Integration of Hybrid Passive Optical Networks (PON) with Radio over Fiber (RoF)

A cost effective, robust, and high capacity access network necessitated to meet the mounting customer demands for bandwidth-desirous services. A remarkable evolution of access networks is observed both in wired and wireless, predominantly driven by ever-changing bandwidth requirements. A wireless connection releases the end user from the restrictions of a physical link to a network that results in mobility, flexibleness, and ease of use. Whereas, optical networks offer immense amount of bandwidth that appease the most bandwidth voracious customers compared to bandwidth limited wireless networks. The integration of wired and wireless domains in the access landscape that presents a technical analysis of optical architectures suitable to support radio over fiber (RoF) is the objective of this chapter. Investigate the main trends that drive the merger of fiber and wireless technologies in access networks. Moreover, study the primary terms and the particular transmission features of integrated fiber-radio links to form a well-defined classification of hybrid systems and techniques. This work also recognizes the major problems for realization of RoF systems and examines the limitation, advantages, and diversity of integrated RoF-PON technology

Optical fiber transmission systems for in-door next generation broadband access network.

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London.This thesis investigates the generation and radio-over-fibre (RoF) transport of unlicensed 60 GHz millimetre-wave (mm-wave) frequency band. The investigated benefits of transmission schemes applicable for the mm-wave generation include optical carrier suppression (OCS), optical frequency multiplication (OFM) and remote heterodyne detection (RHD). For the in-door cabling of the mm-wave transmission, a low-cost polymer optical fibre (POF) along with bend-insensitive single mode fibre (BI-SMF) has been investigated for short-range networks. Transporting mm-wave generated signals over POF and BI-SMF cables based on OCS scheme showed results with the highest spectral efficiency and least inter-symbol interference over a 2.5 Gbit/s data delivery. Based on this thesis analysis, OCS simulation of POF showed the most reliable power penalty performance and receiver sensitivity at 30-m whilst the BI-SMF fiber produced equal observations at 150-m and more. In observing the free space links of delivering the RoF signal, the attenuation on the received signal power for both POF and BI-SMF was insignificant but expected, as the simulation assumed complete and total collimation of the light beams onto the aperture of the photodetector. OCS scheme for mm-wave generation and transport was explored based on the cost effectiveness of using one external modulator compared to other generation schemes that utilised more than one external modulator. OFM scheme was simulated to transport LTE and Wi-Fi signals along with 60 GHz RF band through both SMF and MMF-POF/BI-SMF cables. OFM transport scheme produced the highest attenuation on LTE, Wi-Fi and mm-wave signals carrying 100 Mbit/s data as simulated POF lengths increased. The best performance POF length was observed at 10-m. The application of offset launch technique at the coupling of SMF and POF showed insignificant improvement on signal bandwidth. The free space OFM transmission also demonstrated negligible change to the received signal power. This reinforces the attributes of deploying OWC system in an in-door environment. In other investigation, the simulated successful delivery of mm-wave signal using RHD scheme modulated and transported 10 Gbit/s data signal over POF and BI-SMF cables. Additional observed unrecorded result also showed BI-SMF cable maintained a 2% reduction of received power for 450-m fiber cable from 150-m. The attributes to RHD includes its low operating power system application and delivery of localised 60 GHz signal for uplink RoF transmission. The conceptualised design of Gigabit data delivery for indoor customer applications either through POF or BI-SMF cable, transporting various wireless channels has been presented in this thesis for the design of a robust next generation Broadband access network to reinforce the fiber-inside-the-home (FiTH) deployment

Dynamic bandwidth management with service differentiation over ethernet passive optical networks

