16 research outputs found

    Minimalist Self-Organization in Wireless Networks

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    Many fields of human endeavour, such as biology and the theory of complex systems, are now embracing the concept of self-organization based on local actions leading to a desirable global emergent behavior. While many examples, both natural and artificial, can be found of such self-organized systems, the relationship between the local rules and the global behavior remains elusive and no systematic procedure is known to engineer a specific global result. Given the increasing pervasiveness of wireless networks of all sorts, including ad hoc networks competing within narrow unlicensed bands and wireless sensor networks, self-organization could constitute the next defining paradigm in wireless communications. It can be shown that a set of heuristic principles can be leveraged to engineer a self-organized connection-oriented wireless network with minimal complexity. Such a system requires no centralization of information, yet achieves a nearly optimal global state with only a modest amount of local signaling. It will naturally and jointly balance the many parameters related to radio resource management, exhibiting great adaptability, fault tolerance and scalability

    Radio Communications

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    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

    Auto-tuning of RRM parameters in UMTS networks. Feasibility study.

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    Due to the intrinsic characteristics of WCDMA and the great number of services offered by UMTS, its radio channel is much more dynamic compared with GERAN systems. The traffic fluctuations and users mobility can cause the impairment of the network performance and of the quality of service (QoS) in certain cells. In the worst case a significant degradation of the QoS may be observed and as a result the operator defined targets are not met. Nowadays UMTS operators have fixed, and usually uniform, settings for their network parameters. This static configuration is not able to adapt automatically to the changes that occur in the network. A fixed parameter setting then gives a non optimal solution for the network optimization process and thus the utilization of the radio interface is not maximized. The goal of the automated tuning is to adjust dynamically these parameters in a continuous way without human intervention, which is only required in definition of the reference QoS. The current PFC aims at validating the feasibility of automated optimization of certain UMTS RRM parameters. The main tasks to be developed by the students are: - Simulator developement (Matlab programmed). A basic static Montecarlo simulator is available as a reference. - Study of UMTS handover algorithm and study of potential parameters to be automatically tuned. - Proposal of algorithm to tune the previously selected parameters, and evaluation of achieved gains. - Study of UMTS CAC algorithm and study of potential parameters to be automatically tuned. Development of first and basic ideas to propose tuning algorithm.The present PFC is located inside the framework of the UMTS networks, and more specifically in the development of new Radio Resource Management (RRM) algorithms capable to maximize the capacity and the performance of the network. In this sense a powerful simulation tool capable to analyze in depth the behavior of the UMTS network under different simulation scenarios has been developed. It has been focused in the study of the main algorithms that manage the allocation of radio resources in UMTS networks: Power Control (PC), Admission Control (AC) and Soft/Softer Handover (SHO). The problem observed in classical SHO strategies is the rigidity of the mechanism, which cannot adapt to variations in the traffic patterns. The improvements on SHO procedures are based on dynamic automated tuning of SHO parameters. A three blocks based functional architecture is described to adapt parameters to service mix dynamics and overcome capacity problems. Several tests have been done over different traffic situations in order to demonstrate the feasibility of the Auto-Tuning System (ATS). The results obtained show a considerable increment in the network capacity. In this sense ATS is considered as an effective pre-congestion-control strategy. Referring now to AC strategies, it is necessary to underline that three new AC algorithms have been implemented: Dynamic AC, Complete Partitioning AC (CP-AC) and Complete Sharing AC (CS-AC) strategies have been developed with the same goal, enhance the capacity of the network. Dynamic AC was proposed to provide flexibility to the current AC algorithm. This strategy is based on the ATS philosophy where a dynamic AC threshold is fixed to the optimum threshold in real time according to the current service mix. On the other hand, CS-AC and CP-AC are complex strategies based on static algorithms where fixed thresholds or load margins were applied in order to note their advantages and drawbacks depending on the users distribution, uniform or mostly close to the cell edge. As a result of this project a scientific publication inside the context of COST european projects has been carried out. In special, is about the COST 2100 ”Pervasive Mobile & Ambient Wireless Communications” and the title of the publication is ”Automatic Tuning of Soft Handover Parameters in UMTS Networks”. The paper was presented in the meeting number 3, held in Duisburg (Germany) between 10th and 12th of September 2007

