Academic literature on the topic 'Radiocommunications mobiles'
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Journal articles on the topic "Radiocommunications mobiles"
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-Israël, Renato. "Nouvelles radiocommunications mobiles : du GPRS à l'UMTS." Revue de l'Electricité et de l'Electronique -, no. 10 (2001): 28. http://dx.doi.org/10.3845/ree.2001.100.
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Zhuravleva, L. M., M. A. Nilov, V. L. Loshkarev, and V. V. Levshunov. "Evaluation of the Impact of Doppler Effect on Quality of HSR Radiocommunications." World of Transport and Transportation 18, no. 4 (January 5, 2021): 54–71. http://dx.doi.org/10.30932/1992-3252-2020-18-54-71.
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The article proposes a methodology for evaluating radio signal distortions caused by Doppler effect (DE; also, Doppler shift) under the conditions of highspeed train traffic (HSR, high-speed rail). The objective of the work is to develop criteria for assessing quality of radiocommunications with moving objects in HSR environment. For this, a technique is proposed for calculating the probability of an error arising from Doppler effect. A rationale for relevance of the topic is that radiocommunications are used on railways for controlling train traffic and ensuring safety and achieving required quality of radio signals is a major challenge. Quality assessment is especially important for organization of broadband communication channels with locomotive drivers using mobile networks. To solve this problem, a model for assessing quality of radiocommunication influenced by DE is considered. Distortions of signals in a radio channel due to DE are proposed to be estimated using the reduced dispersion of the total error, which consists of two components: dynamic and interference. Calculations of the total reduced signal error and the error probability for speeds above 100 km/h are described. Estimates of the effect of DE on a coherent receiver, in which errors may occur due to changes in duration of radio pulses, are suggested. Effectiveness of the receiver’s automatic frequency control (AFC) system is analysed as a means of challenging DE. For this, the concept of an instantaneous spectrum of parasitic frequency modulation due to DE was introduced and quality of radio communication was calculated using the reduced dispersion of the total error. The efficiency of using AFC has been proven after comparing the evaluations of reception quality with and without AFC in the form of the ratio of error probabilities. The features of the use of mobile communications on railways under the conditions of DE are formulated.
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Rozorinov, Heorhii, Oleksandr Hres, Volodymyr Rusyn, and Petro Shpatar. "ENVIRONMENT OF ELECTROMAGNETIC COMPATIBILITY OF RADIO-ELECTRONIC COMMUNICATION MEANS." Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska 10, no. 1 (March 30, 2020): 16–19. http://dx.doi.org/10.35784/iapgos.917.
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The conditions of ensuring electromagnetic compatibility of radio electronic means of mobile radio service have been analyzed. The stages of such analysis are outlined and a list of measures to be taken at each stage is given. The types of scenarios (paired, group) of interfering radio electronic means of mobile radio service are described. The technical specifications of the radiocommunication service equipment and antennas, which provide a statement of validation of the electromagnetic compatibility of the radiocommunication electronic means radiocommunication, are provided. An algorithm for determining the electromagnetic environment is proposed and recommendations for providing electromagnetic compatibility are offered.
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BIEŃKOWSKI, PAWEŁ, HALINA ANIOŁCZYK, JOLANTA KARPOWICZ, and JAROSŁAW KIELISZEK. "Exposure to the electromagnetic field in the work space during the use of transmitting devices of radiocommunication systems. The method of in situ measurements of the electromagnetic field – specific requirements." Podstawy i Metody Oceny Środowiska Pracy 33, no. 2(92) (May 25, 2017): 89–131. http://dx.doi.org/10.5604/01.3001.0010.0061.
