Enhanced Quality of Experience Based on Enriched Network Centric and Access Control Mechanisms

In the digital world service provisioning in user satisfying quality has become the goal of any content or network provider. Besides having satisfied and therefore, loyal users, the creation of sustainable revenue streams is the most important issue for network operators [1], [2], [3]. The motivation of this work is to enhance the quality of experience of users when they connect to the Internet, request application services as well as to maintain full service when these users are on the move in WLAN based access networks. In this context, the aspect of additional revenue creation for network operators is considered as well. The enhancements presented in this work are based on enriched network centric and access control mechanisms which will be achieved in three different areas of networks capabilities, namely the network performance, the network access and the network features themselves. In the area of network performance a novel authentication and authorisation method is introduced which overcomes the drawback of long authentication time in the handover procedure as required by the generic IEEE 802.1X process using the EAP-TLS method. The novel sequential authentication solution reduces the communication interruption time in a WLAN handover process of currently several hundred milliseconds to some milliseconds by combining the WPA2 PSK and the WPA2 EAP-TLS. In the area of usability a new user-friendly hotspot registration and login mechanisms is presented which significantly simplifies how users obtain WLAN hotspot login credentials and logon to a hotspot. This novel barcode initiated hotspot auto-login solution obtains user credentials through a simple SMS and performs an auto-login process that avoids the need to enter user name and password on the login page manually. In the area of network features a new system is proposed which overcomes the drawback that users are not aware of the quality in which a service can be provided prior to starting the service. This novel graceful denial of service solution informs the user about the expected application service quality before the application service is started

Pilotage dynamique de la qualité de service de bout en bout pour une session "user-centric"

