69 research outputs found

    Handover management for hybrid satellite/terrestrial networks

    Get PDF
    9 pagesInternational audienceInitially envisaged to support handover between different wireless 802.x network technologies, the IEEE 802.21 standard also appears as the good candidate for handover management in future integrated satellite / terrestrial systems. This paper presents an analysis of how this standard could be implemented in the frame of a realistic scenario and taking into account the current trends in wireless network and mobility architectures. Our solution is then evaluated by means of emulation over a DVB-RCS representative testbed, and based on an experimental MIH implementation. We finally show that seamless handover can nearly be achieved with very short service outages

    Design and implementation of the OFELIA FP7 facility: The European OpenFlow testbed

    Get PDF
    The growth of the Internet in terms of number of devices, the number of networks associated to each device and the mobility of devices and users makes the operation and management of the Internet network infrastructure a very complex challenge. In order to address this challenge, innovative solutions and ideas must be tested and evaluated in real network environments and not only based on simulations or laboratory setups. OFELIA is an European FP7 project and its main objective is to address the aforementioned challenge by building and operating a multi-layer, multi-technology and geographically distributed Future Internet testbed facility, where the network itself is precisely controlled and programmed by the experimenter using the emerging OpenFlow technology. This paper reports on the work done during the first half of the project, the lessons learned as well as the key advantages of the OFELIA facility for developing and testing new networking ideas. An overview on the challenges that have been faced on the design and implementation of the testbed facility is described, including the OFELIA Control Framework testbed management software. In addition, early operational experience of the facility since it was opened to the general public, providing five different testbeds or islands, is described

    Linking session based services with transport plane resources in IP multimedia subsystems.

    Get PDF
    The massive success and proliferation of Internet technologies has forced network operators to recognise the benefits of an IP-based communications framework. The IP Multimedia Subsystem (IMS) has been proposed as a candidate technology to provide a non-disruptive strategy in the move to all-IP and to facilitate the true convergence of data and real-time multimedia services. Despite the obvious advantages of creating a controlled environment for deploying IP services, and hence increasing the value of the telco bundle, there are several challenges that face IMS deployment. The most critical is that posed by the widespread proliferation ofWeb 2.0 services. This environment is not seen as robust enough to be used by network operators for revenue generating services. However IMS operators will need to justify charging for services that are typically available free of charge in the Internet space. Reliability and guaranteed transport of multimedia services by the efficient management of resources will be critical to differentiate IMS services. This thesis investigates resource management within the IMS framework. The standardisation of NGN/IMS resource management frameworks has been fragmented, resulting in weak functional and interface specifications. To facilitate more coherent, focused research and address interoperability concerns that could hamper deployment, a Common Policy and Charging Control (PCC) architecture is presented that defines a set of generic terms and functional elements. A review of related literature and standardisation reveals severe shortcomings regarding vertical and horizontal coordination of resources in the IMS framework. The deployment of new services should not require QoS standardisation or network upgrade, though in the current architecture advanced multimedia services are not catered for. It has been found that end-to-end QoS mechanisms in the Common PCC framework are elementary. To address these challenges and assist network operators when formulating their iii NGN strategies, this thesis proposes an application driven policy control architecture that incorporates end-user and service requirements into the QoS negotiation procedure. This architecture facilitates full interaction between service control and resource control planes, and between application developers and the policies that govern resource control. Furthermore, a novel, session based end-to-end policy control architecture is proposed to support inter-domain coordination across IMS domains. This architecture uses SIP inherent routing information to discover the routes traversed by the signalling and the associated routes traversed by the media. This mechanism effectively allows applications to issue resource requests from their home domain and enable end-to-end QoS connectivity across all traversed transport segments. Standard interfaces are used and transport plane overhaul is not necessary for this functionality. The Common PCC, application driven and session based end-to-end architectures are implemented in a standards compliant and entirely open source practical testbed. This demonstrates proof of concept and provides a platform for performance evaluations. It has been found that while there is a cost in delay and traffic overhead when implementing the complete architecture, this cost falls within established criteria and will have an acceptable effect on end-user experience. The open nature of the practical testbed ensures that all evaluations are fully reproducible and provides a convenient point of departure for future work. While it is important to leave room for flexibility and vendor innovation, it is critical that the harmonisation of NGN/IMS resource management frameworks takes place and that the architectures proposed in this thesis be further developed and integrated into the single set of specifications. The alternative is general interoperability issues that could render end-to-end QoS provisioning for advanced multimedia services almost impossible

