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  • Analytical blocking probability model for hybrid immediate and advance reservations in optical WDM networks

     Triay Marques, Joan; Cervello Pastor, Cristina; Vokkarane, Vinod M.
    IEEE-ACM transactions on networking
    Date of publication: 2013
    Journal article

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    Immediate reservation (IR) and advance reservation (AR) are the two main reservation mechanisms currently implemented on large-scale scientific optical networks. They can be used to satisfy both provisioning delay and low blocking for delay-tolerant applications. Therefore, it seems reasonable that future optical network provisioning systems will provide both mechanisms in hybrid IR/AR scenarios. Nonetheless, such scenarios can increase the blocking of IR if no quality-of-service (QoS) policies are implemented. A solution could be to quantify such blocking performance based on the current network load and implement mechanisms that would act accordingly. However, current blocking analytical models are not able to deal with both IR and AR. In this paper, we propose an analytical model to compute the network-wide blocking performance of different IR/AR classes within the scope of a multiservice framework for optical wavelength-division multiplexing (WDM) networks. Specifically, we calculate the blocking on two common optical network scenarios using the fixed-point approximation analysis: on wavelength conversion capable and wavelength-continuity constrained networks. Performance results show that our model provides good accuracy compared to simulation results, even in a scenario with multiple reservation classes defined by different book-ahead times.

  • ID routing mechanism for opportunistic multi-hop networks

     Agusti Torra, Anna; Cervello Pastor, Cristina; Fiol Mora, Miquel Àngel
    IEEE communications letters
    Date of publication: 2013-12
    Journal article

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    This letter proposes a general packet delivery mechanism in which routing decisions are taken on the basis of the identifiers assigned to each node. Such identifiers depend on the position of each node in the network, and their purpose is to simplify as much as possible the communication process between each pair of nodes. The proposal is based on building trees as the Routing Protocol for Low-Power and Lossy Networks (RPL), described in RFC 6550, does. Then, each node of the tree receives a unique identifier following a hierarchical scheme. Hence, every two nodes of the tree can communicate with each other performing simple bitwise XOR operations at intermediate nodes instead of building, storing and maintaining complex routing tables.

  • On the optimal allocation of virtual resources in cloud computing networks

     Papagianni, Chrysa A.; Leivadeas, Aris; Papavassiliou, Symeon; Maglaris, Vasilis; Cervello Pastor, Cristina; Monje Hernandez, Alvaro
    IEEE transactions on computers
    Date of publication: 2013-06
    Journal article

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    Cloud computing builds upon advances on virtualization and distributed computing to support cost-efficient usage of computing resources, emphasizing on resource scalability and on demand services. Moving away from traditional data-center oriented models, distributed clouds extend over a loosely coupled federated substrate, offering enhanced communication and computational services to target end-users with quality of service (QoS) requirements, as dictated by the future Internet vision. Toward facilitating the efficient realization of such networked computing environments, computing and networking resources need to be jointly treated and optimized. This requires delivery of user-driven sets of virtual resources, dynamically allocated to actual substrate resources within networked clouds, creating the need to revisit resource mapping algorithms and tailor them to a composite virtual resource mapping problem. In this paper, toward providing a unified resource allocation framework for networked clouds, we first formulate the optimal networked cloud mapping problem as a mixed integer programming (MIP) problem, indicating objectives related to cost efficiency of the resource mapping procedure, while abiding by user requests for QoS-aware virtual resources. We subsequently propose a method for the efficient mapping of resource requests onto a shared substrate interconnecting various islands of computing resources, and adopt a heuristic methodology to address the problem. The efficiency of the proposed approach is illustrated in a simulation/emulation environment, that allows for a flexible, structured, and comparative performance evaluation. We conclude by outlining a proof-ofconcept realization of our proposed schema, mounted over the European future Internet test-bed FEDERICA, a resource virtualization platform augmented with network and computing facilities.

  • From delay-tolerant networks to vehicular delay-tolerant networks

     Rogerio Pereira, Paulo; Casaca, Augusto; Rodrigues, Joel J. P. C.; Soares, Vasco N. G. J.; Triay Marques, Joan; Cervello Pastor, Cristina
    IEEE Communications Surveys & Tutorials
    Date of publication: 2012
    Journal article

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  • Topology analysis of auto load-balancing RWA in optical burst-switched networks

     Triay Marques, Joan; Cervello Pastor, Cristina
    Wireless and Optical Communications Conference
    Presentation's date: 2011-04-15
    Presentation of work at congresses

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    With new optical transport systems able to provide sub-wavelength granularity, the dynamic characteristics of the network are expected to strongly increase. Furthermore, such properties are highly related to the underlying physical network topology, which in turn require from the control plane important features such as scalability, dynamism and automatism. In this paper we analyze the properties of a distributed routing and wavelength assignment (RWA) algorithm for wavelength continuity constraint optical networks which uses forwarding and updating control functions run by forward and backward control packets, respectively. In the paper, the protocol is evaluated through its implementation in optical burst switching (OBS) on four different transport network topologies. Results show that the protocol outperforms other RWA algorithms under test in terms of blocking probability without worsening other metrics such as end-to-end delay.

