56 research outputs found

    On greening optical access networks

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    With the remarkable growth of fiber-based services, the number of FTTx subscribers has been dramatically increasing in recent years. Owing to the environmental concern, reducing energy consumption of optical access networks has become an important issue for network designers. In Ethernet passive optical network (EPON), the optical line terminal (OLT) located at the central office broadcasts the downstream traffic to all optical network units (ONUs), each of which checks all arrival downstream packets to obtain those destined to itself. Since traffic of ONUs changes dynamically, properly defining the sleep mode for idle ONUs can potentially save a significant amount of energy. However, it is challenging to shut down an ONU receiver as the ONU needs to receive some downstream control packets to perform upstream transmission. In this framework, a novel sleep control scheme is proposed to address the downstream issue which can efficiently put ONU receivers to sleep. This dissertation further defines multiple levels of power saving in which the ONU disables certain functions based on the upstream and downstream traffic load. The proposed schemes are completely compatible with the multi-point control protocol (MPCP) and EPON standards. Elimination of the handshake process makes the sleep control schemes more efficient. Currently, OLTs also consume a significant amount of energy in EPON. Therefore, reducing energy consumption of OLT is as important as reducing energy consumption of ONUs; such requirement becomes even more urgent as OLT keeps increasing its provisioning data rate, and higher data rate provisioning usually implies higher energy consumption. Thus, a novel energy-efficient OLT structure, which guarantees services of end users with a smallest number of power-on OLT line cards, is proposed. More specifically, the number of power-on OLT line cards is adapted to the real-time incoming traffic. Also, to avoid service disruption resulted by powering off OLT line cards, a proper optical switch is equipped in OLT to dynamically configure the communications between OLT line cards and ONUs. By deploying a semi-Markov based technique, the performance characteristics of the sleep control scheme such as delay and energy-saving are theoretically analyzed. It is shown that, with proper settings of sleep control parameters, the proposed scheme can save a significant amount of energy in EPON

    Study of Bidirectional Broadband Passive Optical Network (BPON) Using EDFA

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    Optical line terminals (OLTs) and number of optical network units (ONUs) are two main parts of passive optical network (PON). OLT is placed at the central office of the service providers, the ONUs are located near to the end subscribers. When compared with point-to-point design, a PON decreases the number of fiber used and central office components required. Broadband PON (BPON), which is one type of PON, can support high-speed voice, data and video services to subscribers\u27 residential homes and small businesses. In this research, by using erbium doped fiber amplifier (EDFA), the performance of bi-directional BPON is experimented and tested for both downstream and upstream traffic directions. Ethernet PON (E-PON) and gigabit PON (G-PON) are the two other kinds of passive optical network besides BPON. The most beneficial factor of using BPON is it\u27s reduced cost. The cost of the maintenance between the central office and the users\u27 side is suitable because of the use of passive components, such as a splitter in the BPON architecture. In this work, a bidirectional BPON has been analyzed for both downstream and upstream cases by using bit error rate analyzer (BER). BER analyzers test three factors that are the maximum Q factor, minimum bit error rate, and eye height. In other words, parameters such as maximum Q factor, minimum bit error rate, and eye height can be analyzed utilized a BER tester. Passive optical components such as a splitter, optical circulator, and filters have been used in modeling and simulations. A 12th edition Optiwave simulator has been used in order to analyze the bidirectional BPON system. The system has been tested under several conditions such as changing the fiber length, extinction ratio, dispersion, and coding technique. When a long optical fiber above 40km was used, an EDFA was used in order to improve the quality of the signal

    The Design of FTTH Network

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    The aim of this thesis is to explain the problems of optical access networks with wavelength division multiplexers, main purpose is to demonstrate the difference between theoretical and real measurement. The work is divided into several thematic areas. The introduction outlines the basic of telecommunications, fiber optics lasers, single mode, multimode, lasers fibers cables & cores, splitters division multiplexing system, there are known solutions discussed fundamental wavelength multiplexes and their possible combinations. The following chapter deals with the active elements such as AON, PON, which are essential part xWDM systems such as optical lasers, detectors and amplifiers. Another chapter focuses on passive elements, which form a key part of the wavelength multiplex. Methods of measurement of WDM/PON networks are discussed in the following part. The next section describes the topology used active and passive optical networks. The penultimate part of the work consists of architecture & technology of xWDM such as GPON and WDM-PON networks and comparing their transmission parameters. The final part of the paper presents the results of practical experimental measurements of optical access networks with wavelengths division multiplex while these results are compared with the theoretical output & methods of Optical lost test, OTDR & LSPM, with advantage & disadvantage of every methods. The second part of practical is the draft to the connection resident housing units of 30 houses, boarding-house (10 rooms) and 2 shops, 20 km distant from exchange. With comparing the possibilities of two options- passive and active optical network- PON system – WDM- Wave multiplex. Suggest the possibility of measuring and monitoring the created network.The aim of this thesis is to explain the problems of optical access networks with wavelength division multiplexers, main purpose is to demonstrate the difference between theoretical and real measurement. The work is divided into several thematic areas. The introduction outlines the basic of telecommunications, fiber optics lasers, single mode, multimode, lasers fibers cables & cores, splitters division multiplexing system, there are known solutions discussed fundamental wavelength multiplexes and their possible combinations. The following chapter deals with the active elements such as AON, PON, which are essential part xWDM systems such as optical lasers, detectors and amplifiers. Another chapter focuses on passive elements, which form a key part of the wavelength multiplex. Methods of measurement of WDM/PON networks are discussed in the following part. The next section describes the topology used active and passive optical networks. The penultimate part of the work consists of architecture & technology of xWDM such as GPON and WDM-PON networks and comparing their transmission parameters. The final part of the paper presents the results of practical experimental measurements of optical access networks with wavelengths division multiplex while these results are compared with the theoretical output & methods of Optical lost test, OTDR & LSPM, with advantage & disadvantage of every methods. The second part of practical is the draft to the connection resident housing units of 30 houses, boarding-house (10 rooms) and 2 shops, 20 km distant from exchange. With comparing the possibilities of two options- passive and active optical network- PON system – WDM- Wave multiplex. Suggest the possibility of measuring and monitoring the created network.