    Sistema para gestão remota de redes experimentais

    Get PDF
    Mestrado em Engenharia de Computadores e TelemáticaA Internet e as redes no seu geral estão cada vez mais presentes no nosso quotidiano. No entanto, o seu crescente uso destaca também algumas das suas limitações, levando os investigadores de redes a criarem novas soluções, numa tentativa de preverem e resolverem problemas que daí possam advir. O desenvolvimento destas soluções implica que sejam realizados testes exaustivos antes que estas se tornem aptas para o uso das massas. Podem ser adoptadas diversas abordagens para a realização destes testes. Simulações são importantes como uma primeira aproximação, contudo, não conseguem captar a dinâmica e a imprevisibilidade de um ambiente real. A emulação surge como alternativa, tentando colmatar essa falha, no entanto, não é eficaz na reprodução de cenários mais complexos. A solução poderá passar pela criação de infra-estruturas dedicadas ao teste destas soluções, denominadas de redes experimentais, permitindo realizar uma avaliação mais profunda e fiável das mesmas. Contudo a sua construção envolve grandes custos e as infra-estruturas caem em desuso assim que é alcançado o produto final. É necessário desenvolver maneiras de instrumentalizar estas infra-estruturas, de forma a optimizar estes recursos para futuros testes. Esta dissertação centra-se nos problema evidenciados na criação destas redes de teste, estudando as existentes formas de gestão destas redes experimentais, bem como o seu uso optimizado com vista à criação de experiencias. Pretende-se assim desenvolver no âmbito desta tese, uma ferramenta que permita aos utilizadores criarem e usarem facilmente e de forma eficiente uma rede experimental.The Internet, as with networks in general, is increasingly present in our everyday lives. However, its use also highlights some of their limitations, leading researchers to create new network solutions in an attempt to anticipate and solve problems that may arise. These solutions require exhaustive tests before they become eligible for production. Several approaches can be taken to conduct such tests. Simulations are important as first approximations; however, they fail to capture the dynamics and unpredictability of a real environment. Emulations present an alternative, but fail to reproduce more complex scenarios. Experimentation facilities must therefore be deployed, to achieve a higher level of realism. These facilities, also referred as testbeds, involve high-complexity deployment and operation, falling into disuse once they arrive at a final product. Methods of managing these infrastructures must be developed in order to avoid this waste of resources for future tests. This dissertation focuses on the problems inherent to the management of these facilities, with a focus on their users. Different approaches in network testing must be studied and the different methodologies on experimentation must be collected. An application is developed to address this problem, enabling users to create their experiments and collect results in both an organized and effective manner

    New Challenges in Quality of Services Control Architectures in Next Generation Networks