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Labour law sets out the obligation to identify and evaluate electromagnetic hazards in the vicinity of radiocommunication equipment and installations emitting an electromagnetic field (EM-field). Following the regulation of the Ministry of Labour, which established provisions regarding health and safety regarding the EM-field, the "broadcasting tele- and radiocommunication systems” and “mobile phone base stations” have been mentioned among the typical sources of an EM-field (Regulation...., OJ 2016 item 950, amended by item 2284, Annex 1, items 4 and 5). Radiocommunication devices also include “mobile and cordless phones and wireless short distance devices (Regulation...., OJ 2016 item 950, amended by item 2284, Annex 1, item 3), which are devices in common use that do not require a radiocommunication permit, and so are not the subject of this article. Today, radiocommunication devices and systems are among the most common sources of the EM- -field, and while emissions the EM-field of protective zones exists in the vicinity of antennas and some other elements of such systems. The radiocommunication systems are usually operation-free, though they require adjusting and maintenance so workspaces may be identified in their vicinity. The conditions of the workers’ exposure to the EM-field while using radiocommunication systems must undergo periodic inspections made according to the recommended and validated methods, in order to identify electromagnetic hazards and to take appropriate protective measures (Regulation..., Journal of Laws 2011, item 166; Regulation..., OJ 2016 item 950, amended by item 2284). The methods of measuring the EM- -field to the extent necessary to meet these requirements are currently not standardised. Therefore, the aim of the work presented in this article was to develop a recommended method for measuring the parameters of the EM-field in situ in the workspace, while using radiocommunication devices. The recommended measurement method is based on a detailed investigation of the characteristics of exposure to the EM-field surrounding typical radiocommunication devices and systems operated in Poland in the vicinity of systems of antennas and transmitters of mobile phone base stations, broadcasting transmitters of radio and low power television and radio-television broadcasting centres. The work is based on the own results of measurements, as well as published literature and reports from inspection measurements of the EM-field. Based on the results of the study, it was shown that, besides the antennas, which create primary sources of EM-field (in some cases also transmitters and elements of the antenna feeder), in the workspace in their vicinity there are also secondary sources of EM-field: metal structures (ladders, handrails, fences, antennas supports, pipes and groundings) and receiving or inactivated transmitting antennas exposed to the EM-field from active transmitting antennas. In the article, the worked out method is shown for measuring the EM-field in the work space in the vicinity of stationary transmitting radio-communication devices and systems, requiring a radiocommunication permit. The most important sources of uncertainty concerning EM-field measurements near these devices were also discussed.
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Trinchero, S. "Exposure measuring techniques for wide band mobile radiocommunications." Radiation Protection Dosimetry 111, no. 4 (November 5, 2004): 429–33. http://dx.doi.org/10.1093/rpd/nch068.
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Ancans, G., E. Stankevicius, V. Bobrovs, and G. Ivanovs. "Estimation of Electromagnetic Compatibility Between DVB-T/DVB-T2 and 4G/5G in the 700 MHz Band for Co-Channel Case." Latvian Journal of Physics and Technical Sciences 57, no. 5 (October 1, 2020): 30–38. http://dx.doi.org/10.2478/lpts-2020-0025.
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AbstractThe 694–790 MHz band (700 MHz) known also as the second digital dividend was allocated to the mobile radiocommunication service on a primary basis in Region 1 and identified to International Mobile Telecommunications by the World Radiocommunication Conference 2012 (WRC-12). The designation of mobile service in Europe and other countries of Region 1 in 700 MHz band was obtained after the World Radiocommunication Conference 2015 (WRC-15). Administrations of Region 1 will be able to plan and use these frequencies for mobile networks, including IMT. The goal of this study is to estimate the electromagnetic compatibility of Digital Video Broadcasting – Terrestrial (DVB-T/DVB-T2) and LTE (Long Term Evolution) technology operating both in 700 MHz band. The study assumes frequency division duplex (FDD) channel arrangement of 703–733 MHz (for uplink) and of 758–788 MHz (for downlink).The model contains two parts: a DVB-T/DVB-T2 system and LTE mobile broadband network. Co-channel scenario is considered in this paper, and possible impact of DVB-T/DVB-T2 on LTE base stations (receivers) is also investigated. The Monte Carlo simulations within SEAMCAT software and the Minimum Coupling Loss (MCL) method are used for interference investigation. The coordination trigger field strength value predetermined by GE06 Agreement is also used in this study. The Monte Carlo method presents more relaxed electromagnetic compatibility scenario in comparison with the MCL method. For SEAMCAT simulations, ITU-R P.1546-5 radio propagation model is used.The obtained results present the required minimum separation distance between DVB-T/DVB-T2 and LTE networks in the 694–790 MHz in order to provide the necessary performance of LTE mobile network.
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Wnuk, Marian. "Adaptive Antenna Array Control Algorithm in Radiocommunication Systems." Algorithms 17, no. 2 (February 14, 2024): 81. http://dx.doi.org/10.3390/a17020081.
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An important element of modern telecommunications is wireless radio networks, which enable mobile subscribers to access wireless networks. The cell area is divided into independent sectors served by directional antennas. As the number of mobile network subscribers served by a single base station increases, the problem of interference related to the operation of the radio link increases. To minimize the disadvantages of omnidirectional antennas, base stations use antennas with directional radiation characteristics. This solution allows you to optimize the operating conditions of the mobile network in terms of reducing the impact of interference, better managing the frequency spectrum and improving the energy efficiency of the system. The work presents an adaptive antenna algorithm used in mobile telephony. The principle of operation of adaptive systems, the properties of their elements and the configurations in which they are used in practice are described. On this basis, an algorithm for controlling the radiation characteristics of adaptive antennas is presented. The control is carried out using a microprocessor system. The simulation model is described. An algorithm was developed based on the Mathcad mathematical program, and the simulation results of this algorithm, i.e., changes in radiation characteristics as a result of changing the mobile position of subscribers, were presented in the form of selected radiation characteristics charts.