Aujourd hui, le marché des services est devenu de plus en plus concurrentiel. Les exigences des clients pour des offres de service en adéquation avec leurs usages et leurs préférences conduisent les fournisseurs à proposer de nouveaux services qui répondent à ce nouveau besoin pour se démarquer des concurrents et attirer de nouveaux clients. Avec la convergence des réseaux et celle des services de nouvelle génération (NGN/NGS), de nouveaux services sont apparus. Les utilisateurs sont nomades et veulent utiliser leurs services de différentes manières n importe où, n importe quand et par n importe quel type de terminal, et cela avec une continuité de service et une qualité de service de bout en bout. Ainsi, fournir des services personnalisés aux clients dans un environnement hétérogène et mobile devient un challenge pour les opérateurs et les fournisseurs de service pour améliorer le retour sur investissement (ROI) et le délai de mise sur le marché (TTM). Nos réflexions à propos de la fourniture des services personnalisés selon les besoins fonctionnels et non-fonctionnels (QoS) des usagers, nous ont conduits à identifier les besoins du nouveau contexte NGN/NGS défini par l intersection de ces trois éléments user-centric, mobilité et QoS . Comment piloter dynamiquement la QoS de bout en bout pour une session unique user-centric ? Comment assurer le service Delivery dans un contexte de mobilité et d ubiquité? Ces nouveaux besoins, nous ont motivé à proposer des solutions à travers trois contributions principales qui prennent en considération la vision utilisateur et opérateur. Notre première contribution porte sur le modèle organisationnel. Nous proposons une nouvelle organisation avec un maximum de flexibilité, d adaptabilité et d autogestion, qui permet de piloter la QoS à chaque niveau de l architecture (équipement, réseau et service). Dans cette organisation nous avons défini des acteurs et le rôle que joue chacun d eux par rapport à la prise de décision au cours de la session de l utilisateur, et cela pour maintenir la QoS de bout en bout dans un environnement qui est totalement hétérogène et mobile.Notre deuxième contribution traite du composant de service autonomique. Avec la complexité de la personnalisation des services dans un contexte hétérogène et mobile et le besoin de satisfaire la QoS de bout en bout, les ressources services doivent être prises en compte au même titre que les ressources réseaux. Donc, un degré élevé d autosuffisance, d autogestion et d automatisation est demandé dans la ressource service (composant de service) pour améliorer le service delivery. Pour cela, nous proposons un composant de service autonomique ASC: Autonomic Service Component basé sur un agent de QoS intégré qui s autocontrôle et s autogère pour adapter dynamiquement ses ressources en réponse à un changement de situations au cours de la session de l utilisateur. Notre troisième proposition couvre le modèle protocolaire. La session de services personnalisés nécessite des interactions plus flexibles au niveau service pour avoir une session unique avec une continuité de service. Nous proposons un protocole de signalisation SIP+ qui permet la négociation de la QOS des services personnalisés dès la phase d initialisation de la session et de la renégociation de la QoS pendant l usage, pour maintenir le service avec la QoS requise à travers une session unique.De façon plus concrète, nous présentons nos expérimentations à travers un scenario et une plate-forme de démonstration qui nous permet de tester la faisabilité et la performance de nos contributions. Les apports et les perspectives de cette thèse sont consignés en conclusion.Nowadays, the services market has become increasingly competitive. Customer requirements for service offerings in line with their uses and preferences led providers to offer new services to meet this new need and to stand out from competitors and attract new customers. With the success of the network and service convergence (NGN / NGS), new services have emerged. A mobile user desires to access his services anywhere, anytime and on any type of terminal.Thus, providing customized services to clients while ensuring the service continuity and the end-to-end quality of service in a heterogeneous and mobile environment became a challenge for mobile operators and service providers to improve the return on investment (ROI) and time-to-market (TTM). Our thinking about the provision of customized services according to the functional and non-functional (QoS) needs of the users has led us to identify the needs of the new context NGN / NGS defined by the intersection of these three elements "user-centric, mobility and QoS". How to dynamically control the end-to-end QoS for a single "user-centric" session? How to ensure the "Service Delivery" in the context of mobility and ubiquity? These new needs have led us to propose solutions through three main contributions that take into account the user and the operator vision. Our first contribution concerns the organizational model. We have proposed a new organization with a maximum of flexibility, adaptability and self-management which allows the control of the QoS at each level of the architecture (equipment, network and service). In this organization, we have defined actors and the role of each one in relation to the decision-making process during the user session in order to maintain the end-to-end QoS in an environment that is totally heterogeneous and mobile. Our second contribution addresses the autonomic service component. With the complexity of services personalization in a heterogeneous and mobile context and the need to satisfy the end to end QoS, services and network resources must be taken into account. Therefore, a high degree of self-sufficiency, self-management and automation is required in the resource service to improve the service delivery. We have therefore proposed an autonomic service component based on an integrated QoS-agent which is self-controlled and self-managed to dynamically adapt its resources in response to changing situations during the user s session. Our third proposal covers the model protocol. The personalized services session requires more flexible interactions at the service level in order to obtain a single session with service continuity. We have proposed a signalling protocol SIP + that allows the negotiation of the QoS of personalized services at the session initialization phase and the renegotiation of the QoS during the utilization to maintain the service with the required QoS through a unique session. More concretely, we have presented our experiments through a scenario and demonstration platform that allows us to test the feasibility and the performance of our contributions. The contributions and perspectives of this thesis are stated in the conclusion.PARIS-Télécom ParisTech (751132302) / SudocSudocFranceF

