Multichannel optical access networks : design and resource management

At present there is a strong worldwide push towards bringing fiber closer to individual homes and businesses. The next evolutionary step is the cost-effective all-optical integration of fiber-based access and metro networks. STARGATE [1] is an all-optical access-metro architecture which does not rely on costly active devices, e.g., Optical Cross-Connects (OXCs) or Fixed Wavelength Converters (FWCs), and allow low-cost PON technologies to follow low-cost Ethernet technologies from EPON access into metro networks, resulting in significantly reduced cost and complexity. It makes use of an overlay island of transparency with optical bypassing capabilities. In this thesis we first propose Optical Network Unit (ONU) architectures, and discuss several technical challenges, which allow STARGATE EPONs (SG-EPONs) to evolve in a pay-as-you-grow manner while providing backward compatibility with legacy infrastructure and protecting previous investment. Second, and considering all the hardware constraints, we present the corresponding dynamic bandwidth allocation algorithm for effective resource management in these networks and investigate their performances (delay, throughput) through simulation experiments. We further investigate the problem of transmission grant scheduling in multichannel optical access networks using a scheduling theoretic approach. We show that the problem can be modeled as an Open Shop and we formulate the joint scheduling and wavelength assignment problem as a Mixed Integer Linear Program (MJLP) whose objective is to reduce the length of a scheduling period. Since the problem is known to be NP-hard, we introduce a Tabu Search based heuristic for solving the joint problem. Different other heuristics are also considered and their performances are compared with those of Tabu and MILP. Results indicate that by appropriately scheduling transmission grants and assigning wavelengths, substantial and consistent improvements may be obtained in the network performance. For example, Tabu shows a reduction of up to 29% in the schedule length with substantial reduction in channel idle gaps yielding to both higher channel utilization and lower queuing delays. Additionally, when the number of channels in the network is not small, the benefits of performing appropriate wavelength assignment, together with transmission scheduling, are observed and discussed. We further perform a packet-level simulation on the considered network to study the benefits of efficient grant scheduling; significant improvements are shown both in terms of system utilization and packet queuing delays

Next Generation Optical Access Networks: from TDM to WDM

Postprint (author’s final draft

Next Generation Optical Access Networks: from TDM to WDM

Postprint (author’s final draft

New dynamic bandwidth allocation algorithm analysis: DDSPON for ethernet passive optical networks

This project aims to present the state of the art in Dynamic Bandwidth Allocation (DBA) solutions, as well as the study and evaluation of one proposal of DBA algorithm: the Distributed Dynamic Scheduling for EPON (DDSPON), which is the UPC contribution to the research in scheduling algorithms for EPON

Resource management research in ethernet passive optical networks

The last decades, we have witnessed different phenomenology in the telecommunications sector. One of them is the widespread use of the Internet, which has brought a sharp increase in traffic, forcing suppliers to continuously expand the capacity of networks. In the near future, Internet will be composed of long-range highspeed optical networks; a number of wireless networks at the edge; and, in between, several access technologies. Today one of the main problems of the Internet is the bottleneck in the access segment. To address this issue the Passive Optical Networks (PONs) are very likely to succeed, due to their simplicity, low-cost, and increased bandwidth. A PON is made up of fiber optic cabling and passive splitters and couplers that distribute an optical signal to connectors that terminate each fiber segment. Among the different PON technologies, the Ethernet-PON (EPON) is a great alternative to satisfy operator and user needs, due to its cost, flexibility and interoperability with other technologies. One of the most interesting challenges in such technologies relates to the scheduling and allocation of resources in the upstream (shared) channel, i.e., the resource management. The aim of this thesis is to study and evaluate current contributions and propose new efficient solutions to address the resource management issues mainly in EPON. Key issues in this context are future end-user needs, quality of service (QoS) support, energy-saving and optimized service provisioning for real-time and elastic flows. This thesis also identifies research opportunities, issue recommendations and proposes novel mechanisms associated with access networks based on optical fiber technologies.Postprint (published version