    Get PDF
    A mesura que Internet i les xarxes IP s'han anat integrant dins la societat i les corporacions, han anat creixent les expectatives de nous serveis convergents així com les expectatives de qualitat en les comunicacions. Les Next Generation Networks (NGN) donen resposta a les noves necessitats i representen el nou paradigma d'Internet a partir de la convergència IP. Un dels aspectes menys desenvolupats de les NGN és el control de la Qualitat del Servei (QoS), especialment crític en les comunicacions multimèdia a través de xarxes heterogènies i/o de diferents operadors. A més a més, les NGN incorporen nativament el protocol IPv6 que, malgrat les deficiències i esgotament d'adreces IPv4, encara no ha tingut l'impuls definitiu.Aquesta tesi està enfocada des d'un punt de vista pràctic. Així doncs, per tal de poder fer recerca sobre xarxes de proves (o testbeds) que suportin IPv6 amb garanties de funcionament, es fa un estudi en profunditat del protocol IPv6, del seu grau d'implementació i dels tests de conformància i interoperabilitat existents que avaluen la qualitat d'aquestes implementacions. A continuació s'avalua la qualitat de cinc sistemes operatius que suporten IPv6 mitjançant un test de conformància i s'implementa el testbed IPv6 bàsic, a partir del qual es farà la recerca, amb la implementació que ofereix més garanties.El QoS Broker és l'aportació principal d'aquesta tesi: un marc integrat que inclou un sistema automatitzat per gestionar el control de la QoS a través de sistemes multi-domini/multi-operador seguint les recomanacions de les NGN. El sistema automatitza els mecanismes associats a la configuració de la QoS dins d'un mateix domini (sistema autònom) mitjançant la gestió basada en polítiques de QoS i automatitza la negociació dinàmica de QoS entre QoS Brokers de diferents dominis, de forma que permet garantir QoS extrem-extrem sense fissures. Aquesta arquitectura es valida sobre un testbed de proves multi-domini que utilitza el mecanisme DiffServ de QoS i suporta IPv6.L'arquitectura definida en les NGN permet gestionar la QoS tant a nivell 3 (IP) com a nivell 2 (Ethernet, WiFi, etc.) de forma que permet gestionar també xarxes PLC. Aquesta tesi proposa una aproximació teòrica per aplicar aquesta arquitectura de control, mitjançant un QoS Broker, a les noves xarxes PLC que s'estan acabant d'estandarditzar, i discuteix les possibilitats d'aplicació sobre les futures xarxes de comunicació de les Smart Grids.Finalment, s'integra en el QoS Broker un mòdul per gestionar l'enginyeria del tràfic optimitzant els dominis mitjançant tècniques de intel·ligència artificial. La validació en simulacions i sobre un testbed amb routers Cisco demostra que els algorismes genètics híbrids són una opció eficaç en aquest camp.En general, les observacions i avenços assolits en aquesta tesi contribueixen a augmentar la comprensió del funcionament de la QoS en les NGN i a preparar aquests sistemes per afrontar problemes del món real de gran complexitat.A medida que Internet y las redes IP se han ido integrando dentro de la sociedad y las corporaciones, han ido creciendo las expectativas de nuevos servicios convergentes así como las expectativas de calidad en las comunicaciones. Las Next Generation Networks (NGN) dan respuesta a las nuevas necesidades y representan el nuevo paradigma de Internet a partir de la convergencia IP. Uno de los aspectos menos desarrollados de las NGN es el control de la Calidad del Servicio (QoS), especialmente crítico en las comunicaciones multimedia a través de redes heterogéneas y/o de diferentes operadores. Además, las NGN incorporan nativamente el protocolo IPv6 que, a pesar de las deficiencias y agotamiento de direcciones IPv4, aún no ha tenido el impulso definitivo.Esta tesis está enfocada desde un punto de vista práctico. Así pues, con tal de poder hacer investigación sobre redes de prueba (o testbeds) que suporten IPv6 con garantías de funcionamiento, se hace un estudio en profundidad del protocolo IPv6, de su grado de implementación y de los tests de conformancia e interoperabilidad existentes que evalúan la calidad de estas implementaciones. A continuación se evalua la calidad de cinco sistemas operativos que soportan IPv6 mediante un test de conformancia y se implementa el testbed IPv6 básico, a partir del cual se realizará la investigación, con la implementación que ofrece más garantías.El QoS Broker es la aportación principal de esta tesis: un marco integrado que incluye un sistema