Adaptive Communications for Next Generation Broadband Wireless Access Systems

Un dels aspectes claus en el disseny i gestió de les xarxes sense fils d'accés de banda ampla és l'ús eficient dels recursos radio. Des del punt de vista de l'operador, l'ample de banda és un bé escàs i preuat que s´ha d'explotar i gestionar de la forma més eficient possible tot garantint la qualitat del servei que es vol proporcionar. Per altra banda, des del punt de vista del usuari, la qualitat del servei ofert ha de ser comparable al de les xarxes fixes, requerint així un baix retard i una baixa pèrdua de paquets per cadascun dels fluxos de dades entre la xarxa i l'usuari. Durant els darrers anys s´han desenvolupat nombroses tècniques i algoritmes amb l'objectiu d'incrementar l'eficiència espectral. Entre aquestes tècniques destaca l'ús de múltiples antenes al transmissor i al receptor amb l'objectiu de transmetre diferents fluxos de dades simultaneament sense necessitat d'augmentar l'ample de banda. Per altra banda, la optimizació conjunta de la capa d'accés al medi i la capa física (fent ús de l'estat del canal per tal de gestionar de manera optima els recursos) també permet incrementar sensiblement l'eficiència espectral del sistema.L'objectiu d'aquesta tesi és l'estudi i desenvolupament de noves tècniques d'adaptació de l'enllaç i gestió dels recursos ràdio aplicades sobre sistemes d'accés ràdio de propera generació (Beyond 3G). Els estudis realitzats parteixen de la premissa que el transmisor coneix (parcialment) l'estat del canal i que la transmissió es realitza fent servir un esquema multiportadora amb múltiples antenes al transmisor i al receptor. En aquesta tesi es presenten dues línies d'investigació, la primera per casos d'una sola antenna a cada banda de l'enllaç, i la segona en cas de múltiples antenes. En el cas d'una sola antena al transmissor i al receptor, un nou esquema d'assignació de recursos ràdio i priorització dels paquets (scheduling) és proposat i analitzat integrant totes dues funcions sobre una mateixa entitat (cross-layer). L'esquema proposat té com a principal característica la seva baixa complexitat i que permet operar amb transmissions multimedia. Alhora, posteriors millores realitzades per l'autor sobre l'esquema proposat han permès també reduir els requeriments de senyalització i combinar de forma óptima usuaris d'alta i baixa mobilitat sobre el mateix accés ràdio, millorant encara més l'eficiència espectral del sistema. En cas d'enllaços amb múltiples antenes es proposa un nou esquema que combina la selecció del conjunt optim d'antenes transmissores amb la selecció de la codificació espai- (frequència-) temps. Finalment es donen una sèrie de recomanacions per tal de combinar totes dues línies d'investigació, així con un estat de l'art de les tècniques proposades per altres autors que combinen en part la gestió dels recursos ràdio i els esquemes de transmissió amb múltiples antenes.Uno de los aspectos claves en el diseño y gestión de las redes inalámbricas de banda ancha es el uso eficiente de los recursos radio. Desde el punto de vista del operador, el ancho de banda es un bien escaso y valioso que se debe explotar y gestionar de la forma más eficiente posible sin afectar a la calidad del servicio ofrecido. Por otro lado, desde el punto de vista del usuario, la calidad del servicio ha de ser comparable al ofrecido por las redes fijas, requiriendo así un bajo retardo y una baja tasa de perdida de paquetes para cada uno de los flujos de datos entre la red y el usuario. Durante los últimos años el número de técnicas y algoritmos que tratan de incrementar la eficiencia espectral en dichas redes es bastante amplio. Entre estas técnicas destaca el uso de múltiples antenas en el transmisor y en el receptor con el objetivo de poder transmitir simultáneamente diferentes flujos de datos sin necesidad de incrementar el ancho de banda. Por otro lado, la optimización conjunta de la capa de acceso al medio y la capa física (utilizando información de estado del canal para gestionar de manera óptima los recursos) también permite incrementar sensiblemente la