Search

Este proyecto consiste en el desarrollo de una herramienta que simula un enlace óptico de una red óptica pasiva Ethernet (EPON) sobre una topología árbol-rama diseñado para una urbanización ubicada vía Pascuales- La puntilla llamada Plaza Madeira. La herramienta implementada en el software llamado MATLAB es capaz de desarrollar una cálculo de presupuesto de ancho de banda, presupuesto de enlace, pérdidas totales del enlace, tasa de datos del enlace de bajada y enlace de subida, tiempo de respuesta del sistema y un gráfico de distancia vs potencia; lo cual se mostrará mediante una herramienta de MATLAB llamada guide. La simulación se desarrolla sobre dos esquemas propuestos los cuales poseen componentes que obedecen al estándar IEEE 802.3 ah (EPON) y lo cual nos permitirá conocer cómo van a reaccionar los enlaces a causas de pérdidas generadas en los enlaces ópticos y si es factible su implementación en la vida real en base a los resultados de la simulación.

Dynamic bandwidth allocation in EPONs can be generally separated into inter-ONU scheduling and intra-ONU scheduling. In our previous work, the active intra-ONU scheduling (AS) utilizes multiple queue reports (QRs) in each report message to cooperate with the inter-ONU scheduling and makes the granted bandwidth fully utilized without leaving unused slot remainder (USR). This scheme successfully solves the USR problem originating from the inseparability of Ethernet frame. However, without proper setting of threshold value in AS, the number of QRs constrained by the IEEE 802.3ah standard is not enough, especially in the unbalanced traffic environment. This limitation may be solved by enlarging the threshold value. The large threshold implies the large gap between the adjacent QRs, thus resulting in the large difference between the best granted bandwidth and the real granted bandwidth. In this paper, we integrate AS with a cooperative prediction mechanism and distribute multiple QRs to reduce the penalty brought by the prediction error. Furthermore, to improve the QoS and save the usage of queue reports, the highest priority (EF) traffic which comes during the waiting time is granted automatically by OLT and is not considered in the requested bandwidth of ONU. The simulation results show that the proposed scheme has better performance metrics in terms of bandwidth utilization and average delay for different classes of packets., {"references":["G. Kramer and G. Pesavento, \"Ethernet PON: Building a Next-Generation Optical Access Network,\" IEEE Commune. Mag., vol.\n40, no. 2, pp. 66-73, Feb. 2002.","IEEE Std. 802.3ah for Information Technology-Telecommunications and\nInformation Exchange Between Systems-Local and Metropolitan Area\nNetwork-Specific Requirements Part, IEEE Std. 802.3ah, Jul. 2004.","H. J. Byun, I. M. Nho, and J. T. Lim, \"Dynamic Bandwidth Allocation Algorithm in Ethernet Passive Optical Networks,\" Electronics Letters,\nvol. 39, no. 13, pp. 1001-1002, Jun. 2003.","H. J. Byun, I. M. Nho, and J. T. Lim, \"Dynamic Bandwidth Allocation Algorithm in Ethernet Passive Optical Networks,\" Electronics Letters, vol. 39, no. 13, pp. 1001-1002, Jun. 2003.","J. Zheng and H. T. Mouftah, \"Media Access Control for Ethernet Passive\nOptical Networks: An Overvew,\" IEEE Comm. Mag., vol. 43, no. 2, pp.\n145-150, 2005.","M. Mcgarry, M. Reisslein, and M. Maier, \"Ethernet Passive Optical\nNetwork architectures, and dynamic bandwidth allocation algorithms,\" IEEE Comm. Surveys. & Tutorials, vol. 10, no. 3, pp. 46-60, 2008.","G. Kramer and B. Mukherjee, \"Supporting Differentiated Classes of\nService in Ethernet Passive Optical Networks.\" Journal of Optical Networking, vol. 1, Issue 8, pp. 280-298, 2002.","G. Kramer, Ethernet Passive Optical Network, McGraw-Hill, 2005.","C. C. Sue, W. N. Sung and H. Y. Chen, \"Active Scheduling Algorithm for\nIntra-ONU Dynamic Bandwidth Allocation in Ethernet Passive Optical\nNetworks,\" International Conference on Ubiquitous and Future\nNetworks, pp. 240-245, 2009.\n[10] S. Blake, D. Black, M. Carlson, E. Davies, Z. Wang, and W. Weiss, \"An\nArchitecture for Differentiated Services,\" IETF, RFC 2475, Dec. 1998.\n[11] X. Bai, A. Shami, and C. Assi, \"On the Fairness of Dynamic Bandwidth\nAllocation Schemes in Ethernet Passive Optical Networks,\" Computer\nCommunications, vol. 29, pp. 2123-2135, 2006.\n[12] Y. Luo and N. Ansari, \"Limited Sharing with Traffic Prediction for Dynamic bandwidth allocation and QoS provisioning over ethernet passive optical networks,\" Journal of Optical Networks, pp. 561-572, 2005.\n[13] OMNeT++, http://www.omnetpp.org.\n[14] H. Miyoshi, T. Inoue, and K. Yamashita, \"QoS-Aware Dynamic\nBandwidth Allocation Scheme in Gigabit-Ethernet Passive Optical\nNetworks,\" IEEE International Conference on, pp. 90-94, 2004.\n[15] D. Nikolova, B. Van Houdt, and C. L. Blondia, \"Dynamic Bandwidth\nAllocation Algorithms in EPON: a Simulation Study,\" Optical Networking and Communications SPIE, pp. 1-12, 2003.\n[16] W. Willinger, M. Taqqu, R. Sherman, and D. Wilson, \"Self-Similarity\nThrough High Variability: Statistical Analysis of Ethernet LAN Traffic at\nthe Source Level,\" Proc. ACM Sigcomm, pp. 100-113, 1995.\n[17] M. S. Taqqu, W.Willinger, and R. Sherman,\"Proof of a Fundamental Result in Self-Similar Traffic Modeling,\" ACM/SIGCOMM Comput. Commun. Rev., vol. 27, no. 2, pp. 5-23, Apr. 1997."]}