  • Dynamic service-aware reservation framework for multi-layer high-speed networks

     Triay Marques, Joan; Rousseau, Derek R.; Cervello Pastor, Cristina; Vokkarane, Vinod M.
    Workshop on Performance Modeling and Evaluation in Computer and Telecommunication Networks
    Presentation's date: 2011-08-04
    Presentation of work at congresses

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    Some current Internet applications (e.g., Grid/Cloud computing storage, video-conference) demand service differentiation, not only in terms of packet forwarding, but also at the connection level. To satisfy the demands for delay-sensitive and low-blocking applications, immediate reservation (IR) and advance reservation (AR) can be performed. Independent resource reservation of each type of network resources is well-investigated. Nevertheless, it is very likely that both types of requests will need to share network resources. There is also significant demand for a service framework that is able to provide applicationaware quality of service (QoS). By using existing scheduling algorithms for IR/AR, we develop a service framework to guarantee relative QoS among different application requests, with and without tolerance to delay and service blocking. Simulation results demonstrate the feasibility of our approach and provide a basis for future development of enhanced IR/AR QoS policies within the control plane of future high-speed networks.

  • Analytical model for hybrid immediate and advance reservation in optical WDM networks

     Triay Marques, Joan; Cervello Pastor, Cristina; Vokkarane, Vinod M.
    IEEE Global Communications Conference
    Presentation's date: 2011-12-07
    Presentation of work at congresses

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    Current Internet and large-scale experimentation applications need to satisfy short provisioning delay and low blocking demands. Both can be guaranteed by using immediate reservation (IR) and advance reservation (AR), respectively. However, the scheduling of both reservation types in the same network can especially degrade the performance of IR if no extra policies are applied. In order to enhance such class-based policies, we need to quantify the future performance of the system, thus requiring to model its behavior. In this paper, we propose the use of a two-fold probability transition Markov chain successfully applied in the past in offset-based reservation systems. Results show the good accuracy of the model to simulation results, even in an scenario with multiple traffic classes defined by different book-ahead times. Such a performance validates its applicability to a wide range of immediate and advance reservation systems.

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    Designing Messenger Visual, an instant messaging service for individuals with cognitive disability  Open access

     Tuset, Pere; López, Juan Miguel; Barberán, Pere; Janer, Léonard; Cervello Pastor, Cristina
    International Workshop on Ambient Assisted Living
    Presentation's date: 2011-06-08
    Presentation of work at congresses

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    Considering the importance of Internet-based communications in our society, the lack of Instant Messaging (IM) services adapted to individuals with cognitive disabilities who have difficulties using written language creates a situation of exclusion that has a negative impact on their daily lives. To alleviate this situation we present Messenger Visual, an IM service that uses pictograms as the main communication system. Along the paper we introduce the main design aspects of an IM service to support pictogram-based communications, as well as the design and evaluation aspects of an IM client that takes into account both the pictogram-based communication and the user interface accessibility requirements of individuals with cognitive disabilities.

  • Bundles fragmentation in vehicular delay-tolerant networks

     Magaia, N; Pereira, P. R.; Casaca, A.; Rodrigues, J.J.P.C.; Dias, J. A.; Isento, J. N.; Cervello Pastor, Cristina; Gallego Ezpeleta, J.
    Conference on Next Generation Internet Networks
    Presentation's date: 2011-06-28
    Presentation of work at congresses

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    Time shared optical network (TSON): A novel metro architecture for flexible multi-granular services  Open access

     Zervas, Georgios S.; Triay Marques, Joan; Amaya González, Norberto; Qin, Yixuan; Cervello Pastor, Cristina; Simeonidou, Dimitra
    European Conference and Exposition on Optical Communications
    Presentation's date: 2011-09-19
    Presentation of work at congresses

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    This paper presents the TSON metro mesh network architecture for guaranteed, statistically-multiplexed services. It proposes tunable time-wavelength assignment, one-way treebased reservation and node architecture. Results demonstrate high network efficiency, fast service delivery and guaranteed QoS.

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    GMPLS/PCE/OBST architectures for guaranteed sub-wavelength mesh metro network services  Open access

     Triay Marques, Joan; Zervas, Georgios S.; Cervello Pastor, Cristina; Simeonidou, Dimitra
    Optical Fiber Communication Conference and Exposition
    Presentation's date: 2011-03-10
    Presentation of work at congresses

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    This paper presents three innovative GMPLS/PCE/OBST interworking architectures for mesh metro networks which deliver guaranteed contention-free sub-wavelength services with enhanced channel utilization, yet enabling multi-technology interoperability.

  • Delay analysis of slotted OBS networks under DAOBS MAC protocol

     Triay Marques, Joan; Cervello Pastor, Cristina
    IEEE communications letters
    Date of publication: 2011-06-30
    Journal article

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    Medium access control (MAC) protocols can improve the burst/packet delivery rate in optical burst-switched (OBS) networks. In this letter, the delay analysis of slotted OBS under the use of the DAOBS MAC protocol is proposed. The correctness of the analysis has been assessed through simulation, showing that it achieves a good approximation on different networks despite the operational complexity of the protocol.