Mecanismos para gerenciamento de banda passante em redes ópticas passivas Ethernet com clientes locatários de múltiplas unidades ópticas de redes

Orientador: Nelson Luis Saldanha da FonsecaDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: As atuais redes de acesso banda larga à Internet necessitam dar suporte às altas demandas de diversas aplicações tais como voz sobre IP (VoIP), streaming de vídeo UHD, videoconferência, internet das coisas (IoT) e jogos interativos. A tecnologia de redes ópticas passivas (PONs) é considerada promissora para fornecer alta capacidade de acesso com um custo-benefício aceitável. Existem duas diferentes tecnologias que disputam o mercado das redes ópticas; Ethernet PON (EPON) e Gigabit Capable PON(GPON). Devido ao alto custo de aquisição e manutenção de uma infraestrutura PON, muitas empresas (clientes) recorrem a fornecedores de infraestrutura (InP) para reduzir os altos custo, por meio do aluguel de uma porção dos recursos da PON. Esses clientes podem ser, por exemplo, operadores de rede móvel ou provedores de serviços virtuais, que podem adquirir múltiplas unidades da rede óptica (ONU) conectadas em uma única PON. Essa facilidade de alugar múltiplas ONUs pode gerar problemas de balanceamento de carga entre ONUs, uma vez que os atuais algoritmos de alocação de banda passante (DBA) são capazes de garantir banda para uma única ONU. Consequentemente, picos de demanda de banda passante podem ultrapassar a banda garantida em algumas ONUs e, ao mesmo tempo, subutilizar a banda garantida em outras ONUs de um mesmo cliente. Nesta dissertação, aborda-se o problema de gerenciamento de largura de banda para clientes multi-ONU nas redes EPON. Propõe-se um algoritmo de alocação dinâmica de banda passante (DBA) (MOS-IPACT) para dar suporte ao contrato de serviço (SLA) para clientes com várias ONUs. O mecanismo proposto distribui a largura de banda agregada entre ONUs de um mesmo cliente, com o objetivo de melhorar a utilização da largura de banda. Além disso propõe-se um algoritmo DBA para EPONs (subMOSIPACT) com o objetivo de garantir banda passante em diferentes níveis de granularidade. Este algoritmo é fundamental para clientes multi-ONU e que oferecem diversos tipos de serviços. Por exemplo, um operador da rede virtual pode alugar as ONUs de um InP para oferecer serviços corporativos e residenciais. Introduz-se, também, um algoritmo DBA para EPONs (coopMOS-IPACT) que permite a cooperação entre clientes. O algoritmo proposto permite que clientes cooperativos compartilhem banda passante não utilizada a fim de aumentar a banda disponível para alocação mas sem afetar seus SLAs individuais. Os resultados mostram que os três algoritmos propostos são capazes de garantir banda passante para clientes multi-ONU, mesmo em condições de tráfego desbalanceadas; Além de garantir banda passante em diferentes níveis de granularidade aumentando o suporte aos requisitos de qualidade de serviço (QoS). Resultados derivados por simulação mostraram que os algoritmos distribuem eficientemente a largura de banda entre os clientes multi-ONU bem como para clientes convencionais que possuem uma única ONU. Por fim, este trabalho mostra os benefícios do modelo de clientes cooperativos para aumentar a largura de banda disponívelAbstract: Current broadband access networks need to support the Quality of Service (QoS) requirements of diverse application such as voice over IP (VoIP), ultra-high video streaming, video conferencing, Internet of Things (IoT) and interactive gaming. Passive Optical Networks (PONs) is considered a promising solution to provides high access capacity with acceptable cost-benefit. Two different technologies share the optical access networks market: Ethernet PON (EPON) and Gigabit Capable PON (GPON). However, the deployment of PON infrastructure involves significant costs. On the other hand, Infrastructure Provider (InP) can alleviate these costs by leasing their PONs to several enterprises (customers). These customers can be Mobile Network Operators (MNOs), multi-site enterprises, or virtual service providers. New scenarios are envisioned in which customers owning multiple Optical Network Units (ONUs) (multi-ONUs customers) are connected to a single PON. However, current EPON Dynamic Bandwidth Allocation (DBA) algorithms are able to support only guaranteed bandwidth for individual ONUs. Consequently, peaks of bandwidth demand may surpass the guaranteed bandwidth for some ONUs and, at the same time, underutilize the bandwidth in other ONUs of a multi-ONU customer. In this work, the bandwidth management problem for multi-ONU customers in EPON network is addressed. This dissertation proposes a mechanisms for the support of multiONU Service Level Agreements (SLA) in DBA algorithms for EPONs. The proposed DBA algorithms (MOS-IPACT) allows customers owning multiple ONUs to redistribute the aggregated bandwidth of the group of ONUs to better balance the bandwidth utilization. This dissertation also proposes a DBA algorithm for EPON networks (subMOS-IPACT) with the objective of assuring bandwidth at different levels of granularity. This algorithm is quite important for multi-ONU customers offering diverse type of services. For example, a virtual network operator can lease ONUs from an InP to offer enterprise and residential services to its client.This work also introduce a DBA algorithm for EPONs (coopMOS-IPACT), which allows cooperation between customers. The proposed DBA algorithm allows cooperative customers share the unused bandwidth without affecting their individual multi-ONU SLAs. Results show that the three proposed Dynamic Bandwidth Allocation (DBA) algorithms are able to guarantee bandwidth for multi-Optical Network Unit (ONU) customers even in unbalancing traffic conditions. Furthermore, assuring bandwidth at different levels of granularity improves the Quality of Service (QoS) providing. Simulation results showed that the mechanisms efficiently distributes bandwidth between multi-ONU customers and traditional customers owning a single ONU. Finally, this work show the benefits of cooperative customers model in order to increase the available bandwidthMestradoCiência da ComputaçãoMestre em Ciência da Computação132308/2016-9CNP