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Ancans, G., V. Bobrovs, and G. Ivanovs. "Frequency Arrangement For 700 MHz Band." Latvian Journal of Physics and Technical Sciences 52, no. 1 (February 1, 2015): 52–67. http://dx.doi.org/10.1515/lpts-2015-0005.
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Abstract The 694-790 MHz (700 MHz) band was allocated by the 2012 World Radiocommunication Conference (WRC-12) in ITU Region 1 (Europe included), to the mobile service on a co-primary basis with other services to which this band was allocated on the primary basis and identified for the International Mobile Telecommunications (IMT). At the same time, the countries of Region 1 will be able also to continue using these frequencies for their broadcasting services if necessary. This allocation will be effective immediately after 2015 World Radiocommunication Conference (WRC-15). In order to make the best possible use of this frequency band for mobile service, a worldwide harmonized frequency arrangement is to be prepared to allow for large economies of scale and international roaming as well as utilizing the available spectrum in the best possible way, minimizing possible interference between services, facilitating deployment and cross-border coordination. The authors analyze different possible frequency arrangements and conclude on the frequency arrangement most suitable for Europe.
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Zentner, E., and J. Bartolić. "Intermodulation interference probability distribution in mobile radiocommunication systems." Electronics Letters 29, no. 3 (1993): 252. http://dx.doi.org/10.1049/el:19930173.
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Boldinov, Aleksey, and Andrey Privalov. "Mathematical Model for Control Channel of GSM-R Radiocommunication Standard." Proceedings of Petersburg Transport University 19, no. 4 (December 20, 2022): 743–51. http://dx.doi.org/10.20295/1815-588x-2022-4-743-751.
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Purpose: To develop a model for the evaluation and analysis of control logical channels (CC) performance quality of GSM-R radiocommunication standard. Methods: Performance process of shared control channel is presented in the form of a stochastic network with further obtaining equivalent function, average time and the function of distributing the time of information transfer in data transmission channel. Results: Mathematical model of shared CC performance process has been developed, corresponding to the algorithm of establishing connection of a mobile user with a network base station. The modeling results allow to conclude on the model adequacy and to assess the degree of various kind interference impact in a given area, including those created by violator’s jammers. The feasibility of reducing analysis time of the parameters of signals, transmitted from a mobile to base station, as well as the need to increase the noise immunity of signals for the control of entry into communication, received signal level and quality are shown. Practical significance: This model can be used to evaluate and analyze performance efficiency of control channels of GSM-R standard mobile radiocommunication real systems.
Dissertations / Theses on the topic "Radiocommunications mobiles"
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Simon, Viviane. "Turbo égalisation, application aux radiocommunications avec les mobiles." Brest, 1998. http://www.theses.fr/1998BRES2003.
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Cette these est consacree a l'etude d'un nouveau recepteur permettant de combattre efficacement l'interference entre les symboles engendree par les canaux selectifs en frequences, tels que les canaux de radiocommunications avec les mobiles. L'approche adoptee dans ce recepteur, nomme turbo egaliseur, est analogue a celle utilisee par c. Berrou et al pour decoder les codes correcteurs d'erreurs concatenes (turbo codes). Le turbo egaliseur associe, au travers d'un processus iteratif, un egaliseur, un entrelaceur et un decodeur de canal a sorties ponderees. A la premiere iteration, le dispositif d'egalisation consiste en un seul filtre transverse lineaire. Tandis qu'aux iterations suivantes, l'egaliseur est compose de deux filtres. Le premier filtre recoit le signal issu du demodulateur et permet de diminuer la puissance du bruit. Le second, quant-a-lui, est alimente par les valeurs moyennes des symboles calculees a partir de la sortie du decodeur de l'iteration precedente et vient annuler l'interference entre symboles en sortie du premier filtre. Les resultats obtenus ont montre que, sous certaines conditions, le turbo egaliseur est capable de supprimer toute l'interference entre symboles introduite par le canal de transmission sans remonter le niveau de bruit. Mots cles : interference entre symboles, egalisation adaptative, annulation d'interference, entrelacement, codage de canal, traitement iteratif, effet turbo, turbo egalisation.
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Kobbane, Abdellatif. "Evaluation des performances dans les réseaux cellulaires WCDMA avec des applications multimédia." Avignon, 2008. http://www.theses.fr/2008AVIG0159.