Ethernet passive optical networks (EPONs) address the first mile of the communication infrastructure between the service provider central offices and the customer sites. As a low-cost, high speed technology, EPONs are deemed as the solution to the bottleneck problem of the broadband access network. A major feature of EPONs is the utility of a shared upstream channel among the end users. Only a single optical network unit (GNU) may transmit during a timeslot to avoid data collisions. In order to provide diverse quality of service (QoS), the bandwidth management of the upstream channel is essential for the successful implementation of EPONs, and thus, an efficient medium access control is required to facilitate statistical multiplexing among local traffics. This dissertation addresses the upstream bandwidth allocation over EPONs. An efficient mechanism, i.e., limited sharing with traffic prediction (LSTP), has been proposed to arbitrate the upstream bandwidth among ONUs. The MultiPoint Control Protocol (MPCP) messages, which are stipulated by the IEEE 802.3ah Ethernet in the First Mile (EFM) Task Force, are adopted by LSTP to facilitate the dynamic bandwidth negotiation between an GNU and the OLT. The bandwidth requirement of an ONU includes the already enqueued frames and the predicted incoming frames during the waiting time. The OLT arbitrates the bandwidth assignment based on the queue status report from an GNU, the traffic prediction, and the agreed service contract. With respect to the performance evaluation, theoretical analysis on the frame loss, the frame delay, and the queue length has been conducted. The quantitative results demonstrate that 1) the innovative LSTP mechanism dynamically allocates the upstream bandwidth among multiple ONUs; 2) the traffic predictor at the OLT delivers satisfactory prediction for the bursty self-similar traffic, and thereby, contributing to the reduction of frame loss, frame delay, and queue length; and 3) the bandwidth arbitration at the OLT effectively restricts the aggressive bandwidth competition among ONUs by adopting the service level agreement (SLA) parameter as the upper bound. Aside from analysis, the LSTP mechanism has been substantiated by experimental simulations. In order to differentiate the service provisioning among diverse users, LSTP is further enhanced with the support of dynamic bandwidth negotiation based on multiple queues. The incoming traffics are first classified into three classes, and then enqueued into the corresponding queues. A traffic predictor is dedicated to one class of traffic from an GNU. Service differentiation among classes are provided by the combination of queuing and scheduling at the GNU side. At the OLT side, the bandwidth allocation for each class of traffic is based on the reported queue status and the traffic prediction, and is upper-bounded by the SLA parameter. Experimental simulations have justified the feasibility of providing service differentiation over the broadband EPONs

Optisen liityntäverkon ohjelmoitavien logiikkapiirien ohjelmoinnin suunnittelu

Tiedonsiirtoverkkojen rakenne elää muutoksen aikaa. Perinteisesti data-, puhelin- ja laajakaistaliikenne on siirretty erillisissä verkoissa, joiden samanaikainen ylläpitäminen tuottaa ylimääräisiä kustannuksia operaattoreille. Lisäksi uudet interaktiiviset palvelut vaativat toimiakseen sellaista palvelunlaatua, jota nykyiset tiedonsiirtoverkot eivät kykene tarjoamaan. Näiden epäkohtien johdosta tiedonsiirtoverkkojen kehityksessä tähdätään uusiin, entistä joustavampiin ja eri toiminnot yhdistäviin verkkoratkaisuihin, joissa tiedonsiirron palvelunlaadulla on entistä suurempi merkitys. Tällä hetkellä tiedonsiirtoverkkojen kokonaistiedonsiirtonopeuden kasvun pullonkaulatekijäksi on muodostunut kaupunkialueiden syöttöverkkojen monimutkaisuus, millä on suuri vaikutus myös tiedonsiirron palvelunlaatuun. TEKES-rahoitteisessa OAN-projektissa kehitetään uutta ja yksinkertaisempaa kaupunkialueen optista syöttöverkkoratkaisua, jolla alueen palvelunlaatua saataisiin parannettua. Tämä diplomityö on tehty osana OAN-projektia. Työssä kuvataan tiedonsiirtoverkkojen tämänhetkinen rakenne, tarkastellaan sen ongelmia ja tulevaisuuden kehityssuuntia, sekä esitetään pohdintojen pohjalta rakennettu malli tulevaisuuden tiedonsiirtoverkkojen rakenteelle. Työssä esitetään myös HDL-implementointiprosessiin kuuluvat työvaiheet sekä käydään läpi suunnitelma OAN-projektissa toteutettavan prototyypin ohjelmoitavien logiikkapiirien ohjelmaa varten

Orthogonal frequency division multiplexing for optical access networks

Orthogonal Frequency Division Multiplexing (OFDM) is a modulation scheme with numerous advantages that has for years been employed as the leading physical interface in many wired and wireless communication systems. Recently, with advancements made in digital signal processing, there has been a surge of interest in applying OFDM techniques for optical communications. This thesis presents extensive research on optical OFDM and how it is being applied in access networks. With the aid of theoretical analysis, simulations and experiments, it is shown that the system performance of direct-detection optical OFDM (DD-OOFDM) in the presence of MZM non-linear distortion can be improved by proper biasing and selection of appropriate drive to the MZM. Investigations are conducted to illustrate how a variation in the number of subcarriers and the modulation format influences the sensitivity of the DD-OOFDM system to the MZM non-linear distortion. The possibility of improving the spectral efficiency by reduction of the width of the guard band is also investigated. This thesis also looks into the radio-over-fibre (RoF) transmission of Multiband OFDM UWB as a transparent and low-cost solution for distributing multi-Gbit/s data to end-users in FTTH networks. Due to relaxed regulatory requirements and the wide bandwidth available, UWB operation in the 60-GHz band is also considered for this FTTH application scenario. Four techniques for enabling MB-OFDM UWB RoF operation in the 60-GHz band are experimentally demonstrated. The impacts of various parameters on the performance of the techniques as well as the limitations imposed by fibre distribution are illustrated. Finally, a digital pre-distorter is proposed for compensating for the MZM non-linearity. Experimental demonstration of this digital pre-distortion in an UWB over fibre transmission system shows an increased tolerance to the amplitude of the driving OFDM signal as well as an increase in the optimum modulation index of the OFDM signal