automatitzado para gestionar el control de la QoS a través de sistemas multi-dominio/multi-operador siguiendo las recomendaciones de las NGN. El sistema automatiza los mecanismos asociados a la configuración de la QoS dentro de un mismo dominio (sistema autónomo) mediante la gestión basada en políticas de QoS y automatiza la negociación dinámica de QoS entre QoS brokers de diferentes dominios, de forma que permite garantizar QoS extremo-extremo sin fisuras. Esta arquitectura se valida sobre un testbed de pruebas multi-dominio que utiliza el mecanismo DiffServ de QoS y soporta IPv6. La arquitectura definida en las NGN permite gestionar la QoS tanto a nivel 3 (IP) o como a nivel 2 (Ethernet, WiFi, etc.) de forma que permite gestionar también redes PLC. Esta tesis propone una aproximación teórica para aplicar esta arquitectura de control, mediante un QoS Broker, a las noves redes PLC que se están acabando de estandardizar, y discute las posibilidades de aplicación sobre las futuras redes de comunicación de las Smart Grids.Finalmente, se integra en el QoS Broker un módulo para gestionar la ingeniería del tráfico optimizando los dominios mediante técnicas de inteligencia artificial. La validación en simulaciones y sobre un testbed con routers Cisco demuestra que los algoritmos genéticos híbridos son una opción eficaz en este campo.En general, las observaciones y avances i avances alcanzados en esta tesis contribuyen a augmentar la comprensión del funcionamiento de la QoS en las NGN y en preparar estos sistemas para afrontar problemas del mundo real de gran complejidad.The steady growth of Internet along with the IP networks and their integration into society and corporations has brought with it increased expectations of new converged services as well as greater demands on quality in communications. The Next Generation Networks (NGNs) respond to these new needs and represent the new Internet paradigm from the IP convergence. One of the least developed aspects in the NGNs is the Quality of Service (QoS) control, which is especially critical in the multimedia communication through heterogeneous networks and/or different operators. Furthermore, the NGNs natively incorporate the IPv6 protocol which, despite its shortcomings and the depletion of IPv4 addresses has not been boosted yet.This thesis has been developed with a practical focus. Therefore, with the aim of carrying out research over testbeds supporting the IPv6 with performance guarantees, an in-depth study of the IPv6 protocol development has been conducted and its degree of implementation and the existing conformance and interoperability tests that evaluate these implementations have been studied. Next, the quality of five implementations has been evaluated through a conformance test and the basic IPv6 testbed has been implemented, from which the research will be carried out. The QoS Broker is the main contribution to this thesis: an integrated framework including an automated system for QoS control management through multi-domain/multi-operator systems according to NGN recommendations. The system automates the mechanisms associated to the QoS configuration inside the same domain (autonomous system) through policy-based management and automates the QoS dynamic negotiation between peer QoS Brokers belonging to different domains, so it allows the guarantee of seamless end-to-end QoS. This architecture is validated over a multi-domain testbed which uses the QoS DiffServ mechanism and supports IPv6.The architecture defined in the NGN allows QoS management at level 3 (IP) as well as at level 2 (e.g. Ethernet, WiFi) so it also facilitates the management of PLC networks. Through the use of a QoS Broker, this thesis proposes a theoretical approach for applying this control architecture to the newly standardized PLC networks, and discusses the possibilities of applying it over the future communication networks of the Smart Grids.Finally, a module for managing traffic engineering which optimizes the network domains through artificial intelligence techniques is integrated in the QoS Broker. The validations by simulations and over a Cisco router testbed demonstrate that hybrid genetic algorithms are an effective option in this area.Overall, the advances and key insights provided in this thesis help advance our understanding of QoS functioning in the NGNs and prepare these systems to face increasingly complex problems, which abound in current industrial and scientific applications