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Une évolution majeure des systèmes de troisième génération (3G) en comparaison avec ceux de deuxième génération (2G) est la possibilité d’offrir des services de haut débit. Ceci permet l’introduction des nouveaux services et notamment des services de données. Il est envisagé que les services de données formeront la plus grande partie du trafic écoulé dans les réseaux de 3G. Ces services vont coexister avec le service voix, déjà présent dans les systèmes de 2G. Par conséquent, des scénarios de trafic mixte doivent être considérés. L’existence des différents types de trafic augmente la complexité de la gestion des ressources radios. Le développement de systèmes de communication est actuellement limité par les contraintes sur la capacité de ces systèmes. En effet, l’augmentation du nombre d’accès simultanés génère de l’interférence qui dégrade la qualité de la communication. La définition de la capacité du réseau cellulaire WCDMA est liée au nombre d’appels ou bien au taux d’arrivée des appels qui garantit que la probabilité de rejet est inférieure à un seuil donné (capacité d’Erlang). Dans cette thèse nous calculons explicitement la capacité de liaison montante du système WCDMA avec deux types de trafic à savoir les appels en temps réel (RT) et les appels non temps réel appelés Best Effort (BE). Nous utilisons deux approches pour étudier les performances du système à savoir la méthode d’analyse spectrale et la méthode de perturbation singulière basée sur l’approximation. Nous comparons les deux approches puis nous validons notre résultat par le simulateur NS2. Nous étudions l’impact des pertes de paquets sur les performances du réseau cellulaire 3G en présence des applications multimédias. Par la suite, nous nous penchons sur l’étude des performances d’un système hétérogène composé de deux topologies à savoir le réseau UMTS et le réseau Ad-hocA major evolution of the third generation systems (3G) compared with those of second generation (2G), is the possibility to offer high and very high rates services. It allows the introduction of the new services and chiefly supports data transmissions. It’s expected that data services will form the biggest part of the traffic in 3G network. These services coexist with the voice service, which is already present in 2G systems. Therefore, schemes witch mixed traffic should be considered. The existence of the different types of traffic will lead then to an increased complexity and make management of the resources radios a real issue. The development of communication systems is limited currently by the constraints on the capacity of these systems. Indeed, the increase of the number of simultaneous access generates interference that deteriorates the quality of end to end the communication. The definition of the capacity of the WCDMA cellular network is bounded by the number of simultaneous calls or the rate of arrival that guarantees a reject probability lower than some given threshold (Erlang capacity ). In this thesis we explicitly calculate the capacity of uplink case the WCDMA systems in presence of two types of traffic. Namely real time calls (RT) and non real time calls (BE). We use two approaches to study the performances of this system to know indeed, we used the spectral analysis method and the singular perturbation method based on the approximation. We then compare the two approaches and validate our results using NS2 simulator. There after we bend a survey of the performances of a heterogeneous system, composed of two different topologies a UMTS subsystem and an Ad-hoc subsystem
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Rouil, Richard. "Gestion de la mobilité des terminaux dans les réseaux hétérogènes." Télécom Bretagne, 2009. http://www.theses.fr/2009TELB0100.
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Avec le succès des réseaux sans fil et l’intégration de plusieurs technologies de communication au sein d’un même terminal, les utilisateurs souhaitent que les fournisseurs d’accès offrent une connexion permanente lorsqu’ils se déplacent. Cependant, chaque technologie possède ses propres caractéristiques en termes de couverture ou de débit, et il est donc nécessaire de pouvoir passer d’un réseau à un autre ou de sélectionner la connexion la plus avantageuse. Nous commençons par une revue des technologies sans fil les plus couramment déployées telles que IEEE 802. 11, IEEE 802. 16, et Universal Mobile Telecommunications System (UMTS). Ensuite, nous présentons les solutions actuellement utilisées pour gérer la mobilité des nœuds et nous discutons de leurs limites par rapport aux délais de transferts de connexion entre les réseaux et à leurs supports pour la multi-domiciliation. En se basant sur l’architecture IEEE 802. 21 Media Independent Handover (MIH), nous analysons trois aspects majeurs de la mobilité : premièrement, nous étudions l’impact des déclencheurs de niveau 2 pour accélérer la détection de mouvement et nous fournissons des recommandations afin d’assurer la rapidité et la pertinence des déclencheurs. Deuxièmement, nous définissons plusieurs mécanismes d’optimisation comprenant un algorithme de balayage des canaux pour les réseaux IEEE 802. 16 qui prend en compte les contraintes de qualité de service des applications, ainsi que l’intégration des déclencheurs de niveau 2 dans les protocoles Mobile IPv6 pour réduire les temps de transferts de connexion et les paquets perdus. Enfin, nous analysons les performances des protocoles de transport pour échanger les messages de signalisation et faciliter les transferts de connexion, et nous proposons une solution optimisée qui combine Stream Control Transport Protocol (SCTP) et MIH. Pour supporter nos activités de recherche, nous avons développé des modèles de simulation pour ns-2 comprenant IEEE 802. 16, IEEE 802. 21, et plusieurs versions des protocoles Mobile IPv6With the success of wireless communications and the integration of multiple network interfaces in a single device, users are expecting network providers to offer ubiquitous connectivity while moving. However, each technology has its own characteristics in terms of network coverage or data rate, thus being able to move from one access network to another or selecting the most effective connection is necessary. After reviewing the capabilities of widely deployed wireless technologies such as IEEE 802. 