  • Performance analysis of the sent-but-sure strategy for optical burst and packet switched networks

     Agusti Torra, Anna; Cervello Pastor, Cristina; Fiol Mora, Miquel Àngel
    Performance evaluation
    Date of publication: 2011-01
    Journal article

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    This work proposes an analytical model to characterize the performance of a loss-free transmission strategy for Optical Burst and Packet Switched Networks, which ensures that a burst/packet will successfully reach its destination once it has been scheduled in the first link of its path. In this paper this strategy is called Sent-But-Sure (SBS) because it avoids losses in any intermediate node. The SBS strategy combines a routing and wavelength assignment scheme with simple contention resolution mechanisms. As a result, new burst/packet allocation attempts in an intermediate node only contend with bursts/packets in transit coming from a single input link. Moreover, bursts/packets in transit always have priority over bursts/packets whose transmission has not been scheduled yet. These two main features of the SBS strategy allow us to develop an analytical model based on a twopriority M/G/1 queueing model to characterize the network performance.

  • Enabling future internet research: the FEDERICA case

     Szegedi, P.; Riera, J. F.; Garcia-Espin, J. A.; Hidell, M.; Sjodin, P.; Soderman, P.; Ruffini, M.; O'Mahony, D.; Bianco, A.; Giraudo, L.; Ponce de Leon, M.; Power, G.; Cervello Pastor, Cristina; Lopez, V.; Naegele-Jackson, S.
    IEEE communications magazine
    Date of publication: 2011-07
    Journal article

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    The Internet, undoubtedly, is the most influential technical invention of the 20th century that affects and constantly changes all aspects of our day-to-day lives nowadays. Although it is hard to predict its long-term consequences, the potential future of the Internet definitely relies on future Internet research. Prior to every development and deployment project, an extensive and comprehensive research study must be performed in order to design, model, analyze, and evaluate all impacts of the new initiative on the existing environment. Taking the ever-growing size of the Internet and the increasing complexity of novel Internet-based applications and services into account, the evaluation and validation of new ideas cannot be effectively carried out over local test beds and small experimental networks. The gap which exists between the small-scale pilots in academic and research test beds and the realsize validations and actual deployments in production networks can be bridged by using virtual infrastructures. FEDERICA is one of the facilities, based on virtualization capabilities in both network and computing resources, which creates custom-made virtual environments and makes them available for Future Internet Researchers. This article provides a comprehensive overview of the state-of-the-art research projects that have been using the virtual infrastructure slices of FEDERICA in order to validate their research concepts, even when they are disruptive to the test bed’s infrastructure, to obtain results in realistic network environments.

  • Architectures and Protocols for Sub-Wavelength Optical Networks: Contributions to Connectionless and Connection-Oriented Data Transport  Open access

     Triay Marquès, Joan
    Defense's date: 2011-10-07
    Department of Telematics Engineering, Universitat Politècnica de Catalunya
    Theses

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    La ràpida evolució d’Internet i l’àmplia gamma de noves aplicacions (per exemple, multimèdia, videoconferència, jocs en línia, etc.) ha fomentat canvis revolucionaris en la manera com ens comuniquem. A més, algunes d’aquestes aplicacions demanden grans quantitats de recursos d’ample de banda amb diversos requeriments de qualitat de servei (QoS). El desenvolupament de la multiplexació per divisió de longitud d’ona (WDM) en els anys noranta va fer molt rendible la disponibilitat d’ample de banda. Avui dia, les tecnologies de commutació òptica de circuits són predominants en el nucli de la xarxa, les quals permeten la configuració de canals (lightpaths) a través de la xarxa. No obstant això, la granularitat d’aquests canals ocupa tota la longitud d’ona, el que fa que siguin ineficients per a proveir canals de menor ample de banda (sub-longitud d’ona). Segons la comunitat científica, és necessari augmentar la transparència dels protocols, així com millorar l’aprovisionament d’ample de banda de forma dinàmica. Per tal de fer això realitat, és necessari desenvolupar noves arquitectures. La commutació òptica de ràfegues i de paquets (OBS/OPS), són dues de les tecnologies proposades. Aquesta tesi contribueix amb tres arquitectures de xarxa destinades a millorar el transport de dades sub-longitud d’ona. En primer lloc, aprofundim en la naturalesa sense connexió en OBS. En aquest cas, la xarxa incrementa el seu dinamisme a causa de les transmissions a ràfega. A més, les col·lisions entre ràfegues degraden el rendiment de la xarxa fins i tot a càrregues molt baixes. Per fer front a aquestes col·lisions, es proposa un esquema de resolució de col·lisions pro actiu basat en un algorisme d’encaminament i assignació de longitud d’ona (RWA) que balanceja de forma automàtica i distribuïda la càrrega en la xarxa. En aquest protocol, el RWA i la transmissió de ràfegues es basen en l’explotació i exploració de regles de commutació que incorporen informació sobre contencions i encaminament. Per donar suport a aquesta arquitectura, s’utilitzen dos tipus de paquets de control per a l’encaminament de les ràfegues i l’actualització de les regles de commutació, respectivament. Per analitzar els beneficis del nou algorisme, s’utilitzen quatre topologies de xarxa diferents. Els resultats indiquen que el mètode proposat millora en diferents marges la resta d’algorismes RWA en funció de la topologia i sense penalitzar altres paràmetres com el retard extrem a extrem. La segona contribució proposa una arquitectura híbrida sense i orientada a connexió sobre la base d’un protocol de control d’accés al medi (MAC) per a xarxes OBS (DAOBS). El MAC ofereix dos mètodes d’accés: arbitratge de cua (QA) per a la transmissió de ràfegues sense connexió, i pre-arbitratge (PA) per serveis TDM orientats a connexió. Aquesta arquitectura permet una àmplia gamma d’aplicacions sensibles al retard i al bloqueig. Els resultats avaluats a través de simulacions mostren que en l’accés QA, les ràfegues de més alta prioritat tenen garantides zero pèrdues i latències d’accés molt baixes. Pel que fa a l’accés PA, es reporta que la duplicació de la càrrega TDM augmenta en més d’un ordre la probabilitat de bloqueig, però sense afectar en la mateixa mesura les ràfegues sense connexió. En aquest capítol també es tracten dos dels problemes relacionats amb l’arquitectura DAOBS i el seu funcionament. En primer lloc, es proposa un model matemàtic per aproximar el retard d’accés inferior i superior com a conseqüència de l’accés QA. En segon lloc, es formula matemàticament la generació i optimització de les topologies virtuals que suporten el protocol per a l’escenari amb tràfic estàtic. Finalment, l’última contribució explora els beneficis d’una arquitectura de xarxa òptica per temps compartit (TSON) basada en elements de càlcul de camins (PCE) centralitzats per tal d’evitar col·lisions en la xarxa. Aquesta arquitectura permet garantir l’aprovisionament orientat a connexió de canals sub-longitud d’ona. En aquest capítol proposem i simulem tres arquitectures GMPLS/PCE/TSON. A causa del enfocament centralitzat, el rendiment de la xarxa depèn en gran mesura de l’assignació i aprovisionament de les connexions. Amb aquesta finalitat, es proposen diferents algorismes d’assignació de ranures temporals i es comparen amb les corresponents formulacions de programació lineal (ILP) per al cas estàtic. Per al cas de tràfic dinàmic, proposem i avaluem mitjançant simulació diferents heurístiques. Els resultats mostren els beneficis de proporcionar flexibilitat en els dominis temporal i freqüencial a l’hora d’assignar les ranures temporals.