El desarrollo de tecnologías de red de acceso basadas en el uso de la fibra óptica como medio de transmisión ha permitido, en comparación con las redes de acceso de cable, incrementar en varios órdenes de magnitud la capacidad de transmisión de datos en el segmento más cercano al usuario. Las redes de acceso ópticas pasivas (Passive Optical Networks, PONs) se caracterizan por no tener componentes activos intermedios entre el usuario y la central. Entre ellas se definen las redes Ethernet PON (EPON), cuya arquitectura se basa en el transporte de tráfico Ethernet, manteniendo las características de la especificación 802.3 sobre fibra óptica. En la red troncal la fibra óptica es el medio de transmisión predominante, siendo la conmutación de circuitos la técnica más utilizada debido, principalmente, a la falta de un equivalente real a las memorias de acceso aleatorio (Random Access Memory, RAM) que permita soportar conmutación de paquetes en el dominio óptico. Para poder beneficiarse de las ventajas del multiplexado estadístico de usuarios que proporciona la conmutación de paquetes sin los requisitos tecnológicos que supone su implementación en redes ópticas, se definió la conmutación óptica de ráfagas (Optical Burst Switching, OBS). En OBS, los datos de los usuarios se agregan en los nodos frontera formando unidades de datos de longitud superior (ráfagas). Antes de la transmisión de cada ráfaga, se envía un paquete de control con el objetivo de configurar los dispositivos intermedios, permitiendo así que el envío de los datos se pueda realizar íntegramente en el dominio óptico. El presente estudio desarrolla el escenario de simulación que interconecta una red de acceso EPON con una red troncal basada en la tecnología de conmutación OBS.