    Major: Electronics and Communication Engineering

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    Today, information technology is strategically important to the goals and aspirations of the business enterprises, government and high-level education institutions – university. Universities are facing new challenges with the emerging global economy characterized by the importance of providing faster communication services and improving the productivity and effectiveness of individuals. New challenges such as provides an information network that supports the demands and diversification of university issues. A new network architecture, which is a set of design principles for build a network, is one of the pillar bases. It is the cornerstone that enables the university’s faculty, researchers, students, administrators, and staff to discover, learn, reach out, and serve society. This thesis focuses on the network architecture definitions and fundamental components. Three most important characteristics of high-quality architecture are that: it’s open network architecture; it’s service-oriented characteristics and is an IP network based on packets. There are four important components in the architecture, which are: Services and Network Management, Network Control, Core Switching and Edge Access. The theoretical contribution of this study is a reference model Architecture of University Campus Network that can be followed or adapted to build a robust yet flexible network that respond next generation requirements. The results found are relevant to provide an important complete reference guide to the process of building campus network which nowadays play a very important role. Respectively, the research gives university networks a structured modular model that is reliable, robust and can easily grow

    Solution strategies of service fulfilment Operation Support Systems for Next Generation Networks

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    Suomalainen operatiivisten tukijärjestelmien toimittaja tarjoaa ratkaisuja palvelujen aktivointiin, verkkoresurssien hallintaan ja laskutustietojen keruuseen. Nämä ratkaisut ovat pääosin käytössä langattomissa verkoissa. Tässä tutkimuksessa arvioidaan kyseisten ratkaisujen soveltuvuutta palvelutoimitusprosessien automatisointiin tulevaisuuden verkkoympäristöissä. Tarkastelun kohteena ovat runko- ja pääsyverkkojen kiinteät teknologiat, joiden suosio saavuttaa huippunsa seuraavan 5-10 vuoden aikana. Näissä verkoissa palvelujen, kuten yritys-VPN:n tai kuluttajan laajakaistan, aktivointi vaatii monimutkaisen toimitusprosessin, jonka tueksi tarvitaan ensiluokkaista tukijärjestelmää. Teknologiakatsauksen jälkeen tutkimuksessa verrataan viitteellistä tuoteportfoliota saatavilla oleviin operatiivisten tukijärjestelmien arkkitehtuurisiin viitekehyksiin, ja analysoidaan sen soveltuvuus tulevaisuuden verkkoympäristöjen palvelutoimitusprosessin automatisointiin. Myös palvelutoimitusprosessien automatisointiin soveltuvien tukijärjestelmien markkinatilanne arvioidaan, ja tämän perusteella tutkitaan optimaalisinta sovellusstrategiaa. Lopulta voidaan päätellä, että tuoteportfoliolle parhaiten soveltuvin sovellusalue on kuluttajan laajakaistan, ja siihen liittyvien kehittyneempien IP-palveluiden palvelutoimitusprosessien automatisointi.A Finnish Operation Support Systems (OSS) vendor provides solutions for service activation, network inventory and event mediation. These solutions have mostly been deployed in mobile environments. In this thesis it will be studied how feasible it is to use similar solutions for service fulfilment in Next Generation Networks (NGN). NGN is a broad term that describes some key architectural evolutions in telecommunication core and access networks that will be deployed over the next 5 to 10 years. In these networks service, e.g. Triple Play or Virtual Private Network (VPN), activations require an extensive service fulfilment process that must be supported by first-class OSS. After introducing the NGN technologies, the research compares a reference product portfolio to available service fulfilment frameworks and evaluates the applicability. The study analyses the current state of service fulfilment OSS markets and evaluates various solution strategies. Eventually it will be concluded that the most interesting and adequate solution scenario is residential broadband, including value-added IP services
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