.
    Ericsson Research, Ericsson AB, Stockholm, Sweden.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Chen, Biao
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Ahmed, Jawwad
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Dynamic bandwidth allocation in EPON and GPON2010In: Convergence of Mobile and Stationary Next-Generation Networks / [ed] Krzysztof Iniewski, John Wiley & Sons, 2010Chapter in book (Refereed)
  • 238.
    Tombaz, Sibel
    et al.
    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).
    Farias, Fabricio
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS. Federal University of Para.
    Fiorani, Matteo
    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).
    Zander, Jens
    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.
    Is backhaul becoming a bottleneck for green wireless access networks?2014In: 2014 IEEE International Conference on Communications, ICC 2014, IEEE , 2014, p. 4029-4035Conference paper (Refereed)
    Abstract [en]

    Mobile operators are facing an exponential traffic growth due to the proliferation of portable devices that require a high-capacity connectivity. This, in turn, leads to a tremendous increase of the energy consumption of wireless access networks. A promising solution to this problem is the concept of heterogeneous networks, which is based on the dense deployment of low-cost and low-power base stations, in addition to the traditional macro cells. However, in such a scenario the energy consumed by the backhaul, which aggregates the traffic from each base station towards the metro/core segment, becomes significant and may limit the advantages of heterogeneous network deployments. This paper aims at assessing the impact of backhaul on the energy consumption of wireless access networks, taking into consideration different data traffic requirements (i.e., from todays to 2020 traffic levels). Three backhaul architectures combining different technologies (i.e., copper, fiber, and microwave) are considered. Results show that backhaul can amount to up to 50% of the power consumption of a wireless access network. On the other hand, hybrid backhaul architectures that combines fiber and microwave performs relatively well in scenarios where the wireless network is characterized by a high small-base-stations penetration rate.

  • 239. Tonini, F.
    et al.
    Fiorani, Matteo
    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).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Raffaelli, C.
    Monti, P.
    Minimum Cost Deployment of Radio and Transport Resources in Centralized Radio Architectures2016In: 2016 INTERNATIONAL CONFERENCE ON COMPUTING, NETWORKING AND COMMUNICATIONS (ICNC), IEEE Computer Society, 2016Conference paper (Refereed)
    Abstract [en]

    The traffic in mobile access networks is increasing at an exponential rate, with the majority of this traffic being generated indoor. To cope with this trend, heterogeneous network (HetNet) architectures based on the centralized radio architecture (CRA) concept have been recently proposed. A CRA network is able to reach high wireless network performance by centralizing the radio physical layer functions of macro and small cells. On the other hand, a CRA network puts strict latency and capacity requirements on the transport segment, which usually comprises a mixture of fiber- and copper-based infrastructure. These strict constraints may translate into high deployment costs if not carefully addressed. This paper proposes an optimized deployment strategy for CRA networks in residential areas. The objective of the proposed strategy is to contain the total deployment cost by minimizing the number of wireless and transport resources required. We demonstrate that our deployment strategy allows for a significant reduction of the required amount of network components and the overall network cost compared to the existing deployment solutions.

  • 240. Tonini, Federico
    et al.
    Fiorani, Matteo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS. Ericsson Res, Sweden.
    Furdek, Marija
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Raffaelli, Carla
    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).
    Radio and Transport Planning of Centralized Radio Architectures in 5G Indoor Scenarios2017In: IEEE Journal on Selected Areas in Communications, ISSN 0733-8716, E-ISSN 1558-0008, Vol. 35, no 8, p. 1837-1848Article in journal (Refereed)
    Abstract [en]

