A hybrid decision approach for the association problem in heterogeneous networks

The area of networking games has had a growing impact on wireless networks. This reflects the recognition in the important scaling advantages that the service providers can benefit from by increasing the autonomy of mobiles in decision making. This may however result in inefficiencies that are inherent to equilibria in non-cooperative games. Due to the concern for efficiency, centralized protocols keep being considered and compared to decentralized ones. From the point of view of the network architecture, this implies the co-existence of network-centric and terminal centric radio resource management schemes. Instead of taking part within the debate among the supporters of each solution, we propose in this paper hybrid schemes where the wireless users are assisted in their decisions by the network that broadcasts aggregated load information. We derive the utilities related to the Quality of Service (QoS) perceived by the users and develop a Bayesian framework to obtain the equilibria. Numerical results illustrate the advantages of using our hybrid game framework in an association problem in a network composed of HSDPA and 3G LTE systems.Comment: 5 pages, 4 figures, IEEE Infocom, San Diego, USA, March 2010

Prise de décision de handover vertical pour la gestion de mobilité dans les réseaux hétérogènes sans fil

L évolution des technologies réseaux sans fil, des terminaux mobiles ainsi que des contenus et des services créent des environnements hétérogènes de plus en plus complexes. Dans ce contexte, un compromis entre la mobilité, la transparence et la performance apparaît. Des utilisateurs mobiles, ayant différents profils et préférences, voudraient être toujours connectés au meilleur réseau à tout moment, sans avoir à se soucier des différentes transitions entre réseaux hétérogènes. Face à cette complexité, il parait nécessaire de proposer de nouvelles approches afin de rendre ces systèmes plus autonomes et de rendre les décisions de handover vertical plus efficaces. Cette thèse se concentre sur la gestion de mobilité verticale, plus précisément sur la prise de décision de handover vertical dans un environnement de réseaux hétérogènes sans fil. Après l identification des différents paramètres de prise de décision et l analyse de l état de l art relié à la gestion de la mobilité verticale, nous avons proposé un système de réputation qui permet de réduire les délais de prise de décision. La réputation d un réseau est introduite comme une nouvelle métrique de prise de décision qui peut être recueillie à partir des expériences précédentes des utilisateurs sur ce réseau. Nous montrons que la réputation est une métrique efficace qui permet l anticipation du handover et accélère la prise de décision. Bien que l objectif principal soit de garantir la meilleure qualité de service et l utilisation optimale des ressources radios, les aspects économiques doivent également être considérés, y compris la minimisation des coûts pour les utilisateurs et la maximisation des revenus pour les fournisseurs de services ou les opérateurs. Nous proposons alors, dans la deuxième partie de la thèse, un mécanisme de prise de décision basé sur la théorie des jeux. Ce dernier permet la maximisation des utilités des réseaux et des utilisateurs. Dans cette solution, chaque réseau disponible joue un jeu de Stackelberg avec un ensemble d utilisateurs, tandis que les utilisateurs jouent un jeu de Nash entre eux pour partager les ressources radios limitées. Un point d équilibre de Nash, qui maximise l utilité de l utilisateur et les revenus des fournisseurs de services, est trouvé et utilisé pour le contrôle d admission et la prise de décision de handover vertical. Dans la troisième partie de cette thèse, nous proposons et discutons deux différentes solutions architecturales sur lesquelles nos mécanismes de prise de décision proposés peuvent être intégrés. La première architecture proposée est basée sur la norme IEEE 802.21 à laquelle nous proposons certaines extensions. La seconde architecture proposée est basée sur un niveau de contrôle composé de deux couches de virtualisation. La virtualisation est assurée via des agents capables de faire un raisonnement et de prendre des décisions pour le compte d entités physiques qu ils représentent au sein du système. Cette architecture permet une plus grande flexibilitéMobility management over heterogeneous wireless networks is becoming a major interest area as new technologies and services continue to proliferate within the wireless networking market. In this context, seamless mobility is considered to be crucial for ubiquitous computing. Service providers aim to increase the revenue and to improve users satisfaction. However there are still many technical and architectural challenges to overcome before achieving the required interoperability and coexistence of heterogeneous wireless access networks. Indeed, the context of wireless networks is offering multiple and heterogeneous technologies (e.g. 2G to 4G, WiFi, Wimax, TETRA,...). On the one hand, this rich environment allows users to take profit from different capacities and coverage characteristics. Indeed, this diversity can provide users with high flexibility and allow them to seamlessly connect at any time and any where to the access technology that best fits their requirements. Additionally, cooperation between these different technologies can provide higher efficiency in the usage of the scarce wireless resources offering more economic systems for network providers. On the other hand, the heterogeneity of technologies and architectures and the multiplication of networks and service providers creates a complex environment where cooperation becomes challenging at different levels including and not limited to mobility management, radio resource provisioning, Quality of Service and security guarantees. This thesis is focusing on mobility management and mainly on decision making for Vertical handover within heterogeneous wireless network environments. After the analysis of the related state of the art, we first propose a reputation based approach that allows fast vertical handover decision making. A decision making scheme is then built on that approach. Network s reputation, is a new metric that can be gathered from previous users experiences in the networks. We show that it is an efficient construct to speed up the vertical handover decision making thanks to anticipation functionalities. While the main objective remains guaranteeing the best Quality of Service and optimal radio resource utilization, economical aspects have also to be considered including cost minimization for users and revenue maximization for network providers. For this aim, we propose, in the second part of the thesis, a game theoretic based scheme that allows maximizing benefits for both networks and users. In this solution, each available network plays a Stackelberg game with a finite set of users, while users are playing a Nash game among themselves to share the limited radio resources. A Nash equilibrium point, that maximizes the user s utility and the service provider revenue, is found and used for admission control and vertical handover decision making. The analyses of the optimal bandwidth/prices and the revenue at the equilibrium point show that there are some possible policies to use according to user s requirements in terms of QoS and to network capacities. For instance, we pointed out that networks having same capacities and different reputation values should charge users with different prices which makes reputation management very important to attract users and maximize networks revenue. In the third part of this thesis, we provide and discuss two different architectural and implementation solutions on which our proposed vertical handover decision mechanisms can be integrated. The first proposed architecture is a centralized one. It is based on the IEEE 802.21 standard to which some extensions are proposed. The second proposed architecture is distributed. It is based on an overlay control level composed of two virtualization layers able to make reasoning on behalf of physical entities within the system. This architecture allows higher flexibility especially for loosely coupled interconnected networksEVRY-INT (912282302) / SudocSudocFranceF