    The rapid evolving Internet and the broad range of new data applications (e.g., multimedia, video-conference, online gaming, etc.) is fostering revolutionary changes in the way we communicate. In addition, some of these applications demand for unprecedented amounts of bandwidth resources with diverse quality of service (QoS). The development of wavelength division multiplexing (WDM) in the 90's made very cost-effective the availability of bandwidth. Nowadays, optical circuit switching technologies are predominant in the core enabling the set up of lightpaths across the network. However, full-wavelength lightpath granularity is too coarse, which results to be inefficient for provisioning sub-wavelength channels. As remarked by the research community, an open issue in optical networking is increasing the protocol transparency as well as provisioning true dynamic bandwidth allocation at the network level. To this end, new architectures are required. Optical burst/packet switching (OBS/OPS) are two such proposed technologies under investigation. This thesis contributes with three network architectures which aim at improving the sub-wavelength data transport from different perspectives. First, we gain insight into the connectionless nature of OBS. Here, the network dynamics are increased due to the short-lived burst transmissions. Moreover, burst contentions degrade the performance even at very low loads. To cope with them, we propose a proactive resolution scheme by means of a distributed auto load-balancing routing and wavelength assignment (RWA) algorithm for wavelength-continuity constraint networks. In this protocol, the RWA and burst forwarding is based on the exploitation and exploration of switching rule concentration values that incorporate contention and forwarding desirability information. To support such architecture, forward and backward control packets are used in the burst forwarding and updating rules, respectively. In order to analyze the benefits of the new algorithm, four different network topologies are used. Results indicate that the proposed method outperforms the rest of tested RWA algorithms at various margins depending on the topology without penalizing other parameters such as end-to-end delay. The second contribution proposes a hybrid connectionless and connection-oriented architecture based on a medium access control (MAC) protocol for OBS networks (DAOBS). The MAC provides two main access mechanisms: queue arbitrated (QA) for connectionless bursts and pre-arbitrated (PA) for TDM connection-oriented services. Such an architecture allows for a broad range of delay-sensitive applications or guaranteed services. Results evaluated through simulations show that in the QA access mode highest priority bursts are guaranteed zero losses and very low access latencies. Regarding the PA mode, we report that doubling the offered TDM traffic load increases in more than one order their connection blocking, slightly affecting the blocking of other connectionless bursts. In this chapter, we also tackle two of the issues related with the DAOBS architecture and its operation. Firstly, we model mathematically the lower and upper approximations of the access delay as a consequence of the connectionless queue arbitrated access. Secondly, we formulate the generation of the virtual light-tree overlay topology for the static traffic case.

  • Arquitectura híbrida óptica-inalámbrica para servicios tolerantes a retardos e interrupciones - UPC

     Agusti Torra, Anna; Cervello Pastor, Cristina; García García, Aurelio J.; Remondo Bueno, David; Triay Marques, Joan; Guasch Murillo, Daniel; Gutierrez Gonzalez, Luis Maria; Jiménez Agudelo, Yury; Raspall Chaure, Federico; Rincon Rivera, David; Sallent Ribes, Sebastia
    Participation in a competitive project

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    Time Shared Optical Network (TSON): a novel metro architecture for flexible multi-granular services  Open access

     Zervas, Georgios S.; Triay Marques, Joan; Amaya, Norberto; Qin, Yixuan; Cervello Pastor, Cristina; Simeonidou, Dimitra
    Optics express
    Date of publication: 2011-11-28
    Journal article

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    This paper presents the Time Shared Optical Network (TSON) as metro mesh network architecture for guaranteed, statistically-multiplexed services. TSON proposes a flexible and tunable time-wavelength assignment along with one-way tree-based reservation and node architecture. It delivers guaranteed sub-wavelength and multi-granular network services without wavelength conversion, time-slice interchange and optical buffering. Simulation results demonstrate high network utilization, fast service delivery, and low end-to-end delay on a contention-free subwavelength optical transport network. In addition, implementation complexity in terms of Layer 2 aggregation, grooming and optical switching has been evaluated.