Optical Network Design, Modelling and Performance Evaluation for the Upgraded LHC at CERN

This thesis considers how advances in optical network and optoelectronic technologies may be utilised in particle physics applications. The research is carried out within a certain framework; CERN's Large Hadron Collider (LHC) upgrade. The focus is on the upgrade of the "last-tier" data links, those residing between the last information-processing stage and the accelerator. For that purpose, different network architectures, based on the Passive Optical Network (PON) architectural paradigm, are designed and evaluated. Firstly, a Time-Division Multiplexed (TDM) PON targeting timing, trigger and control applications is designed. The bi-directional, point-to-multipoint nature of the architecture leads to infrastructure efficiency increase. A custom protocol is developed and implemented using FPGAs. It is experimentally verified that the network design can deliver significantly higher data rate than the current infrastructure and meet the stringent latency requirements of the targeted application. Consequently, the design of a network that can be utilised to transmit all types of information at the upgraded LHC, the High-Luminosity LHC (HL-LHC) is discussed. The most challenging requirement is that of the high upstream data rate. As WDM offers virtual point-to-point connectivity, the possibility of using a Wavelength-Division Multiplexed (WDM) PON is theoretically investigated. The shortcomings of this solution are identified; these include high cost and complexity, therefore a simpler architecture is designed. This is also based on the PON paradigm and features the use of Reflective Electroabsorption Modulators (REAM) at the front-end (close to the particle collision point). Its performance is experimentally investigated and shown to meet the requirements of a unified architecture at the HL-LHC from a networking perspective. Finally, since the radiation resistance of optoelectronic components used at the front-end is of major importance, the REAM radiation hardness is experimentally investigated. Their radiation resistance limits are established, while new insights into the radiation damage mechanism are gained

Telecommunication Systems

This book is based on both industrial and academic research efforts in which a number of recent advancements and rare insights into telecommunication systems are well presented. The volume is organized into four parts: "Telecommunication Protocol, Optimization, and Security Frameworks", "Next-Generation Optical Access Technologies", "Convergence of Wireless-Optical Networks" and "Advanced Relay and Antenna Systems for Smart Networks." Chapters within these parts are self-contained and cross-referenced to facilitate further study

Journal of Telecommunications and Information Technology, 2009, nr 1

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