LTE Optimization and Resource Management in Wireless Heterogeneous Networks

Mobile communication technology is evolving with a great pace. The development of the Long Term Evolution (LTE) mobile system by 3GPP is one of the milestones in this direction. This work highlights a few areas in the LTE radio access network where the proposed innovative mechanisms can substantially improve overall LTE system performance. In order to further extend the capacity of LTE networks, an integration with the non-3GPP networks (e.g., WLAN, WiMAX etc.) is also proposed in this work. Moreover, it is discussed how bandwidth resources should be managed in such heterogeneous networks. The work has purposed a comprehensive system architecture as an overlay of the 3GPP defined SAE architecture, effective resource management mechanisms as well as a Linear Programming based analytical solution for the optimal network resource allocation problem. In addition, alternative computationally efficient heuristic based algorithms have also been designed to achieve near-optimal performance

A Multi-Objective Approach for a Multihoming Load Balancing Scheme in WHN

The telco operators face up to challenges related to the need of ensuring a quality of service to the user in a planning, maintenance and resource allocation in their complex networks. These challenges are directly related with the need to ensure an user’s service with a good level of quality in a highly dynamic environment in terms of changes in the radio access technologies, growth in the number of mobile users, technical requirements of the new services and applications, and the possibility to connect to different networks at the same time, among others. In this paper, we address the problem of the user’s service allocation into the different feasible networks in order to reduce the network overloading. We present a multihoming load balancing scheme that allows the re-allocation of services according to their QoS requirements and the availability of network resources. We propose a multi-objective optimization model of this problem together with an evolutionary algorithm to solve it. Through simulation in different scenarios, we show that our algorithm is efficient, sensitive, scalable and provides optimal solutions

Multimedia packet forwarding in 802.11 networks with access point diversity

The characteristics of the wireless communication channels are usually time-varying, where the quality of the received signal changes rapidly over time within a few packet transmissions. The time-variability of the wireless channel is due to noise, fading, interference and mobility. An important artifact of these effects is the bursty packet losses observed at the link layer, and multimedia applications such as voice over IP and video-on-demand require resiliency against packet losses. Channel diversity is a well-known technique to alleviate the effects of time- variable wireless channels. In this thesis, we aim to apply link-layer diversity for resilient multimedia transmissions in IEEE 802.11 wireless networks. IEEE 802.11 wireless local area networks (WLANs) have widespread deployment in enterprises, public areas and homes. In many cases, a mobile user has the option of connecting to one of several 802.11 access point (APs). Unlike the standard operation where a mobile user is connected to a single AP for the duration of a session, we consider the case where a user is connected to all available APs in the vicinity. This type of operation requires a new multi-access control (MAC) protocol, where the user has to decide to which AP the packet is forwarded. The selection of the AP for each packet is performed in our proposed MAC protocol based on the most recent channel observation and the collected long-term statistics of packet loss and burstiness, where the aim is to maximize the probability of successful transmission of each packet. Our analysis of the long-term channel statistics such as burst length and packet error rate also show that these parameters depend on the user load, channel coherence time and the number of users in the network. The proposed MAC protocol is analyzed using Qualnet network simulator, and it is shown that our proposed protocol can improve the efficiency of the system approximately by up to %25 over the standard 802.11 protocol where each user is associated with the AP that has the maximum received signal strength