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    Demonstration of C/S based hardware accelerated QoT estimation tool in dynamic impairment-aware optical network  Open access

     Qin, Yixuan; Cheng, Kevin C.S.; Triay Marques, Joan; Escalona, Eduard; Zervas, Georgios S.; Zarris, George; Amaya González, Norberto; Cervello Pastor, Cristina; Nejabati, Reza; Simeonidou, Dimitra
    European Conference and Exposition on Optical Communications
    Presentation of work at congresses

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    An enhanced version of hardware accelerated QoT estimation tool in impairment-aware optical network is demonstrated and evaluated against the different number of lightpaths and wavelengths per link. It outperforms the software version by 28 times in the order of millisecond.

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    Experimental demonstration of a novel QoS-aware hybrid optical network  Open access

     Escalona, Eduard; Qin, Yixuan; Zervas, Georgios; Triay Marques, Joan; Zarris, George; Amaya González, Norberto; Nejabati, Reza; Cervello Pastor, Cristina; Simeonidou, Dimitra
    European Conference and Exposition on Optical Communications
    Presentation's date: 2010-09
    Presentation of work at congresses

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    This paper presents a hybrid optical test-bed controlled by a hardware-accelerated control plane capable of dynamically provisioning the most suitable route according to the requirements of the client technology and the physical characteristics of the network.

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    Experimental demonstration of a self-optimised multi-bit-rate optical network  Open access

     Zervas, Georgios S.; Zarris, George; Amaya González, Norberto; Triay Marques, Joan; Escalona, Eduard; Qin, Yixuan; Cervello Pastor, Cristina; Nejabati, Reza; Simeonidou, Dimitra
    European Conference and Exposition on Optical Communications
    Presentation's date: 2010-09-22
    Presentation of work at congresses

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    This paper proposes an innovative self-managed optical network architecture for heterogenous transparent optical networks. A self-optimized dynamic network testbed that comprises multiple multi bit-rate ligthpaths on a mesh topology that utilizes a dark fiber link has been implemented and evaluated.

  • Multi-service MAC-enabled OBS networks

     Triay Marques, Joan; Zervas, Georgios; Cervello Pastor, Cristina; Nejabati, Reza; Simeonidou, Dimitra
    Optical Fiber Communication Conference and Exposition and National Fiber Optic Engineers Conference
    Presentation's date: 2010-03
    Presentation of work at congresses

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    In this paper, a novel multi-service architectural solution based on a MAC protocol for mesh OBS networks is designed and the network performance among TDM services and connectionless burst transmissions is evaluated through simulations.

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    An ant-based algorithm for distributed routing and wavelength assignment in dynamic optical networks  Open access

     Triay Marques, Joan; Cervello Pastor, Cristina
    IEEE journal on selected areas in communications
    Date of publication: 2010-05
    Journal article

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    Future optical communication networks are expected to change radically during the next decade. To meet the demanded bandwidth requirements, more dynamism, scalability and automatism will need to be provided. This will also require addressing issues such as the design of highly distributed control plane systems and their associated algorithms to respond to network changes very rapidly. In this work, we propose the use of an ant colony optimization (ACO) algorithm to solve the intrinsic problem of the routing and wavelength assignment (RWA) on wavelength continuity constraint optical networks. The main advantage of the protocol is its distributed nature, which provides higher survivability to network failures or traffic congestion. The protocol has been applied to a specific type of future optical network based on the optical switching of bursts. It has been evaluated through extensive simulations with very promising results, particularly on highly congested scenarios where the load balancing capabilities of the protocol become especially efficient. Results on a partially meshed network like NSFNET show that the ant-based protocol outperforms other RWA algorithms under test in terms of blocking probability without worsening other metrics such as mean route length.

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    Next Generation Optical Access Networks: from TDM to WDM  Open access

     Gutierrez Gonzalez, Luis Maria; Garfias Hernandez, Paola; de Andrade Jardin, Marilet; Cervello Pastor, Cristina; Sallent Ribes, Sebastia
    Date of publication: 2010-03
    Book chapter

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    Postprint (author’s final draft)

  • ONDM 2010 Travel Grant Award

     Triay Marques, Joan; Cervello Pastor, Cristina
    Award or recognition

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  • Arquitectura de red y algoritmos para el diseño de la internet de futuro

     Agusti Torra, Anna; Cervello Pastor, Cristina; De Andrade Jardin, Marilet; Guasch Murillo, Daniel; Gutierrez Gonzalez, Luis Maria; Raspall Chaure, Federico; Rincon Rivera, David; Sallent Ribes, Sebastia; Triay Marques, Joan
    Participation in a competitive project

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  • Networking Innovations Over Virtualized Infrastructures

     Cervello Pastor, Cristina; Monje Hernandez, Alvaro
    Participation in a competitive project

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  • SILVIA

     Cervello Pastor, Cristina; Riba Grifell, Oriol; Fernández Molina, Pablo
    Participation in a competitive project