eficiencia espectral del sistema.El objetivo de esta tesis es el estudio y desarrollo de nuevas técnicas de adaptación del enlace y la gestión de los recursos radio, y su posterior aplicación sobre los sistemas de acceso radio de próxima generación (Beyond 3G). Los estudios realizados parten de la premisa de que el transmisor conoce (parcialmente) el estado del canal a la vez que se considera que la transmisión se realiza sobre un sistema de transmisión multiportadora con múltiple antenas en el transmisor y el receptor. La tesis se centra sobre dos líneas de investigación, la primera para casos de una única antena en cada lado del enlace, y la segunda en caso de múltiples antenas en cada lado. Para el caso de una única antena en el transmisor y en el receptor, se ha desarrollado un nuevo esquema de asignación de los recursos radio así como de priorización de los paquetes de datos (scheduling) integrando ambas funciones sobre una misma entidad (cross-layer). El esquema propuesto tiene como principal característica su bajo coste computacional a la vez que se puede aplicar en caso de transmisiones multimedia. Posteriores mejoras realizadas por el autor sobre el esquema propuesto han permitido también reducir los requisitos de señalización así como combinar de forma óptima usuarios de alta y baja movilidad. Por otro lado, en caso de enlaces con múltiples antenas en transmisión y recepción, se presenta un nuevo esquema de adaptación en el cual se combina la selección de la(s) antena(s) transmisora(s) con la selección del esquema de codificación espacio-(frecuencia-) tiempo. Para finalizar, se dan una serie de recomendaciones con el objetivo de combinar ambas líneas de investigación, así como un estado del arte de las técnicas propuestas por otros autores que combinan en parte la gestión de los recursos radio y los esquemas de transmisión con múltiples antenas.In Broadband Wireless Access systems the efficient use of the resources is crucial from many points of views. From the operator point of view, the bandwidth is a scarce, valuable, and expensive resource which must be exploited in an efficient manner while the Quality of Service (QoS) provided to the users is guaranteed. On the other hand, a tight delay and link quality constraints are imposed on each data flow hence the user experiences the same quality as in fixed networks. During the last few years many techniques have been developed in order to increase the spectral efficiency and the throughput. Among them, the use of multiple antennas at the transmitter and the receiver (exploiting spatial multiplexing) with the joint optimization of the medium access control layer and the physical layer parameters.In this Ph.D. thesis, different adaptive techniques for B3G multicarrier wireless systems are developed and proposed focusing on the SS-MC-MA and the OFDM(A) (IEEE 802.16a/e/m standards) communication schemes. The research lines emphasize into the adaptation of the transmission having (Partial) knowledge of the Channel State Information for both; single antenna and multiple antenna links. For single antenna links, the implementation of a joint resource allocation and scheduling strategy by including adaptive modulation and coding is investigated. A low complexity resource allocation and scheduling algorithm is proposed with the objective to cope with real- and/or non-real- time requirements and constraints. A special attention is also devoted in reducing the required signalling. However, for multiple antenna links, the performance of a proposed adaptive transmit antenna selection scheme jointly with space-time block coding selection is investigated and compared with conventional structures. In this research line, mainly two optimizations criteria are proposed for spatial link adaptation, one based on the minimum error rate for fixed throughput, and the second focused on the maximisation of the rate for fixed error rate. Finally, some indications are given on how to include the spatial adaptation into the investigated and proposed resource allocation and scheduling process developed for single antenna transmission