Network Selection and Resource Allocation Games for Wireless Access Networks

Wireless access networks are often characterized by the interaction of different end users, communication technologies, and network operators. This paper analyzes the dynamics among these "actors" by focusing on the processes of wireless network selection, where end users may choose among multiple available access networks to get connectivity, and resource allocation, where network operators may set their radio resources to provide connectivity. The interaction among end users is modeled as a non-cooperative congestion game where players (end users) selfishly select the access network that minimizes their perceived selection cost. A method based on mathematical programming is proposed to find Nash equilibria and characterize their optimality under three cost functions, which are representative of different technological scenarios. System level simulations are then used to evaluate the actual throughput and fairness of the equilibrium points. The interaction among end users and network operators is then assessed through a two-stage multi-leader/multi-follower game, where network operators (leaders) play in the first stage by properly setting the radio resources to maximize their users, and end users (followers) play in the second stage the aforementioned network selection game. The existence of exact and approximated subgame perfect Nash equilibria of the two-stage game is thoroughly assessed and numerical results are provided on the "quality" of such equilibria

Joint Access Point Selection and Power Allocation for Uplink Wireless Networks

We consider the distributed uplink resource allocation problem in a multi-carrier wireless network with multiple access points (APs). Each mobile user can optimize its own transmission rate by selecting a suitable AP and by controlling its transmit power. Our objective is to devise suitable algorithms by which mobile users can jointly perform these tasks in a distributed manner. Our approach relies on a game theoretic formulation of the joint power control and AP selection problem. In the proposed game, each user is a player with an associated strategy containing a discrete variable (the AP selection decision) and a continuous vector (the power allocation among multiple channels). We provide characterizations of the Nash Equilibrium of the proposed game, and present a set of novel algorithms that allow the users to efficiently optimize their rates. Finally, we study the properties of the proposed algorithms as well as their performance via extensive simulations.Comment: Revised and Resubmitted to IEEE Transactions on Signal Processin

Recent Advances in Wireless Communications and Networks

This book focuses on the current hottest issues from the lowest layers to the upper layers of wireless communication networks and provides "real-time" research progress on these issues. The authors have made every effort to systematically organize the information on these topics to make it easily accessible to readers of any level. This book also maintains the balance between current research results and their theoretical support. In this book, a variety of novel techniques in wireless communications and networks are investigated. The authors attempt to present these topics in detail. Insightful and reader-friendly descriptions are presented to nourish readers of any level, from practicing and knowledgeable communication engineers to beginning or professional researchers. All interested readers can easily find noteworthy materials in much greater detail than in previous publications and in the references cited in these chapters