11, IEEE 802. 16, and Universal Mobile Telecommunications System (UMTS), we present the current solutions used to handle node mobility and discuss their limitations in terms of handover latency or support for multihoming. Using the IEEE 802. 21 Media Independent Handover (MIH) as our framework, we focus on three major aspects of mobility: First, we study the impact of link triggers to enhance movement detection and provide guidelines in the trigger generation to ensure celerity and reliability. Then we provide various handover optimizations including a scanning algorithm for IEEE 802. 16 that maintains the applications’ Quality of Service (QoS) requirements and the integration of the link triggers with Mobile IPv6 protocols to reduce handover delays and packet loss. Finally, we look at the efficiency of several transport protocols to exchange information and facilitate handovers, and we propose an optimized solution combining Stream Control Transport Protocol (SCTP) and MIH. To support our research activities, we develop and validate simulation models of the standard protocols in the ns-2 simulator including IEEE 802. 16, IEEE 802. 21, and various flavors of Mobile IPv6 and use them to evaluate our proposed solutions
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Tabbane, Sami. "Méthodes d'accès et de diffusion dans les communications radio mobiles décentralisées à courte portée /." Paris : École nationale supérieure des télécommunications, 1992. http://catalogue.bnf.fr/ark:/12148/cb355861020.
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Samfat, Didier. "Architecture de sécurité pour réseaux mobiles /." Paris : Ecole nationale supérieure des télécommunications, 1996. http://catalogue.bnf.fr/ark:/12148/cb35810031x.
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Wu, Yi. "Entrelacement en fréquence et en temps avec codage pour la diffusion numérique vers les mobiles." Rennes 1, 1987. http://www.theses.fr/1987REN10006.
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Cette thèse propose une méthode de codage et de modulation associée à l'entrelacement en fréquence (éventuellement en fréquence et en temps) permettant de réduire, et même de supprimer l'aspect sélectif du canal tout en apportant l'indépendance necessaire au gain maximum offert par le codage. Outre l'étude de ce dispositif, d'autres méthodes telles que l'étalement de spectre, la diversité d'espace, avec cette dernière associée ou non au dispositif proposé, sont également considerées.
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Mederreg, Amal Wafa. "Méthodologie de test pour les services et protocoles des réseaux mobiles." Evry, Institut national des télécommunications, 2004. http://www.theses.fr/2004TELE0007.
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Les domaines des télécommunications et de l'informatique ont été marqués ces dernières années par des avancées majeures avec, en particulier, l'internet et les réseaux mobiles. Ces avancées ont donné naissance à l'idée d'une convergence entre l'internet et les réseaux mobiles, ceci dans le but de fournir plus de services et de fonctionnalités aux usagers. Pour arriver à cette convergence, il a été nécessaire de concevoir de nouveaux protocoles et équipements. Ces éléments (protocoles, équipement, services. . . ) peuvent être issus de concepteurs différents ce qui complique parfois leur bon fonctionnement. Il est important donc, avant qu'ils ne soient introduits dans les réseaux, de les faire passer par un ensemble d'étapes de production. Parmi ces étapes figure celle du test. Cette étape permet de détecter les erreurs pour les corriger et de garantir le bon fonctionnement de ces éléments. Dans la phase de test, le système passe par plusieurs étapes que l'on regroupe sous la dénomination de méthodologie de test. Cette dernière peut différer selon les types de tests que l'on veut effectuer. De plus, il est important d'automatiser ces étapes dans le but de réduire le temps et le coût de développement et surtout d'augmenter la fiabilité des produits proposés. Dans cette thèse, nous proposons deux méthodologies de test pour le domaine des télécommunications mobiles : une, pour le test de conformité des services et l'autre, pour le test d'interopérabilité. Ces deux méthodologies couvrent de manière automatique toutes les étapes de la production de tests (de la spécification du système à tester à leur exécution sur une plate-forme réelle)The domains of telecommunications and computing were marked these last years by major evolutions, in particular, with Internet and the mobile networks. These evolutions gave rise to the idea of a convergence between the Internet and the mobile networks, with the goal of providing more services and functionalities to the users. To reach this convergence, it was necessary ti think for new protocols and equpements. These elements (protocols, equipments, services. . . ) may be developed by different designers and this may complicate sometimes these elements correct work. Thus , before bringing them into the network, it is important to make them go through several steps of production. Among these steps appears the test step. The test step is provided in order to detect errors in the system, to correct them and to guarantee the correct operation of these elements. In the test phase, the system goes through several stages which we gather under the denomination of methodology of test. This methodology can be different according to the different test types we want to carry out. Moreover, it is important to automate these steps in order to reduce the time and the development cost an, mainly, to increase the reliability of the proposed products. In this thesis, we present two test methodologies for the mobile telecommunications domain : the services conformity test and the interoperability test. These two methodologies cover in an automatic way all the test production steps (from the systemunder test specification to the execution on a real platform)
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Haas, Ralf. "Application des transmissions à porteuses multiples aux communications radio mobiles /." Paris : Ecole nationale supérieure des télécommunications, 1996. http://catalogue.bnf.fr/ark:/12148/cb35810127z.