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  • AJUT ICREA ACADEMIA 2010

     Junyent Giralt, Gabriel; Mataix Oltra, Jorge; Sallent Ribes, Sebastia; Alcober Segura, Jesus Angel; Rincon Rivera, David; Cervello Pastor, Cristina; Paradells Aspas, Jose; Garcia Ojalvo, Jorge
    Participation in a competitive project

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    QoS-Enabled distributed access on optical burst-switched networks  Open access

     Triay Marques, Joan; Zervas, Georgios; Cervello Pastor, Cristina; Nejabati, Reza; Simeonidou, Dimitra
    International Conference on Optical Networking Design and Modeling
    Presentation's date: 2010-02-03
    Presentation of work at congresses

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    Optical Burst Switching (OBS) has been proposed as an efficient technology to cope with the ever increasing bursty traffic on the Internet. The emergence of a broad range of network-driven applications (e.g. multimedia, online gaming)introduces the need for a network environment able to provide service with different Quality of Service (QoS) guarantees. Burst loss probability, as one of the main QoS metrics on bufferless OBS networks, plays a considerable role on providing a network service with a particular level of QoS. In this paper, a novel MAC based protocol is proposed to support multiple QoS levels on OBS networks without wavelength conversion. It has been evaluated through extensive simulations and its simplistic form makes it very promising. Results indicate that the protocol can clearly provide a relative differentiation of services and guarantee null (or negligible) burst loss probability for a wide network (or offered) load range and, finally, low access delay for the highest priority traffic.

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    Multiservice QoS-enabled MAC for optical burst switching  Open access

     Triay Marques, Joan; Zervas, Georgios S.; Cervello Pastor, Cristina; Simeonidou, Dimitra
    Journal of optical communications and networking
    Date of publication: 2010-07-14
    Journal article

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    The emergence of a broad range of network-driven applications (e.g., multimedia, online gaming) brings in the need for a network environment able to provide multiservice capabilities with diverse quality-of-service (QoS) guarantees. In this paper, a medium access control protocol is proposed to support multiple services and QoS levels in optical burst-switched mesh networks without wavelength conversion. The protocol provides two different access mechanisms, queue-arbitrated and prearbitrated for connectionless and connection-oriented burst transport, respectively. It has been valuated through extensive simulations and its simplistic form makes it very promising for implementation and deployment. Results indicate that the protocol can clearly provide a relative quality differentiation for connectionless traffic and guarantee null (or negligible, and thus acceptable) burst loss probability for a wide range of network (or offered) load while ensuring low access delay for the higher-priority traffic. Furthermore, in the multiservice scenario mixing connectionless and connection-oriented burst transmissions, three different prearbitrated slot scheduling algorithms are evaluated, each one providing a different performance in terms of connection blocking probability. The overall results demonstrate the suitability of this architecture for future integrated multiservice optical networks.

  • Sistema y procedimiento para generar ráfagas de datos

     Triay Marques, Joan; Cervello Pastor, Cristina; Fernández Molina, Pablo; Riba Grifell, Oriol
    Date of request: 2010-06-18
    Invention patent

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    Sistema y procedimiento para generar ráfagas de datos en un sistema de computación que comprende unos primeros medios de almacenamiento de datos (20), para la ejecución de dicho procedimiento en comunicaciones de sistemas Optical Burst Switching. Así, mediante dicho sistema y procedimiento es posible generar ráfagas de datos a partir de paquetes IP de manera rápida y sencilla, ahorrando tiempo de computación del proceso y aprovechando así el ancho de banda del sistema de comunicaciones utilizado.

  • Load-balanced wavelength assignment strategies for optical burst/packet switching networks

     Agusti Torra, Anna; Cervello Pastor, Cristina; Fiol Mora, Miquel Àngel
    IET communications
    Date of publication: 2009-03
    Journal article

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    Loss-free schemes are defined to ensure successful packet/burst transmissions in optical packet/burst switching networks. To this end, they rely on a collision-free routing and wavelength assignment (CF-RWA) scheme combined with simple contention resolution mechanisms that guarantee the absence of losses in intermediate links. Here, the CF-RWA problem is studied. In particular, by using graph theory, the problem of finding CF-RWA schemes that minimise the number of wavelengths to serve a given traffic matrix is set. The problem is simplified when it is formulated by using pre-defined sets of non-colliding paths. Within this framework, the problem is shown to be equivalent to finding a given vertex-set colouring of the so-called restriction digraph. Here, two heuristic algorithms are proposed to obtain such vertex-set colourings. One of them provides a suitable CF-RWA without having to solve the minimisation problem. By way of example, the proposed method is applied to the NSFNet and the EON network providing quasi-optimal results.