    Final report on the evaluation of RRM/CRRM algorithms

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    Deliverable public del projecte EVERESTThis deliverable provides a definition and a complete evaluation of the RRM/CRRM algorithms selected in D11 and D15, and evolved and refined on an iterative process. The evaluation will be carried out by means of simulations using the simulators provided at D07, and D14.Preprin

    Multicast resource management for next generation mobile communication systems

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    EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Quality of service and mobility management in IP-based radio access networks

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    Master'sMASTER OF ENGINEERIN

    Proceedings of the Third Edition of the Annual Conference on Wireless On-demand Network Systems and Services (WONS 2006)

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    Ce fichier regroupe en un seul documents l'ensemble des articles accéptés pour la conférences WONS2006/http://citi.insa-lyon.fr/wons2006/index.htmlThis year, 56 papers were submitted. From the Open Call submissions we accepted 16 papers as full papers (up to 12 pages) and 8 papers as short papers (up to 6 pages). All the accepted papers will be presented orally in the Workshop sessions. More precisely, the selected papers have been organized in 7 session: Channel access and scheduling, Energy-aware Protocols, QoS in Mobile Ad-Hoc networks, Multihop Performance Issues, Wireless Internet, Applications and finally Security Issues. The papers (and authors) come from all parts of the world, confirming the international stature of this Workshop. The majority of the contributions are from Europe (France, Germany, Greece, Italy, Netherlands, Norway, Switzerland, UK). However, a significant number is from Australia, Brazil, Canada, Iran, Korea and USA. The proceedings also include two invited papers. We take this opportunity to thank all the authors who submitted their papers to WONS 2006. You helped make this event again a success

    Architecture d'un système de stations de base distribuées : macrodiversité, agents multiples et autoconfiguration

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    Le paradigme de station de bases distribuée (SDB) est étudié comme remplacement des structures plus rigides de stations de base cellulaire. Dans ce contexte, plusieurs SBD sont réparties afin d'offrir des zones de couverture radio se superposant et ainsi permettre à plusieurs SBD de relayer un même mobile pour lui offrir de la macrodiversité. De plus, les mobiles sont amenés à coopérer pour communiquer sur une même ressource radio afin d'augmenter l'efficacité spectrale par l'utilisation d'une plus grande diversité. L'étude du canal de coopération et macro diversité (de plusieurs mobiles à plusieurs SBD) est abordée afin d'offrir une base à la simulation de ceux-ci et ainsi étudier les interactions et la complexité qui découlent de l'utilisation de ces techniques. Ainsi, un système distribué, de la gestion des connexions (multiples) mobiles à SBD est proposé qui se base sur le concept d'agents multiples. Il est démontré que ceux-ci permet tent l'existence de schémas de connexion dynamiques qui s'auto-organisent. L'étude de l'interférence est ensuite abordée, et un deuxième système d'agents multiples est proposé pour la gestion de l'allocation des canaux. Enfin, la notion de coopération est abordée d'un point de vue systémique, c'est-à-dire en l'étudiant sur le réseau dans son ensemble. Il est montré que la coopération peut être efficace sous certaines conditions et qu'il est possible de gérer cette aptitude supplémentaire simplement avec le recourt d'agents multiples. En fin de compte, l'ensemble des systèmes d'agents proposés et de l'organisation du réseau de SBD permet effectivement d'obtenir des gains appréciables de diversité, d'efficacité spectrale, avec en prime tous les avantages découlant des propriétés distribuées des agents multiples: auto-configuration, adaptabilité, mise à l'échelle, etc
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