17th IEEE Symposium on Computers and Communication, ISCC 2012 -- 1 July 2012 through 4 July 2012 -- Cappadocia -- 92819 This study is about a prediction approach for our previous dynamic bandwidth allocation algorithm for Ethernet Passive Optical Networks (EPON). Our previous work (hcDBA) is based on half cycle timing for bandwidth allocation. That can be handled as a middle way between online and offline bandwidth allocation schemes. In PONs, prediction is used for bandwidth allocation to grant loaded nodes with early responses. However, due to the versatile nature of data traffic, prediction algorithms have a handicap to provide a better solution in classical approaches. In this study, a novel prediction approach integrated with hcDBA algorithm described. Performance comparison of hcDBA with & without prediction and IPACT algorithm is given. According to the simulation results, prediction on hcDBA seems to give some performance improvements in terms of access-delay. © 2012 IEEE.

7th International Wireless Communications and Mobile Computing Conference, IWCMC 2011 -- 4 July 2011 through 8 July 2011 -- Istanbul -- 86373 Metropolitan ring networks are usually used to connect the high speed backbone networks with access networks. Until now, the metropolitan network and the access network are gained much attention of researchers. However they have been investigated in separate ways. There is no work in which the end-to-end performance from end-users of the access network to metropolitan network is evaluated. How to simulate a complete end-to-end network while keeping basic characteristics of access and metro traffic is an emergence problem to evaluate the end-to-end performance. In reality, a complete end-to-end network in which hundreds of Ethernet Passive Optical Network (EPON) are connected to metro ring networks cannot be simulated because of the huge amount of traffic generated from the access network side. In this paper, we aim to obtain trace files of incoming traffic at the entrance of Optical Line Terminal (OLT) by running simulations of an EPON network which implements Interleaved Polling with Adaptive Cycle Time (IPACT). Then, the generated traffic pattern will be characterized in order to find corresponding traffic model among well known traffic models and this model will be used as output traffic of OLTs. After, we can use this traffic model without simulating a complete EPON network. Through various simulations, we observe that the generated traffic that comes to OLT is similar to the traffic obtained with Poisson sources © 2011 IEEE.

As concerns about energy consumption grow, the power consumption of the EPON becomes a matter of increasing importance. In respect of energy efficiency, the current standard has no management protocols aiming to reduce power consumption in EPONs. In this paper, we propose an Energy Management Mechanism (EMM) for downlink EPON systems. The proposed mechanism is designed to enhance the standardized control scheme in EPON with the objective to increase energy efficiency while satisfying diverse QoS requirements. The main idea is to put an Optical Network Unit (ONU) into the sleep mode and determine a suitable wakeup time scheduler at the Optical Line Terminal (OLT). A generic EPON system is considered, which is composed of an OLT and several ONUs that are EMM enabled. An energy consumption optimization problem aimed at saving energy is proposed and two heuristic sleep mode scheduling policies are addressed to solve it. The scheduling algorithms are tightly coupled with the upstream bandwidth allocation and downstream trans mission scheduling together through an integrated approach in which awake time in ONUs is minimized. There is a trade-off decision between maximizing the power saving and guaranteeing the network performance at the same time. Simulation results show that an EMM-based EPON with well designed scheduling disciplines is essential to achieving significant energy saving while meeting the delay constraint.