  • A Routing and Wavelength Assignment Strategy for Successful Transmission in Optical Networks

     Agusti Torra, Anna; Cervello Pastor, Cristina; Fiol Mora, Miquel Àngel
    Journal of interconnection networks
    Date of publication: 2009-01
    Journal article

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    With evolution for revolution: managing FEDERICA for future Internet research  Open access

     Szegedi, P; Figuerola, S; Campanella, M; Maglaris, Vasilis; Cervello Pastor, Cristina
    IEEE communications magazine
    Date of publication: 2009-07
    Journal article

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    Over the last two decades the importance of data networking for human beings and systems has increased beyond any expectation in size, complexity, and impact on society. Today, technology offers the ubiquitous and constant possibility of being connected to the Internet at a wide range of speeds. Traditional management solutions have up to now followed an evolutionary path, although the scale of the Internet and emerging novel architectures such as peer-to-peer, ad hoc networks, as well as virtualization-capable network infrastructures require focused and possibly revolutionary changes in management approaches. This article elaborates on challenges posed by the renaissance of virtualization as experienced in the planning, development, and operation of the FEDERICA infrastructure. The European Community cofunded project FEDERICA, like other worldwide initiatives such as FIND/GENI in the United States, NWGN in Japan, and the FIRE program in Europe, is supporting the development of the future Internet. FEDERICA extends the virtualization capabilities of the current hardware and software to provide a flexible infrastructure to host disruptive testing by networking researchers.

    Postprint (author’s final draft)

  • Loss-Free Strategies for Optical Burst and Packet Switched Networks.

     Agusti Torra, Anna
    Defense's date: 2009-06-26
    Department of Telematics Engineering, Universitat Politècnica de Catalunya
    Theses

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  • Integration of Optical and Wireless Technologies in the Metro-Access: QoS Support and Mobility Aspects

     Remondo Bueno, David; Nunes, Mario; Sargento, Susana; Cesana, Matteo; Filippini, Ilario; Triay Marques, Joan; Agusti Torra, Anna; de Andrade Jardin, Marilet; Gutierrez Gonzalez, Luis Maria; Sallent Ribes, Sebastia; Cervello Pastor, Cristina
    Conference on Next Generation Internet Design and Engineering
    Presentation's date: 2009-07-03
    Presentation of work at congresses

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    Utilización de un simulador de redes OBS para evaluar servicios de tele-asistencia  Open access

     Guasch Murillo, Daniel; Roca, David; Cervello Pastor, Cristina; Ponsa Asensio, Pedro
    Congreso Internacional de Domótica, Robótica y Teleasistencia para todos (3r : 2009 : Barcelona)
    Presentation of work at congresses

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    Día a día aparecen nuevas tecnologías que pueden aplicarse, directa o indirectamente, en la prestación de servicios de tele-asistencia. Las TIC, Tecnologías de la Información i Comunicaciones, no son una excepción. Disponer de herramientas que permitan evaluar el comportamiento de dichas tecnologías, previa su implantación en el entorno de explotación, supone una enorme ventaja. Las redes de transporte de conmutación óptica de ráfagas, OBS, ofrecen una alternativa en el transporte masivo de datos en entornos inteligentes. A continuación se presenta un simulador de redes OBS desarrollado por el grupo de Servicios y Redes de Banda ancha del departamento de Ingeniería Telemática de la Universidad Politécnica de Catalunya.

  • PAIS: Plataforma Avançada Integrada de Serveis

     Cervello Pastor, Cristina; Riba Grifell, Oriol
    Participation in a competitive project

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    An Ant-based Algorithm for Distributed RWA in Optical Burst Switching  Open access

     Triay Marques, Joan; Cervello Pastor, Cristina
    International Conference on Transparent Optical Networks
    Presentation's date: 2009-07-01
    Presentation of work at congresses

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    To meet the demanded bandwidth requirements of future optical communication networks, more dynamism, scalability and automatism will need to be provided, which will require, as well, new control plane designs to respond to network changes very rapidly. In this work, we propose the use of an ant colony optimization (ACO) algorithm to support the routing and wavelength assignment in wavelength continuity constraint optical burst-switched networks. The main advantage of the protocol is its distributed nature, which provides higher survivability to network failures or traffic congestion. From the results we see that the new protocol responds effectively to congestion while at the same time providing better performance in comparison to the shortest path routing with random wavelength assignment.

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    On avoiding-minimizing burst collisions in optical burst-switched networks without wavelength conversion  Open access

     Triay Marques, Joan; Perello Muntan, Jordi; Cervello Pastor, Cristina; Spadaro, Salvatore
    International Conference on Transparent Optical Networks
    Presentation's date: 2009-07-01
    Presentation of work at congresses

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    In this paper, a new MAC protocol for OBS networks is introduced, described and evaluated. Into operation, DAOBS avoids burst collisions in the core of the network by controlling the way OBS nodes access the optical channel. Assuming no wavelength conversion capabilities in the network, DAOBS is assessed and compared to standard deflection routing through simulations. From the results, DAOBS offers zero collisions at low-tomedium network loads without excessively deteriorating the burst end-to-end delay. This makes DAOBS particularly useful either in network scenarios where the increased costs related to wavelength converters arise as prohibitive, or as a mid-term OBS network solution until wavelength conversion becomes sufficiently mature.