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Benayoune, Farès. "Gestion adaptative de contenus : influence de la mobilité sur la dynamique des réseaux." Evry, Institut national des télécommunications, 2007. http://www.theses.fr/2007TELE0013.
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Les environnements mobiles sans fil sont de plus en plus largement utilisés. Ils offrent de nombreuses opportunités que ne prennent pas toujours en compte les réseaux fixes existants. Leur objectif principal est de garantir un accès quasi normal à l’information quelle que soit la localisation de l’utilisateur. Toutefois, lorsque les utilisateurs se déplacent avec leurs machines (terminaux mobiles), il apparaît toute une série de problèmes jusqu’alors totalement ignorés en environnements classiques fixes. Ainsi, la compréhension de la mobilité des usagers devient cruciale pour les opérateurs et fournisseurs de services qui souhaitent optimiser leurs infrastructures et améliorer la QoS (Qualité de service). La mobilité des usagers pose un certain nombre de problèmes, comme par exemple l'organisation des points d’accès au réseau (APNs) en fonction de la densité des usagers, ou l'optimisation de l’accès aux contenus afin d’éviter la surcharge des serveurs et des liens. En effet, les systèmes de gestion de contenus existants ont été conçus pour les environnements filaires et s’adaptent très mal aux environnements sans fil ou mobiles. L’objectif de notre recherche est de proposer des mécanismes permettant d’améliorer la compréhension de la mobilité. Il est aussi d'appréhender son influence sur l’accès à l’information, afin d’optimiser l’évaluation des applications et de maîtriser la conception des nouveaux systèmes mobiles, telles les applications ubiquitaires et les nouvelles infrastructures réseaux. Nous avons caractérisé les comportements des utilisateurs mobiles en analysant des traces réelles via un outil de visualisation développé spécialement à cette fin. Notre étude focalise surtout sur les déplacements des utilisateurs entre les APNs du réseau. Nous nous sommes également fixé un objectif d’amélioration des modèles de mobilité théoriques existants, par la proposition de nouveaux éléments de modélisation, comme la fréquence de mobilité et la structure des parcours des usagers. Par ailleurs, nous proposons une solution pour la gestion adaptative de contenus. Elle intègre les fonctionnalités nécessaires pour optimiser l’accès en environnement mobile, en exploitant la synergie des groupes d’usagers présents dans chaque zone du réseau mobile. Une simulation de l’architecture nous a permis d’analyser l’influence de la mobilité des utilisateurs sur la circulation de contenus dans le réseau. Les résultats de la simulation montrent qu’il y a une corrélation entre, d'une part,la mobilité des contenus dans certaines régions et, d'autre part,le regroupement des usagers. Cela peut être pris en compte afin d’optimiser les systèmes d’accès existants et de réfléchir à de nouvelles organisations plus adéquatesThe wireless mobile environments become largely used and offer many opportunities which are not always taken into account by the existing wired systems. Their principal aim consists in guaranteeing access to information with regardless to users location. However, when the users move with their machines (mobile terminals), a set of problems appears, which are completely ignored in traditional wired environments. Thus understanding user behaviours has become crucial as a basis for developing and evaluating new applications, such as context-aware applications, and new wireless communication architectures, such as content access and replication. The mobility creates some new requirements on the architecture and on functions of the network. In particular, access points (APN) organisation according to the users density or improving data access in order to avoid servers and links overload. Indeed, the existing contents management systems were conceived for wired environments and adapt very badly to the wireless environments. The aim of our research is to propose mechanisms to improve comprehension of users mobility and its influence on data access in order to optimize the evaluation of the applications and to improve the design of the new mobile systems. We have characterized the behaviours of the mobile users by analyzing real traces via a visualization tool developed especially for these ends. Our study focuses especially on users displacements between APNs. Among our objectives is the improvement of the existing theoretical mobility models by the proposal of new elements of modelling like the frequency of mobility and the structure of users routes. In addition, we propose a solution for adaptive content management which integrates the functionalities to optimize data access in mobile environment, by exploiting the synergy of groups of users present in each zone of the network. A simulation of this global architecture has enabled us to analyze the influence of users mobility on content exchange within the network. The results of this simulation showed that there is a correlation between content mobility in certain areas and the regrouping of users. That can be taken into account in order to optimize the existing systems or thinking about new ones
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Reed, Sylvain. "Contribution à l'optimisation des performances des amplificateurs de puissance utilisés dans les terminaux portables pour les communications mobiles de futures générations." Nantes, 2005. http://www.theses.fr/2005NANT2009.