The emergence of bandwidth-intensive Internet services, such ascircuit-quality voice transfer and interactive video gaming, createa high demand for a very qualified next-generation access network.In addition to high bandwidth, these future access networks shouldalso provide improved network availability, flexibility, mobility,reliability, failure protection, quality of service (QoS) supportand cost-effective access. The integration between optical networksand Worldwide Interoperability for Microwave Access (WiMAX) is apromising solution for future access networks. Accordingly, a fewdifferent architectures and MAC protocol components have recentlybeen proposed for the integration between the Ethernet PassiveOptical Network (EPON) and WiMAX. However, the proposedarchitectures contain several drawbacks. Moreover, the EPON-WiMAXhybrid does not yet contain a comprehensive Medium Access Control(MAC) protocol and a mechanism for Quality of Service (QoS) support.Finally, this work introduces the Resilient Packet Ring (RPR)standard, which aims to build high-performance metro edge and metrocore ring networks that interconnect multiple access networks. Theobjective of this thesis is to examine the integration of opticalstandards, such as RPR and EPON, with the WiMAX standard.Subsequently, this integration will be applied to the areas ofarchitecture and MAC Protocol as a promising solution for not onlyaccess networks but also for metro networks.The first part of the thesis examines the EPON-WiMAX integration asa solution for the access network. Specifically, the proposedsolution includes new EPON-WiMAX hybrid network architectures thatare suitable for both urban and rural environment requirements, andit also introduces a joint MAC protocol for these architectures. Theproposed architectures are reliable and provide extended networkcoverage; in particular, reliability is achieved by applying aprotection scheme to the most critical portion of the EPON part ofthe architecture. Additionally, the network coverage of thearchitecture is extended by inserting an intermediate networkbetween the front end and the backhaul network of the traditionalEPON-WiMAX architecture. Subsequently, we propose a comprehensivejoint MAC protocol for the proposed EPON-WiMAX architecture; thisprotocol provides a per-stream quality-of-service guarantee andimproves the network utilization. Also, the proposed joint MACprotocol includes an admission controller, a scheduler and abandwidth allocator.While the first part of the thesis strives to improve the hybridnetwork reliability through protection in the EPON part and extendthe network coverage through innovative methods, the second partattempts to maintain and enhance these objectives by adding areliable technology to the integrated network. Specifically, thissection examines the way in which the RPR network can be integratedwith the proposed EPON-WiMAX architecture to form an RPR-EPON-WiMAXhybrid network, which can be a solution for both access and metronetworks. The proposed architecture is reliable due to thedependability of the RPR standard and the protection mechanismemployed in the EPON network. Moreover, the architecture contains ahigh fault tolerance against node and connection failure. In thesecond part, the joint MAC protocol for the RPR-EPON-WiMAX hybridnetwork includes a multi-level dynamic bandwidth allocationalgorithm, a distributed admission control, a scheduler, and arouting algorithm. This MAC protocol aims to maximize the advantagesof the proposed architecture by distributing its functionalitiesover the parts of the architecture and jointly executing the partsof the MAC protocol.

Optical transmission is getting more popular in the access network due to the increasing demand for bandwidth. This paper introduces an overview of Wavelength-Division-Multiplexed Passive Optical Network (WDM-PON) technology and Time- Division Multiplexing Passive Optical Network (TDM-PON) as well as different passive optical network architectures such as Gigabit PON (GPON), Broadband PON (BPON) and Ethernet PON (EPON).The advantages and disadvantages of each PON architecture is shown in this paper and the comparative results are provided.

In this paper end-to-end performance is evaluated when multiple high-speed access networks, based on the Ethernet Passive Optical Network (EPON) technology, are interconnected through an Optical Burst Switching (OBS) core network. The inter-working unit, or edge node, between these two different networks is properly studied and discussed. A time-based burst assembly algorithm is assumed, which is analyzed and dimensioned to cope with multiple EPONs. The role of a key parameter, such as the EPON cycle time used in the multiple access scheme, is assessed. Transport layer performance of the multi-EPON/OBS network is evaluated through simulations with ns2. Results show that the relationship between the EPON cycle time and the burst assembly time has a fundamental role and requires proper tuning to optimize, e.g., the TCP throughput.