    Providing high capacity to the end users is one of the main challenges for the fifth generation (5G) of mobile networks. The users' habit to consume online contents indoor makes the outdoor-to-indoor capacity provisioning impractical, especially when the high-frequency bands proposed for 5G are employed. The centralized radio architecture (CRA) is an inbuilding solution, which relies on the centralization of baseband processing functions, fully or partly allowing for centralized cell management while providing signals directly inside the buildings. On the other hand, the massive deployment of CRAs in urban areas may yield to unacceptably high installation costs, due to the radio network equipment to be activated. To make CRAs appealing to mobile operators, we propose different deployment strategies to minimize the CRA deployment cost. We define the remote radio unit placement (RRUP) problem and formulate it as an integer linear program, obtaining optimal deployment solutions in small urban residential scenarios. We prove the RRUP problem to be NP-hard, requiring heuristic approaches to solve large problem instances. To this end, we propose an effective and scalable heuristic for minimizing the amount of radio equipment required to deploy CRAs in large urban areas.

  • 241. Tremblay, C.
    et al.
    Archambault, E.
    Bélanger, M. P.
    Littlewood, P.
    Clelland, W.
    Furdek, Marija
    KTH.
    Wosinska, Lena
    KTH.
    Agile optical networking: Beyond filtered solutions2018In: Optics InfoBase Conference Papers, Optics Info Base, Optical Society of America, 2018Conference paper (Refereed)
    Abstract [en]

    Filterless optical networks based on broadcast-and-select nodes and coherent transceivers are attractive cost-effective and flexible solutions in core networks. In this paper, we explore the suitability of filterless architectures in metropolitan core and aggregation networks.

  • 242.
    Tremblay, Christine
    et al.
    Ecole Technol Super, Network Technol Lab, Montreal, PQ, Canada..
    Archambault, Emile
    Ecole Technol Super, Network Technol Lab, Montreal, PQ, Canada..
    Belanger, Michel P.
    Ciena Corp, Ottawa, ON, Canada..
    Littlewood, Paul
    Ciena Corp, Ottawa, ON, Canada..
    Clelland, William
    Ciena Corp, Ottawa, ON, Canada..
    Furdek, Marija
    KTH.
    Wosinska, Lena
    KTH.
    Agile Optical Networking: Beyond Filtered Solutions2018In: 2018 Optical Fiber Communications Conference and Exposition, OFC 2018 - Proceedings, IEEE , 2018Conference paper (Refereed)
    Abstract [en]

    Filterless optical networks based on broadcast-and-select nodes and coherent transceivers are attractive cost-effective and flexible solutions in core networks. In this paper, we explore the suitability of filterless architectures in metropolitan core and aggregation networks.

  • 243. Tremblay, Christine
    et al.
    Xu, Zhenyu
    Archambault, Emile
    Mantelet, Guillaume
    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).
    Belanger, Michel P.
    Littlewood, Paul
    Proposed filterless architecture and control plane for emerging flexible coherent networks2013In: ICTON 2013: 15th International Conference on Transparent Optical Networks, 2013, p. 1-1Conference paper (Refereed)
    Abstract [en]

    Recent developments in coherent modem performance and digital signal processing (DSP) technologies have opened the opportunity for new agile network architectures [1, 2]. The filterless network concept has been proposed in [3] and it is shown that they are more cost-effective and reliable compared to active optical switching networks. Filterless optical networks use broadcast-and-select techniques in which passive non-filtered optical splitters and combiners are used for channel add-drop and fiber link interconnection. Furthermore, DSP-based coherent modems are complementary foundational technologies for flexible optical networking owing to their properties of dynamic impairment compensation, performance monitoring and tuneability. The resulting network architecture makes an attractive candidate solution for flexible optical networking [4]. In this talk, we review the recent progress in filterless optical network design and control [5]ᅵ[7]. In the first part, filterless architectural solutions are proposed for different network topologies and compared to active photonic switching solutions. A cost and performance analysis of filterless network solutions with 1 + 1 optical layer protection is also presented. In the second part, we present a control plane for filterless optical networks and describe its main characteristics through a performance study. Our results show that passive filterless networks can be considered as a cost effective and simpler alternative to active optical switching networks whenever traffic loading is not approaching full network capacity.