Gestion de la mobilité pour l'internet du futur centré autour de l'information

L'Internet d'aujourd'hui a traversé série de changements évolutionnaires dans les quarante ou cinquante dernières années. Il a été conçu pour un réseau avec des nœuds fixes. Au début, le modèle de communication de l'Internet a été basé sur le réseau téléphonique (considéré comme 1er Génération Internet). Plus tard, il a été mis à jour comme un modèle client-serveur où la communication des systèmes d'échanger des données sur des liaisons dédiées. Cette 2ème génération Internet, au cours des années, a été contestée par de nombreux problèmes tels que la congestion du réseau, panne de chemin, les attaques DOS, gestion de la mobilité pour les réseaux sans fil, etc. Les utilisateurs d'Internet recherchent toujours des informations, indépendamment de la localisation (nœud ou serveur) où il se trouve ou stockées. Cette approche est la base d'une architecture où l'information est considérée comme l'unité primaire. Ces réseaux, en général, sont appelés en tant que Network of Information (NetInf), où l'information prend une position centrée remplaçant l'approche centrée sur nœud comme dans l'Internet aujourd'hui. Les problèmes rencontrés par l'Internet aujourd hui, mentionné ci-dessus, peuvent être traitées avec une approche unificatrice en mettant l'information au centre de l'architecture du réseau. À l'échelle mondiale, cette conception de l'architecture réseau est nommée Future Information Centric Internet . En parallèle, l'utilisation de l'Internet mobile a été augmentée durant la dernière décennie. Il a été environ 1,2 milliard abonnements de mobile broad band pour 2,4 milliards d utilisateurs d'Internet en 2011. En raison d augmentation de l'efficacité spectrale et ubiquitaire disponibilité de la connectivité cellulaire, la mobilité et la connectivité transparente est désormais considérée comme des produits de base la vie quotidienne. Néanmoins, en cas d'Internet, les solutions de mobilité basées sur IP ne peuvent pas rattraper son retard dans la performance avec l'évolution rapide des réseaux cellulaires. Par conséquent, l'un des principaux objectifs pour l'internet du futur est de concevoir des systèmes de gestion de mobilité qui permettent de surmonter les problèmes dans les réseaux sans fil tels que handover et la gestion de la localisation, multihoming, sécurité, etc. Dans cette thèse, nous avons proposé une solution de gestion de mobilité dans les réseaux sans fil dans le cadre du Information Centric Networking (ICN) en général et dans le contexte ne NetInf en particulier. NetInf est une architecture du Futur Internet basée sur le concept du ICN. Nous proposons un nœud mobile qui s appelle NetInf Mobile Node (NetInf MN). L'architecture de ce nœud est compatible avec l'architecture d'Internet basée sur TCP/TP. Cette conception de l'architecture travaille en collaboration avec Central Control Unit (CCU) pour améliorer les performances en cas de handover dans les réseaux sans fil. La Virtual Node Layer (VNL) algorithme explique comment les différents modules de NetInf MN et des unités CCU travaillé ensemble. La modèle mathématique basé sur Théorie de Jeu et Renforcement Learning (CODIPAS-RL) montre comment handover et data relaying sont géré dans les réseaux sans fil. Les résultats des simulations montrent que le modèle proposé réalise à la fois de Nash et de Stackelberg équilibres alors que le CODIPAS-RL régime atteint un optimum global. Enfin, comme un exemple de cas d'utilisation de l'architecture NetInf, nous proposons le NetInf Email Service qui ne requiert pas des serveurs et ports dédiés contrairement au service e-mail existante. L'utilisation de clés asymétriques comme l'ID de l'utilisateur est la caractéristique unique proposée pour ce service. Le NetInf Email service architecture présenté, explique comment différents éléments architecturaux travail ensemble. Nous discuter des défis différents et des besoins relatifs à ce service. Le prototype développé pour NetInf sera utilisée pour la mise en œuvre de ce serviceThe contemporary Internet ecosystem today has gone through series of evolutionary changes during the last forty or fifty years. Though it was designed as a network with fixed nodes, it has scaled well enough with the development of new technologies both in fixed and wireless networks. Initially, the communication model of the Internet was based on the telephone network (and can be considered as the 1st Generation Internet). Later, its transition as a client-server model made it a network where communication systems exchange data over dedicated links. This 2nd Generation Internet, over the years, has been challenged by many problems and issues such as network congestion, path failure, DOS attacks, mobility issues for wireless networks, etc. The Internet users always look for some information, irrespectively where it is located or stored. This approach is the basic building block for a network architecture where information is considered as the premier entity. Such networks, in general, are termed as Information Centric Network (ICN), where information takes centric position superseding the node centric approach like in the current Internet. The problems faced by the current Internet architecture, mentioned above, can be handled with a unifying approach by putting the information at the centre of the network architecture. On a global scale, this network architecture design is termed as the Future Information Centric Internet. Similarly, Mobile Internet usage has increased overwhelmingly in the last decade. There has been an estimated 1.2 billion mobile broad-band subscriptions for 2.4 billion Internet users in 2011. Because of the increased spectrum efficiency and ubiquitous availability of cellular connectivity, the seamless mobility and connectivity is now considered as daily life commodity. However, in the case of the Internet, IP based mobility solutions cannot catch up in performance with the fast evolution of cellular networks. Therefore, one of the primary goals for the Future Internet is the design of mobility management schemes that overcome the issues in wireless networks such as handover and location management, multihoming, security, etc. In this thesis, we have proposed a mobility management solution in wireless networks in the context of ICN in general and in the context of Network of Information (NetInf) in particular. NetInf is ICN-based Future Internet architecture. We propose a NetInf Mobile Node (NetInf MN) architecture which is backward compatible with the current Internet architecture as well. This cross architecture design for mobility support works closely with Central Control Unit (CCU) (network entity) for improved performance in case of handover management in wireless networks. The Virtual Node Layer (VNL) algorithm explains how different modules of NetInf MN and CCU units work together. The game theoretical and Reinforcement Learning (CODIPAS-RL) scheme based mathematical model shows how handover management and data relaying in the wireless networks can increase the network coverage through cooperative diversity. Simulation results show that the proposed model achieves both Nash and Stackelberg equilibria where as the selected CODIPAS-RL scheme reaches global optimum. Finally, as a use case example of NetInf architecture, we propose the NetInf Email service that does not require dedicated servers or dedicated port unlike the current email service. The use of asymmetric keys as user's ID is the unique feature proposed for this service. The NetInf email service architecture framework presented, explains how different architectural components work together. We discuss different challenges and requirements related to this service. The prototype developed for the Network of Information will be used for the implementation of this serviceEVRY-INT (912282302) / SudocSudocFranceF