In this paper the performance of a hybrid optical network composed of multiple Ethernet Passive Optical Networks (EPONs) at the access connected to an Optical Burst Switching (OBS) core is evaluated. The EPONs make use of the IPACT algorithm to manage the upstream transmissions, whereas the OBS edge node employs a time-based assembly scheme for burst aggregation. This leads to interoperability issues between access and core which are investigated in this paper. The hybrid network scalability is proved by assessing the transport layer performance with different numbers of EPONs served by the same burst assembler and different numbers of Optical Network Units (ONUs) per EPON. The impact of the main design parameters affecting the interaction between EPONs and OBS is estimated. The transport layer performance is evaluated considering heterogeneous traffic flows by simulating both TCP and UDP sources.

Energy management strategy has been considered as an important component in the future Ethernet Passive Optical Networks (EPONs). In this paper, a sleeping mode operation is studied, and a downlink packet scheduling scheme is analyzed to preserve energy consumption and maintain the required QoS. This paper proposes a novel sleep-mode downlink packet scheduling scheme in order to enhance the sleep control function. Simulation results confirm that the proposed approach offers effective power management on the basis of the traffic conditions. The trade-off between network performances and the power saving is examined and compared.

Currently, new housing developments in many places around the world are built with fiber-based connections to the home, and network providers are conducting field-testing and experiments with fiber access. In order to provide a worthy alternative to the existing infrastructures, the new technology should be, among other things, cost-efficient, broad-banded, and easy to maintain and deploy. It must also support all existing services as well as offer new required services. These services include voice, data, and video/television-broadcast traffic. In this project we will carry out exploration of some of the aspects of the QoS bandwidth allocation in the 802.3ah EPON architecture and the GPON architecture in a multimedia environment. Several general traffic types will be defined, that would represent real traffic in the network, each with its own QoS requirements (bandwidth, delay, etc.). Sometimes we will use real traffic (voice, video, data). Moreover, another goal of this project is to provide an operating and configuration reference tool-like manual facilitating the functional and performance analysis of this kind of networks. This tool-like manual will include step-by-step the way to discover the behaviour of these networks. Due to the required extension of this document, the manual has been included in Annex C.

International audience; Αυτό το άρθρο, βασισμένο σε μερικά τραγούδια, θέλει να δείξει τα κύρια ιδεολογικά θέματα της ΕΠΟΝ, χωρίς να ξεχάσει τα ειδικά ελληνικά δεδομένα. Η ΕΠΟΝ η οποία ιδρύθηκε από το ΕΑΜ, τη μεγαλύτερη οργάνωση της ελληνικής αντίστασης, είχε σκοπό να προσλαμβάνει παιδία κάθε ηλικίας, για δράση, ένοπλη ή μη, εναντίον των κατακτητών και να χτίσουν το λαμπρό και φωτεινό μέλλον το οποίο τους περίμενε στο τέλος του πολέμου. Το τραγούδι είναι βέβαια όπλο προπαγάνδας αλλά και ταυτόχρονα μία μορφή της παιδείας την οποία ανέλαβαν παντού τα στέλεχη της οργάνωσης. Δικαιοσύνη, δουλειά, παιδεία, ευημερία, ισότητα ανάμεσα στους άντρες και στις γυναίκες, όλα αυτά άγνωστα στην προπολεμική Ελλάδα, ήταν συνθήματα τα οποία δεν μπρορούσαν να μη τραβούν μια γενιά έτοιμη να θυσία με ενθουσιασμό.; Based on a number of songs, this communication summarizes the great ideological themes of EPON, while at the same time placing them in the specifically Greek context. Created by EAM, the national resistance movement, EPON set out to recruit the young of all ages, to make them participate in the civil and armed resistance against the occupiers, and to help them build the brilliant future they were promised at the end of the war. Song was one of the many forms of propaganda used by EPON, but also a real form of education undertaken everywhere by the heads of the organisation, who were often teachers. Justice, work, school, prosperity, equality between men and women, unknown realities in pre-war Greece that could only inspire enthusiasm and hope in a generation; Cette communication se propose, à travers quelques chants, de montrer les grands thèmes idéologiques de l'EPON, tout en la replaçant dans le cadre spécifique grec. Créée par le mouvement de résistance de masse du pays, l'EAM, l'EPON se propose d'encadrer les jeunes de tous âges, de les faire participer à la résistance, civile et parfois armée et de les conduire vers la construction de l'avenir radieux qui leur est promis à la fin de la guerre. Le chant fait partie des nombreux moyens de propagande utilisés par l'EPON (et précédemment par l'EON) mais aussi d'un réel travail d'éducation entrepris en tous lieux par les cadres de l'organisation, souvent des enseignants. Justice, travail, école, prospérité, égalité homme/femme, des réalités inconnues dans la Grèce de l'avant-guerre qui ne peuvent que provoquer enthousiasme et espérance dans une génération prête à se sacrifier généreusement.