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Ce mémoire présente une nouvelle technique d'optimisation de performances des amplificateurs de puissance dédiés aux terminaux de radiocommunication mobiles de troisième génération. Le fonctionnement de ces composants doit être optimisé sur une grande dynamique de puissance de sortie. C'est pourquoi une nouvelle technique d'optimisation est développée : "amplificateur à polarisation dynamique adaptative". Elle consiste à injecter, au niveau du circuit de polarisation de base des transistors HBT constituant l'amplificateur de puissance, un signal qui est fonction de l'enveloppe du signal à amplifier et de la puissance de sortie. Ce signal peut être calculé dans la partie numérique du terminal mobile. Un nouveau banc de caractérisation a été conçu pour déterminer les signaux de polarisation optimaux. Un prototype a été réalisé en technologie hybride. Celui-ci permet de valider la technique développée. De plus, une conception monolithique a été développée pour démontrer son intégrabilitéThe work presented in this thesis deals with a new power amplifier optimization technique applied to the 3rd generation telecommunication system. It demonstrates that the power amplifier must be optimized over a wide output power range, which explains why a new optimization technique is developed : "Power Amplifier with Dynamic Adjust Biasing". This technique gives the HBT power amplifier base biasing circuit a signal which depends on the shape of the signal to be amplified and the output power. The biasing signal can be calculated by the digital part of the handset. Many measurements have been made on the power amplifier to characterize the power amplifier. A Proof-of-Concept was made to validate this optimization technique. Moreover, an integrated circuit has been developed to show that this technique can be integrated on a chip
Books on the topic "Radiocommunications mobiles"
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Jagoda, A. Les télécommunications mobiles: Le téléphone de poche européen. Paris: Eyrolles, 1991.
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Conférence internationale du service mobile par satellite. L' Ere des communications mobiles par satellites: Résumé des documents présentés à la quatrième Conférence internationale du service mobile par satellite, Ottawa, Canada, le 6 au 8 juin, 1995 : CICMS '95. Ottawa, Ont: Centre de recherches sur les communications, 1995.
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Desvignes, Yves Boutin. L' information routière. Paris: Presses Universitaires de France, 1996.
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Desvignes, Yves Boutin. L' information routière. Paris: Presses universitaires de France, 1996.
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Lauren, Collins. Mobile devices: Tools and technologies. Boca Raton, Florida: CRC Press/Taylor & Francis Group, 2015.
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International Workshop of teh EURO-NGI Network of Excellence (2nd 2005 Villa Vigoni, Italy). Wireless systems and network architectures in next generation internet: Second International Workshop of the EURO-NGI Network of Excellence, Villa Vigoni, Italy, July 13-15, 2005 ; revised selected papers. Berlin: Springer, 2006.
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Stüber, Gordon L. Principles of mobile communication. 2nd ed. Boston: Kluwer Academic, 2001.
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Stüber, Gordon L. Principles of mobile communication. 2nd ed. Boston: Kluwer Academic, 2001.
Find full textBook chapters on the topic "Radiocommunications mobiles"
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Jagoda, A., and M. de Villepin. "Private Radiocommunication." In Mobile Communications, 63–78. Wiesbaden: Vieweg+Teubner Verlag, 1993. http://dx.doi.org/10.1007/978-3-322-99269-7_5.