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

Reconfigurable remote nodes for hybrid passive optical networks

Mestrado em Engenharia Electrónica e TelecomunicaçõesO presente documento tem por objectivo demonstrar, analisar e optimizar nós remotos passivos para redes ópticas passivas baseadas numa topologia de anel de dupla fibra com multiplexagem no comprimento de onda onde estão penduradas árvores mono fibra baseadas na multiplexagem no tempo. A rede ‘Scalable Advanced Ring-based passive Dense Access Network Architecture’ (SARDANA) baseada nesta topologia é apresentada e demonstrada. Na rede SARDANA a interligação entre o anel e as árvores é realizada pelo intermédio de um nó especial denominado de nó remoto. Esse nó remoto é um elemento fundamental para o funcionamento, resiliência e escalabilidade da rede. Neste documento são apresentadas e comparadas diferentes topologias para a implementação desse nó remoto. É também apresentada a reconfigurabilidade remota desses mesmos nós remotos através de módulos de conversão energética e controlo, implementada nos nós remotos. Um factor importante para a optimização dos nós remotos é a amplificação remota realizada por intermédio de fibras dopadas de érbio pelo que o seu estudo é também apresentado. Finalmente é demonstrado um protótipo de um nó remotamente reconfigurado e eficiente. ABSTRACT: The objective of this document is to demonstrate, analyze and optimize remote nodes for passive optical networks based on double fiber ring multiplexed in wavelength connected to single fiber trees multiplexed in time. The network ‘Scalable Advanced Ring-based passive Dense Access Network Architecture’ (SARDANA) based on this topology is presented and demonstrated. In the SARDANA network the interconnection between the ring and the trees is done by means of a special node, the remote node. This node is a fundamental element to the operation, resiliency and scalability of the network. This document presents and compares different topologies to the implementation of the remote node. Remotely reconfigurability of the remote nodes is also demonstrated by means of optical conversion and control modules. An important factor to the optimization of the remote nodes is the remote amplification done by means of erbium doped fibers being presented the analysis of the amplifier. Finally is demonstrated a prototype of a node remotely reconfigured and efficient

Optimization Methods for Optical Long-Haul and Access Networks

Optical communications based on fiber optics and the associated technologies have seen remarkable progress over the past two decades. Widespread deployment of optical fiber has been witnessed in backbone and metro networks as well as access segments connecting to customer premises and homes. Designing and developing a reliable, robust and efficient end-to-end optical communication system have thus emerged as topics of utmost importance both to researchers and network operators. To fulfill these requirements, various problems have surfaced and received attention, such as network planning, capacity placement, traffic grooming, traffic scheduling, and bandwidth allocation. The optimal network design aims at addressing (one or more of) these problems based on some optimization objectives. In this thesis, we consider two of the most important problems in optical networks; namely the survivability in optical long-haul networks and the problem of bandwidth allocation and scheduling in optical access networks. For the former, we present efficient and accurate models for availability-aware design and service provisioning in p-cycle based survivable networks. We also derive optimization models for survivable network design based on p-trail, a more general protection structure, and compare its performance with p-cycles. Indeed, major cost savings can be obtained when the optical access and long-haul subnetworks become closer to each other by means of consolidation of access and metro networks. As this distance between long-haul and access networks reduces, and the need and expectations from passive optical access networks (PONs) soar, it becomes crucial to efficiently manage bandwidth in the access while providing the desired level of service availability in the long-haul backbone. We therefore address in this thesis the problem of bandwidth management and scheduling in passive optical networks; we design efficient joint and non-joint scheduling and bandwidth allocation methods for multichannel PON as well as next generation 10Gbps Ethernet PON (10G-EPON) while addressing the problem of coexistence between 10G-EPONs and multichannel PONs