  • XARXES I SERVEIS DE BANDA AMPLA

     Guasch Murillo, Daniel; Domingo Aladren, Maria Del Carmen; Agusti Torra, Anna; Raspall Chaure, Federico; Remondo Bueno, David; Barba Marti, Antonio; Cervello Pastor, Cristina; Hesselbach Serra, Xavier; Alcober Segura, Jesus Angel; Triay Marques, Joan; Mataix Oltra, Jorge; Rincon Rivera, David; Oller Arcas, Antonio; Gutierrez Gonzalez, Luis Maria; Sallent Ribes, Sebastia
    Participation in a competitive project

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    Distributed Resources Assignment for Optical Burst Switching without Wavelength Conversion (Invited Paper)  Open access

     Cervello Pastor, Cristina; Triay Marques, Joan; Sallent Ribes, Sebastia
    Nineth IEEE / CreateNet International Workshop on Optical Burst/Packet Switching (WOBS'09) held in conjunction with Sixth International Conference on Broadband Networks (BROADNETS 2009)
    Presentation's date: 2009-09-14
    Presentation of work at congresses

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    The amount of bursty Internet traffic leads to develop new architectures and technologies, such as Optical Burst Switching (OBS), to efficiently satisfy future bandwidth requirements. Burst loss probability is an important quality of service metric for OBS due to its bufferless characteristic, even more critical without wavelengths converters. So, resource assignment is an important issue to solve in OBS networks. In this paper, two distributed resources assignment schemes without wavelength conversion capability are proposed. Whereas the first one is applied at the edge nodes to achieve a loss-free core network, the second is an enhanced routing and wavelength assignment scheme applied at core nodes. Simulation results indicate that the first scheme offers a loss-free solution with blocking probability only at ingress nodes and high traffic load. The second one reduces the network-wide burst loss probability significantly compared with other schemes.

  • A general resource assignment scheme for successful transmission in optical burst switched networks

     Agusti Torra, Anna; Cervello Pastor, Cristina; Fiol Mora, Miquel Àngel
    Optical switching and networking
    Date of publication: 2008-10
    Journal article

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    QoS Multi-Spanning Tree for Optical Burst Switching  Open access

     Triay Marques, Joan; Cervello Pastor, Cristina
    2008 4th International Telecommunication Networking Workshop on QoS in Multiservice IP Networks
    Presentation's date: 2008-02-13
    Presentation of work at congresses

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    Optical Burst Switching (OBS) has been proposed as a future high-speed switching technology for Internet Protocol (IP) networks that may be able to efficiently utilize extremely high capacity links without the need for optical-electronic (O/E) conversions at intermediate nodes. Among its benefits of supporting statistical multiplexing at a rational granularity, OBS still gives poor performance in terms of burst drop probability. In an Optical Burst Switched network, the existence of highly congested links could lead to unacceptable performance for the entire network, causing Quality of Service (QoS) degradation to flows inserted into the network. In this paper we propose a Multi-Spanning Tree architecture that improves QoS management by increasing the efficiency in the wavelength assignment process. The new protocol uses wavelength spanning trees on demand depending on the QoS constraints demanded by inserted traffics. Moreover, the protocol avoids burst overlapping on each edge of the spanning trees, while at the same time, permitting the reutilization of lambda assignments between nodes contained in the same branch. Therefore, the protocol allows traffic aggregation from many nodes into a single branch, improving efficiency and link utilization. We take a traffic engineering approach to branch selection with the objective of balancing the traffic across the network links to reduce congestion and to improve overall performance. In this paper, the architecture, the design of the protocol and some simulation results are presented.

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    Distributed Contention Avoidance in Optical Burst-Switched Ring Networks  Open access

     Triay Marques, Joan; Cervello Pastor, Cristina
    Eleventh IEEE International Conference on Communications Systems (ICCS 2008)
    Presentation's date: 2008-11-20
    Presentation of work at congresses

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    Optical Burst Switching (OBS) is a promising technology for future optical networks. Due to its less complicated implementation using current optical and electrical components, OBS is seen as the first step towards the future Optical Packet Switching (OPS). Regarding network topologies, the ring is extensively used on current metropolitan environments, and this does not seem it will change in the foreseeable future. In this paper we propose a new medium access protocol for Optical Burst-Switched Networks over metropolitan rings that enables the nodes to access the channel in a distributed way. This new protocol avoids burst blockings in transit nodes, turning itself into an efficient and simple burst contention avoidance mechanism. The use of this protocol maximizes the throughput of the network without deteriorating excessively other parameters such as end-to- end delay or ingress queues.

  • FI-WI (FIbre-WIreless Access: Future Integrated Access Architecture Based on Optical and Broadband Wireless Technologies)

     Remondo Bueno, David; Agusti Torra, Anna; Cervello Pastor, Cristina; Gutierrez Gonzalez, Luis Maria; Sallent Ribes, Sebastia; Triay Marques, Joan; De Andrade Jardin, Marilet; Garfias Hernandez, Paola
    Participation in a competitive project

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  • Federated E-infrastructure Dedicated to European Researchers Innovating in Computing network Architectures (FEDERICA)

     Cervello Pastor, Cristina; Monje Hernandez, Alvaro; Machado Calvo, Robert; Oskarsson, Asgeir
    Participation in a competitive project

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  • Tools for the design and analysis of optical and wired access networks

     Triay Marques, Joan; Cervello Pastor, Cristina; de Andrade Jardin, Marilet; Sallent Ribes, Sebastia
    Date: 2008-04
    Report

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  • Evaluation of current network control and management plane for multi-domain network infrastructure

     Cervello Pastor, Cristina; Machado, Robert; Kauffman, Peter; Roesler, Monika; Monaco, Ugo; Figuerola, Sergi; Berna Juan, Alejandro; Pons, Josep; Sevasti, Afrodite; Kagoleras, Dimitrios; Uze, Jean Marc; Sjödin, Peter; Hidell, Markus; Dolata, Lukasz; Potts, Martin; Campanella, Mauro
    Date: 2008-07
    Report

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