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Gould, Richard G. "The 1995 World Radiocommunication Conference (WRC-95) and its Effect on Mobile/Personal Satcoms." In Mobile and Personal Satellite Communications 2, 553–63. London: Springer London, 1996. http://dx.doi.org/10.1007/978-1-4471-1516-8_41.
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Sfez, R., J. C. Belfiore, K. Leeuwin, and A. Fihel. "Comparison of two modulation-coding schemes for low-rate digital land mobile radiocommunication." In EUROCODE '90, 350–63. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/3-540-54303-1_145.
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"LA RADIOCOMMUNICATION OU L’ANCÊTRE DES MOBILES." In Un monde sans fil, 9–34. Presses de l'Université du Québec, 2002. http://dx.doi.org/10.2307/j.ctv18pgrg1.7.
Full textConference papers on the topic "Radiocommunications mobiles"
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Stubbs, N. J. "The excellence of private mobile radio in public transportation." In IEE Colloquium on `Radiocommunications in Transportation'. IEE, 1995. http://dx.doi.org/10.1049/ic:19950678.
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Fruend, Juergen, Carsten Matysczok, Peter Ebbesmeyer, and Joerg Maciej. "AR-PDA: A Personal Digital Assistant for VR/AR Content." In ASME 2002 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/detc2002/cie-34393.
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This paper describes the development of an AR-based hard- and software system for a mobile digital assistant (AR-PDA). Target group for using this system is the large group of consumers. Here the AR-PDA uses AR technology to efficiently support users during their daily tasks. The technical realization of the system is based on 3rd generation video supported mobile phones. The user visualizes real objects with the AR-PDA. An integrated camera takes the pictures and the AR-PDA sends the video stream by mobile radiocommunication (e.g. UMTS) to the AR server. The server recognizes the objects by analyzing the image and establishes the relevant context-sensitive information, which is added to the video stream as multimedia elements (e.g. sound, video, text, images or virtual objects) and then sent back to the AR-PDA. The function validity is shown on the basis of close to practice application scenarios in the scope of household appliances.
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Oyama, Satoshi. "Status of ITS radiocommunications standards and their perspectives in Japan." In 2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC). IEEE, 2008. http://dx.doi.org/10.1109/pimrc.2008.4699968.
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Milkovic, D., and E. Zentner. "Quality measuring methods of coded speech in mobile radiocommunication systems." In 2005 18th International Conference on Applied Electromagnetics and Communications. IEEE, 2005. http://dx.doi.org/10.1109/icecom.2005.204927.
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Shishkin, A. V. "Digital information transfer in analog VHF radiotelephone channels of marine and air mobile radiocommunication services." In 2010 20th International Crimean Conference "Microwave & Telecommunication Technology" (CriMiCo 2010). IEEE, 2010. http://dx.doi.org/10.1109/crmico.2010.5632652.
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Хаджиева, Л. К., and Д. Х. Джабраилов. "5G TECHNOLOGY AS A NEW OFFER OF SMART EDUCATION." In «ОБРАЗОВАНИЕ БУДУЩЕГО» Материалы III Всероссийской научно-практической конференции с международным участием. Crossref, 2022. http://dx.doi.org/10.34708/gstou.2022.74.18.043.
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В данной статье рассматривается перспективы умного образования, которые стали возможны только с появлением технологии 5-го поколения. 5G - это не просто новый стандарт мобильной связи. Внедрение сетей 5-го поколения в долгосрочной перспективе может преобразовать наше восприятие мира и привести к трансформации общества. При этом изменится экономика сетей: средняя скорость передачи данных увеличится, а себестоимость доставки, напротив, уменьшится. После Всемирной конференции радиосвязи страны и организации по всему миру начали инвестировать в разработку и строительство технологии сети мобильной связи пятого поколения. Выпущен «План действий по информатизации образования», в который направлен на ускорение построения интеллектуальной системы обучения для колледжей и университетов, ориентированной на сеть следующего поколения, требующие «адаптации к развитию сетевых технологий 5G, отвечая новым требованиям интеллектуального обучения во всем мире. This article discusses the prospects for smart education, which became possible only with the advent of 5th generation technology. 5G is not just a new standard for mobile communications. The introduction of 5G networks in the long term can transform our perception of the world and lead to the transformation of society. At the same time, the economics of networks will change: the average data transfer rate will increase, while the cost of delivery, on the contrary, will decrease. After the World Radiocommunication Conference, countries and organizations around the world began to invest in the development and construction of fifth generation mobile network technology. The “Education Informatization Action Plan” has been released, which aims to accelerate theconstruction of a smart learning system for colleges and universities focused on the next generation network, requiring “adaptation to the development of 5G network technologies, meeting the new demands of smart learning around the world.