    Optimización de problemas de varios objetivos desde un enfoque de eficiencia energética aplicado a redes celulares heterogéneas 5G usando un marco de conmutación de celdas pequeñas

    Get PDF
    This Ph.D. dissertation addresses the Many-Objective Optimization Problem (MaOP) study to reduce the inter-cell interference and the power consumption for realistic Centralized, Collaborative, Cloud, and Clean Radio Access Networks (C-RANs). It uses the Cell Switch-Off (CSO) scheme to switch-off/on Remote Radio Units (RRUs) and the Coordinated Scheduling (CS) technique to allocate resource blocks smartly. The EF1-NSGA-III (It is a variation of the NSGA-III algorithm that uses the front 1 to find extreme points at the normalization procedure extended in this thesis) algorithm is employed to solve a proposed Many-Objective Optimization Problem (MaOP). It is composed of four objective functions, four constraints, and two decision variables. However, the above problem is redefined to have three objective functions to see the performance comparison between the NSGA-II and EF1-NSGA-III algorithms. The OpenAirInterface (OAI) platform is used to evaluate and validate the performance of an indoor coverage system because most of the user-end equipment of next-generation cellular networks will be in an indoor environment. It constitutes the fastest growing 5G open-source platform that implements 3GPP technology on general-purpose computers, fast Ethernet transport ports, and Commercial-Off-The-Shelf (COTS) software-defined radio hardware. This document is composed of five contributions. The first one is a survey about testbed, emulators, and simulators for 4G/5G cellular networks. The second one is the extension of the KanGAL's NSGA-II code to implement the EF1-NSGA-III, adaptive EF1-NSGA-III (A-EF1-NSGA-III), and efficient adaptive EF1-NSGA-III (A2^2-EF1-NSGA-III). They support up to 10 objective functions, manage real, integer, and binary decision variables, and many constraints. The above algorithms outperform other works in terms of the Inverted Generational Distance (IGD) metric. The third contribution is the implementation of real-time emulation methodologies for C-RANs using a frequency domain representation in OAI. It improves the average computation time 10-fold compared to the time domain without using Radio Frequency hardware and avoids their uncertainties. The fourth one is the implementation of the Coordination Scheduling (CS) technique as a proof-of-concept to validate the advantages of frequency domain methodologies and to allocate resource blocks dynamically among RRUs. Finally, a many-objective optimization problem is defined and solved with evolutionary algorithms where diversity is managed based on crowded-distance and reference points to reduce the power consumption for C-RANs. The solutions obtained are considered to control the scheduling task at the Radio Cloud Center (RCC) and to switch RRUs.Este disertación aborda el estudio del problema de optimización de varios objetivos (MaOP) para reducir la interferencia entre células y el consumo de energía para redes de acceso de radio en tiempo real, colaborativas, en la nube y limpias (C-RAN). Utiliza el esquema de conmutacion de celdas (CSO) para apagar / encender unidades de radio remotas (RRU) y la técnica de programación coordinada (CS) para asignar bloques de recursos de manera inteligente. El algoritmo EF1-NSGA-III (es una variación del algoritmo NSGA-III que usa el primer frente de pareto para encontrar puntos extremos en el procedimiento de normalización extendido en esta tesis) se utiliza para resolver un problema de optimización de varios objetivos (MaOP) propuesto. Se compone de cuatro funciones objetivos, cuatro restricciones y dos variables de decisión. Sin embargo, el problema anterior se redefine para tener tres funciones objetivas para ver la comparación de rendimiento entre los algoritmos NSGA-II y EF1-NSGA-III. La plataforma OpenAirInterface (OAI) se utiliza para evaluar y validar el rendimiento de un sistema de cobertura en interiores porque la mayoría del equipos móviles de las redes celulares de próxima generación estarán en un entorno interior. Ella constituye la plataforma de código abierto 5G de más rápido crecimiento que implementa la tecnología 3GPP en computadoras de uso general, puertos de transporte Ethernet rápidos y hardware de radio definido por software comercial (COTS). Este documento se compone de cinco contribuciones. La primera es una estudio sobre banco de pruebas, emuladores y simuladores para redes celulares 4G / 5G. El segundo es la extensión del código NSGA-II de KanGAL para implementar EF1-NSGA-III, EF1-NSGA-III adaptativo (A-EF1-NSGA-III) y EF1-NSGA-III adaptativo eficiente (A 2 ^ 2 -EF1-NSGA-III). Admiten hasta 10 funciones objetivas, gestionan variables de decisión reales, enteras y binarias, y muchas restricciones. Los algoritmos anteriores superan a otros trabajos en términos de la métrica de distancia generacional invertida (IGD). La tercera contribución es la implementación de metodologías de emulación en tiempo real para C-RAN utilizando una representación de dominio de frecuencia en OAI. Mejora el tiempo de cálculo promedio 10 veces en comparación con el dominio del tiempo sin usar hardware de radiofrecuencia y evita sus incertidumbres. El cuarto es la implementación de la técnica de Programación de Coordinación (CS) como prueba de concepto para validar las ventajas de las metodologías de dominio de frecuencia y asignar bloques de recursos dinámicamente entre las RRU. Finalmente, un problema de optimización de muchos objetivos se define y resuelve con algoritmos evolutivos en los que la diversidad se gestiona en función de la distancia de crouding y los puntos de referencia para reducir el consumo de energía de las C-RAN. Las soluciones obtenidas controlan la tarea de programación en Radio Cloud Center (RCC) y conmutan las RRU.Proyecto personal: Redes celulares de próxima generaciónDoctorad

    Building the Future Internet through FIRE

    Get PDF
    The Internet as we know it today is the result of a continuous activity for improving network communications, end user services, computational processes and also information technology infrastructures. The Internet has become a critical infrastructure for the human-being by offering complex networking services and end-user applications that all together have transformed all aspects, mainly economical, of our lives. Recently, with the advent of new paradigms and the progress in wireless technology, sensor networks and information systems and also the inexorable shift towards everything connected paradigm, first as known as the Internet of Things and lately envisioning into the Internet of Everything, a data-driven society has been created. In a data-driven society, productivity, knowledge, and experience are dependent on increasingly open, dynamic, interdependent and complex Internet services. The challenge for the Internet of the Future design is to build robust enabling technologies, implement and deploy adaptive systems, to create business opportunities considering increasing uncertainties and emergent systemic behaviors where humans and machines seamlessly cooperate

    Design and implementation aspects of open source next generation networks (NGN) test-bed software toolkits