  • 244.
    Tzanakaki, Anna
    et al.
    Athens Information Technology.
    Georgakilas, Kostas
    Athens Information Technology.
    Katrinis, Kostas
    Athens Information Technology.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Jirattigalachote, Amornrat
    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).
    Network performance improvement in survivable WDM networks considering physical layer constraints2009In: ICTON: 11th International Conference on Transparent Optical Networks, 2009, p. 1089-1092Conference paper (Other academic)
    Abstract [en]

    This paper focuses on survivable optical networks and studies in detail the network performance improvement that can be achieved when jointly considering network resilience and physical layer constraints. The protection scheme used is path-based shared protection known as backup multiplexing. In the proposed solution routing and wavelength assignment for both primary and protection paths are jointly performed considering their physical performance. Simulations comparing the proposed solution with alternative schemes aiming at maximising sharing of protection resources have shown substantial network performance improvement in terms of blocking probability reduction when jointly addressing resilience and physical layer performance requirements.

  • 245.
    Tzanakaki, Anna
    et al.
    Athens Information Technology.
    Katrinis, Kostas
    Athens Information Technology.
    Politi, Tanya
    University of Peloponnese.
    Stavdas, Alex
    University of Peloponnese.
    Pickavet, Mario
    Ghent University—IBBT.
    Van Daele, Peter
    Ghent University—IBBT.
    Simeonidou, Dimitra
    University of Essex.
    O’Mahony, Mike J.
    University of Essex.
    Aleksic, Slavisa
    Vienna University of Technology.
    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).
    Power considerations towards a sustainable Pan-European network2011In: 2011 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION (OFC/NFOEC) AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE, 2011, p. 1-3Conference paper (Refereed)
    Abstract [en]

    Energy savings are observed and quantified in the Pan-European network using transparent optical network technology. The network was dimensioned, using realistic traffic predictions of the optical networking roadmap of the European project BONE.

  • 246. Tzanakaki, Anna
    et al.
    Katrinis, Kostas
    Politi, Tanya
    Stavdas, Alexandros
    Pickavet, Mario
    Van Daele, Peter
    Simeonidou, Dimitra
    O'Mahony, Mike J.
    Aleksic, Slavisa
    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).
    Dimensioning the Future Pan-European Optical Network With Energy Efficiency Considerations2011In: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 3, no 4, p. 272-280Article in journal (Refereed)
    Abstract [en]

    This paper studies the overall energy consumption of a pan-European optical transport network for three different time periods: today and in five and ten years from now. In each time period the pan-European network was dimensioned using traffic predictions based on realistic data generated by the optical networking roadmap developed in the framework of the European project Building the Future Optical Network in Europe-BONE. A wavelength routed wavelength division multiplexed optical network based on either transparent or opaque node architectures was examined considering exclusively either 10 Gbit/s or 40 Gbit/s per channel data rates. The results manifest that transparent optical networking technologies are expected to provide significant energy savings of the order of 35% to 55%. It was also shown that the migration towards higher data rates, i.e., from 10 Gbit/s to 40 Gbit/s, is assisting in improving the overall energy efficiency of the network.

  • 247.
    Tzanakaki, Anna
    et al.
    Univ Athens, Athens 15772, Greece..
    Wosinska, Lena
    KTH.
    Schares, Laurent
    IBM Corp, Yorktown Hts, NY 10598 USA..
    Liu, Hong
    Google, Mountain View, CA 94043 USA..
    Simeonidou, Dimitra
    Univ Bristol, Bristol BS8 1TH, Avon, England..
    Special Issue on Optical Data Center Networks2018In: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 10, no 7, p. ODC1-ODC3Article in journal (Other academic)
    Abstract [en]

    To support the current trends in cloud, Internet of Things, 5G, etc., massive amounts of data need to be processed and stored with very different performance requirements in terms of capacity, granularity, delay, etc. These requirements drive the need for both mega-size data centers (DCs) and distributed micro DCs interconnected with high-speed communication links. This special issue focuses on the key role of optical networking in meeting these requirements through high-capacity, energy-efficient, and flexible connectivity, and presents recent advancements in DC architectures, network solutions, and optical technologies needed to interconnect computing and storage resources within and between DCs.