L'objectiu d'aquest treball és desenvolupar, via simulació, un escenari d'interconnexió d'una xarxa d'Accés Optica Passiva (PON) amb una xarxa metro o troncal basada en la tecnologia de commutació OBS (Optical Burst Switching), on sigui possible estudiar i avaluar mecanismes DBA que tingui en compte la generació de les ràfegues al node d'entrada de la xarxa OBS per tal de minimitzar el retard total de transmissió d'informació.

The broadband photonics project (BBP) under the Freehand consortium of projects looks into the design of an extended access network. The network is a photonic network which can be dynamically reconfigured to distribute bandwidth in an optimised manner. This paper presents linear programming based formulations to calculate implementation of bandwidth redistribution in the network.

U ovom radu razmotrena je mogućnost realizacije širokopojasnih pristupnih mreža korištenjem Ethernet tehnologije. Obrađene su mogućnosti uvođenja Ethernet tehnologije preko postojeće razgranate mreže bakrenih parica, te problemi koji se kod takvih mreža pojavljuju. Prikazana je potreba za uvođenjem optike s razlogom povećanja udaljenosti na kojima je moguće pružiti širokopojasne usluge, a i zbog mogućnosti za povećanjem brzine prijenosa koje će od mreže zahtijevati uvođenjem novih širokopojasnih usluga. Ukazano je na važnost uspostavljanja efikasnog mehanizma nadzora i upravljanja EFM mrežama kako bi bilo moguće pružiti uslugu prema dogovorenim QoS zahtjevima. This thesis gives overview of broadband access networks realization based on Ethernet technology. Implementation possibility of Ethernet technology over existing copper access networks with problems were considered. It is described needs for introduce optical networks with reason to provision broadband services on extra distance with higher bandwidth. Importance of introduce EFM operations and maintenance mechanism to accomplish QoS requirements were described.

Tietoverkkojen käytön monipuolistuessa ja palvelujen kehittyessä kasvaa myös tiedonsiirtoyhteyksien nopeustarve. Vaativimpien palvelujen osalta kotikäyttäjien kaistantarve nousee jo kymmeniin megabitteihin sekunnissa. Optiset kuidut pystyvät tarjoamaan riittävän suuren siirtokaistan pitkillekin siirtoetäisyyksille, mutta kuitujen vetäminen on kallista. PON-verkot ovat kustannuksiltaan edullinen ratkaisu kuituyhteyden ulottamiseksi myös koteihin.

International audience; Broadband passive optical networks (PONs) share a single optical fiber transmission system between several customers. A dynamic bandwidth allocation (DBA) is used to avoid collisions for upstream traffic. An ideal DBA should support both committed bandwidth and best effort services while efficiently utilising the available bandwidth and providing isolation between customers in order to offer fair access to resources. In the present paper, we assume that each customer negotiates traffic profiles for its upstream committed bandwidth traffic. We show that a DBA that does not take into account conformance to the negotiated traffic profiles cannot isolate compliant customers from non-compliant customers, leading to QoS degradations for compliant customers. We then propose a framework for taking into account the traffic conformance within the DBA. This study is illustrated by an original, priority based DBA designed for Ethernet optical networks (EPONs).