    Get PDF
    Informations- und Kommunikationstechnologien bilden seit langem das immer wichtiger werdende Rückgrat der weltweiten Wirtschaft und Telekommunikation, in der speziell Telekommunikationsnetze und -dienste einen elementaren Anteil tragen. Durch die Konvergenz von Telekommunikations- und Internettechnologien hat sich die Telekommunikationslandschaft in der letzten Dekade drastisch verändert. Bislang geschlossene Telekommunikationsumgebungen haben sich imWandel zum sogenannten Next Generation Network (NGN) hinsichtlich unterstützter Zugangsnetztechnologien und angebotener multimedialer Anwendungen sowie der eingesetzten Protokolle und Dienste zu komplexen, hochdynamischen, Multi-Service Infrastrukturen gewandelt. Die Kontrollschicht solcher NGNs ist dabei von übergeordneter Bedeutung, da diese zwischen den Zugangsnetzen und den Anwendungen sitzt. Der Einsatz und die Optimierung des IP-Multimedia Subsystem (IMS) wurde in diesem Kontext Jahrelang erforscht und diskutiert und es repräsentiert heute die weltweit anerkannte Kontrollplattform für feste und mobile Telekommunikationsnetze. Die Forschung an Protokollen und Diensten in diesen NGN Umgebungen ist aufgrund der Konvergenz von Technologien, Anwendungen und Business Modellen sowie der hohen Dynamik aber kurzen Innovationszyklen hochkomplex. Der frühzeitigen Zugang zu herstellerunabhängigen – aber dicht an der Produktwelt angelehnten - Validierungsinfrastrukturen, sogenannten offenen Technologietest-beds, kurz Test-beds, ist daher für Forschungs- und Entwicklungsabteilungen unerlässlich Die vorliegende Dissertation beschreibt die umfangreiche Forschungsarbeit des Autors auf dem Gebiet der offenen NGN Test-beds über die letzten neun Jahre und konzentriert sich dabei auf Entwurf, Entwicklung und Bereitstellung des Open Source IMS Core Projekt, das seit Jahren die Grundlage für eine Vielzahl von NGN Test-beds und zahllose NGN Forschungs- und Entwicklungsprojekte im akademischen als auch Industrienahen Umfeld rund um den Globus darstellt. Dabei wird ein großer Schwerpunkt auf die Anforderungen hinsichtlich Flexibilität, Leistung, Funktionalitätsumfang und Interoperabilität, sowie elementare Designprinzipien von Test-bedwerkzeugen gelegt. Die Arbeit beschreibt und bewertet darüberhinaus den Einsatz von Open Source Prinzipien und veranschaulicht die Vorteile dieses Ansatzes hinsichtlich Einfluss und Nachhaltigkeit der Forschung anhand des Aufbaus einer globalen Open Source IMS Core (OpenIMSCore) Forschungs-Community. Außerdem veranschaulicht die Arbeit zum Ende die Wiederverwendbarkeit der wesentlichen angewendeten Designprinzipien an anderen maßgeblich durch den Autor entwickelten Test-bed Werkzeugen, insbesondere dem Open Evolved Packet Core (OpenEPC) für die nahtlose Integration verschiedener Breitbandnetztechnologien.Information and Communication Technologies provide for a long time already the backbone of telecommunication networks, such that communication services represent an elementary foundation of today’s globally connected economy. The telecommunication landscape has experienced dramatic transformations through the convergence of the Telecom and the Internet worlds. The previously closed telecommunication domain is currently transforming itself through the so-called NGN evolution into a highly dynamic multiservice infrastructure, supporting rich multimedia applications, as well as providing comprehensive support for various access technologies. The control layer of such NGNs is then of paramount importance, as representing the convergent mediator between access and services. The use and the optimization of the IP-Multimedia Subsystem (IMS) was researched and considered in this domain for many years now, such that today it represents the world-wide recognized control platform for fixed and mobile NGNs. Research on protocols and services for such NGN architectures, due to the convergence of technologies, applications and business models, as well as for enabling highly dynamic and short innovation cycles, is highly complex and requires early access to vendor independent - yet close to real life systems - validation environments, the so-called open technology test-beds. The present thesis describes the extensive research of the author over the last nine years in the field of open NGN test-beds. It focuses on the design, development and deployment of the Open Source IMS Core project, which represents since years the foundation of numerous NGN test-beds and countless NGN Research & Development projects in the academia as well as the industry domain around the globe. A major emphasis is given for ensuring flexibility, performance, reference functionality and inter-operability, as well as satisfying elementary design principles of such test-bed toolkits. The study also describes and evaluates the use of Open Source principles, highlighting the advantages of using it in regard to the creation, impact and sustainability of a global OpenIMSCore research community. Moreover, the work documents that the essential design principles and methodology employed can be reused in a generic way to create test-bed toolkits in other technology domains. This is shown by introducing the OpenEPC project, which provides for seamless integration of different mobile broadband technologies
    corecore