  • 248.
    Udalcovs, Aleksejs
    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).
    Bobrovs, V.
    Schatz, Richard
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Power efficiency of WDM networks using various modulation formats with spectral efficiency limited by linear crosstalk2014In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 318, p. 31-36Article in journal (Refereed)
    Abstract [en]

    Small channel spacing in WDM systems offers very good spectral efficiency, but may reduce the transparent optical reach because of interchannel crosstalk. In turn, an increase in the network power consumption can be expected, due to the need for signal regeneration. This paper explores the trade-off between spectral efficiency, transparent optical reach, and power consumption. The results confirm that using the most energy efficient transponder (i.e., in terms of W/bps) does not always guarantee the lowest overall network power consumption. This is especially true over long point-to-point distances (i.e., multiple transmission fiber spans) where, in order to ensure stringent quality of transmission levels together with high spectral efficiency, the optical signal needs to be regenerated many times.

  • 249. Udalcovs, Aleksejs
    et al.
    Monti, Paolo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Bobrovs, Vjaceslavs
    Schatz, Richard
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Ivanovs, Girts
    Spectral and energy efficiency considerations in mixed-line rate WDM networks with signal quality guarantee2013In: ICTON 2013: 15th International Conference on Transparent Optical Networks, 2013, p. 1-7Conference paper (Refereed)
    Abstract [en]

    Mixed-Line Rate (MLR) is a cost efficient solution to cope with the rapidly increasing and heterogeneous Internet traffic. In a MLR-based scenario wavelength channels are organized in groups (i.e., sub-bands), each of which consisting of channels operating at the same rate, e.g., it is possible to have on the same fiber link subbands operating at 10 Gbps, 40 Gbps, and 100 Gbps. In order to increase spectral efficiency one can reduce not only the channel spacing within a sub-band but also the frequency spacing between sub-bands operating at different rates, i.e., the sub-band spacing. On the other hand smaller sub-band spacing may: (i) negatively impact the transparent optical reach of wavelength channels due to the higher inter-channel crosstalk levels, and consequently (ii) increase the network power consumption because of the need of more signal regeneration. This paper aims at assessing the trade-off between spectral efficiency and the power consumption in a WDM transport network, when a certain quality of transmission needs to be guaranteed at the receiving node. This is accomplished by evaluating a number of spectral efficient MLR solutions, where the number of wavelength channels allocated to each sub-band is varied while keeping the required Bit Error Rate (BER) level at the receiving node fixed. Results show that the width of each sub-band plays a central role in determining the power consumption of an end-to-end connection.

  • 250.
    Udalcovs, Aleksejs
    et al.
    KTH.
    Schatz, Richard
    KTH, School of Engineering Sciences (SCI), Applied Physics, Photonics.
    Monti, Paolo
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS.
    Ozolins, Oskars
    KTH, School of Engineering Sciences (SCI), Applied Physics, Photonics.
    Pang, Xiaodan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Navarro, Julien R. G.
    KTH, School of Engineering Sciences (SCI).
    Kakkar, Aditya
    KTH, School of Engineering Sciences (SCI).
    Louchet, H.
    Popov, Sergei
    KTH, School of Engineering Sciences (SCI), Applied Physics, Photonics.
    Wosinska, Lena
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Jacobsen, Gunnar
    Quantifying spectral and energy efficiency limitations of WDM networks due to crosstalk in optical nodes2017In: Optics InfoBase Conference Papers, OSA - The Optical Society , 2017Conference paper (Refereed)
    Abstract [en]

    We demonstrate the significant impact of crosstalk between add and drop ports at optical nodes on energy-efficiency per Hertz in WDM networks employing 32/64 Gbd DP-16QAM transmission, especially when the isolation is reduced to 30dB.

234567 201 - 250 of 337
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