Cyclic blackout mitigation and prevention

Severe and long-lasting power shortages plague many countries, resulting in cyclic blackouts affecting the life of millions of people. This research focuses on the design, development and evolution of a computer-controlled system for chronic cyclic blackouts mitigation based on the use of an agent-based distributed power management system integrating Supply Demand Matching (SDM) with the dynamic management of Heat, Ventilation, and Air Conditioning (HVAC) appliances. The principle is supported through interlocking different types of HVAC appliances within an adaptive cluster, the composition of which is dynamically updated according to the level of power secured from aggregating the surplus power from underutilised standby generation which is assumed to be changing throughout the day. The surplus power aggregation provides a dynamically changing flow, used to power a basic set of appliances and one HVAC per household. The proposed solution has two modes, cyclic blackout mitigation and prevention modes, selecting either one depends on the size of the power shortage. If the power shortage is severe, the system works in its cyclic blackout mitigation mode during the power OFF periods of a cyclic blackout. The system changes the composition of the HVAC cluster so that its demand added to the demand of basic household appliances matches the amount of secured supply. The system provides the best possible air conditioning/cooling service and distributes the usage right and duration of each type of HVAC appliance either equally among all houses or according to house temperature. However if the power shortage is limited and centred around the peak, the system works in its prevention mode, in such case, the system trades a minimum number of operational air conditioners (ACs) with air cooling counterparts in so doing reducing the overall demand. The solution assumes the use of a new breed of smart meters, suggested in this research, capable of dynamically rationing power provided to each household through a centrally specified power allocation for each family. This smart meter dynamically monitors each customer’s demand and ensures their allocation is never exceeded. The system implementation is evaluated utilising input power usage patterns collected through a field survey conducted in a residential quarter in Basra City, Iraq. The results of the mapping formed the foundation for a residential demand generator integrated in a custom platform (DDSM-IDEA) built as the development environment dedicated for implementing and evaluating the power management strategies. Simulation results show that the proposed solution provides an equitably distributed, comfortable quality of life level during cyclic blackout periods.Severe and long-lasting power shortages plague many countries, resulting in cyclic blackouts affecting the life of millions of people. This research focuses on the design, development and evolution of a computer-controlled system for chronic cyclic blackouts mitigation based on the use of an agent-based distributed power management system integrating Supply Demand Matching (SDM) with the dynamic management of Heat, Ventilation, and Air Conditioning (HVAC) appliances. The principle is supported through interlocking different types of HVAC appliances within an adaptive cluster, the composition of which is dynamically updated according to the level of power secured from aggregating the surplus power from underutilised standby generation which is assumed to be changing throughout the day. The surplus power aggregation provides a dynamically changing flow, used to power a basic set of appliances and one HVAC per household. The proposed solution has two modes, cyclic blackout mitigation and prevention modes, selecting either one depends on the size of the power shortage. If the power shortage is severe, the system works in its cyclic blackout mitigation mode during the power OFF periods of a cyclic blackout. The system changes the composition of the HVAC cluster so that its demand added to the demand of basic household appliances matches the amount of secured supply. The system provides the best possible air conditioning/cooling service and distributes the usage right and duration of each type of HVAC appliance either equally among all houses or according to house temperature. However if the power shortage is limited and centred around the peak, the system works in its prevention mode, in such case, the system trades a minimum number of operational air conditioners (ACs) with air cooling counterparts in so doing reducing the overall demand. The solution assumes the use of a new breed of smart meters, suggested in this research, capable of dynamically rationing power provided to each household through a centrally specified power allocation for each family. This smart meter dynamically monitors each customer’s demand and ensures their allocation is never exceeded. The system implementation is evaluated utilising input power usage patterns collected through a field survey conducted in a residential quarter in Basra City, Iraq. The results of the mapping formed the foundation for a residential demand generator integrated in a custom platform (DDSM-IDEA) built as the development environment dedicated for implementing and evaluating the power management strategies. Simulation results show that the proposed solution provides an equitably distributed, comfortable quality of life level during cyclic blackout periods

Radio Communications

In the last decades the restless evolution of information and communication technologies (ICT) brought to a deep transformation of our habits. The growth of the Internet and the advances in hardware and software implementations modified our way to communicate and to share information. In this book, an overview of the major issues faced today by researchers in the field of radio communications is given through 35 high quality chapters written by specialists working in universities and research centers all over the world. Various aspects will be deeply discussed: channel modeling, beamforming, multiple antennas, cooperative networks, opportunistic scheduling, advanced admission control, handover management, systems performance assessment, routing issues in mobility conditions, localization, web security. Advanced techniques for the radio resource management will be discussed both in single and multiple radio technologies; either in infrastructure, mesh or ad hoc networks