A survey of network coverage prediction mechanisms in 4G heterogeneous wireless networks.

Seamless connectivity in 4G wireless networks requires the development of intelligent proactive mechanisms for efficiently predicting vertical handovers. Random device mobility patterns further increase the complexity of the handover process. Geographical topologies such as indoor and outdoor environments also exert additional constraints on network coverage and device mobility. The ability of a device to acquire refined knowledge about surrounding network coverage can significantly affect the performance of vertical handover prediction and QoS management mechanisms. This paper presents a comprehensive survey of research work conducted in the area of 4G wireless network coverage prediction for the optimisation of vertical handovers. It discusses different coverage prediction approaches and analyses their ability to accurately predict network coverage

Handover in Mobile Wireless Communication Network - A Review

Mobility is the characteristics of mobile communication that makes it irresistible by all and sundry. The whole world is now engaging in wireless communication as it provides users\u27 ability to communicate on-the-go. This is achieved by transferring users from a radio network to another. This process is called handover. Handover occurs either by cell crossing or by deterioration in signal quality of the current channel. The continuation of an active call is a critical characteristic in cellular systems. Brief overview of handover, handover type, commonly used handover parameters, some methods employed in the literature and we present the convergent point for furtherance in the area of mobile wireless communication Handover

A comprehensive survey on radio resource management in 5G HetNets: current solutions, future trends and open issues

The 5G network technologies are intended to accommodate innovative services with a large influx of data traffic with lower energy consumption and increased quality of service and user quality of experience levels. In order to meet 5G expectations, heterogeneous networks (HetNets) have been introduced. They involve deployment of additional low power nodes within the coverage area of conventional high power nodes and their placement closer to user underlay HetNets. Due to the increased density of small-cell networks and radio access technologies, radio resource management (RRM) for potential 5G HetNets has emerged as a critical avenue. It plays a pivotal role in enhancing spectrum utilization, load balancing, and network energy efficiency. In this paper, we summarize the key challenges i.e., cross-tier interference, co-tier interference, and user association-resource-power allocation (UA-RA-PA) emerging in 5G HetNets and highlight their significance. In addition, we present a comprehensive survey of RRM schemes based on interference management (IM), UA-RA-PA and combined approaches (UA-RA-PA + IM). We introduce a taxonomy for individual (IM, UA-RA-PA) and combined approaches as a framework for systematically studying the existing schemes. These schemes are also qualitatively analyzed and compared to each other. Finally, challenges and opportunities for RRM in 5G are outlined, and design guidelines along with possible solutions for advanced mechanisms are presented

Gestion de contexte pour l'optimisation de l'accès et l'adaptation des services sur des environnements hétérogènes

Dans le domaine des TIC, les services de demain seront certainement basés sur des systèmes ubiquitaires, omniprésents et pervasifs. Ces systèmes devront prendre en considération différents paramètres provenant de l environnement de l utilisateur, c est à dire son contexte. Le contexte de l utilisateur peut être composé d informations statiques ou dynamiques, objectives ou subjectives, quantitatives ou qualitatives. Il peut inclure des données telles que la localisation géographique, les caractéristiques du terminal utilisé, la température ambiante, l humeur de l utilisateur. Afin d améliorer la QoS et la QoE, les services et les systèmes doivent être adaptés aux changements du contexte des utilisateurs. Le contexte doit donc être collecté et interprété et les règles d adaptation du système doivent être définies. Sur les systèmes étendus, riches, dynamiques et hétérogènes, tels que ceux considéré dans le cadre de cette thèse, ces opérations doivent être automatisées. Vu la quantité et la complexité des données contextuelles à considérer, l utilisation de la sémantique dans la gestion de contexte peut faciliter cette automatisation et ouvrir la porte au raisonnement et à l adaptation automatiques. Aujourd hui, peu de solutions viables existent pour cette problématique. Nous proposons alors d utiliser et d adapter des mécanismes et technologies provenant du web sémantique pour décrire et manipuler les informations de contexte. Dans un premier temps, nous avons proposé une méthodologie de conception qui nous permit de proposer Ubiquity-Ont : une ontologie générique au domaine des TIC, flexible et extensible. Les données de contexte ont alors été décrites sous forme de concepts et d instances, reliés par des relations sémantiques. Nous avons ensuite proposé une architecture overlay, composée de deux niveaux de vitalisation et permettant d intégrer un gestionnaire de contexte, basé sur la sémantique, sur des environnements réseaux et services. Cette solution overlay permet de (a) masquer l hétérogénéité des composants du système et (b) d augmenter virtuellement les entités du système existant par les capacités nécessaires à la manipulation et au raisonnement sur les données sémantiques du contexte. Nos propositions ont étés implémentées et testées sur une plateforme réelle et appliquées à deux cas d études : Gestion de la mobilité sur des environnements de réseaux d accès hétérogènes et Optimisation de la consommation d énergie dans les terminaux mobilesFuture Information and Telecommunication Systems are expected to be pervasive and ubiquitous solutions, able to consider users context and to automatically adapt to their environments. Traditional configuration and management tools are not adapted. The richness, the heterogeneity and the complexity of the upcoming systems require automated solutions able to gather contextual information, to reason on them and to make the appropriate adaptation decisions. The representation and the sharing of contextual information is a key issue. In this thesis, we proposed and used a methodology to conceive Ubiquity-Ont , a generic ontology dedicated to Information and Telecommunication Systems. Contextual information are the described through semantic concepts, instances and relations. We then proposed an overlay architecture, composed of two virtualization layers that can integrate a semantic context management framework over existing networking environments. This architecture is able (a) to hide any heterogeneity among the system components and (b) to augment the different entities with additional capacities for context gathering, reasoning and sharing operations. The proposed solutions were then implemented and tested in Lab for two applications. The fisrt is related to mobility management over heterogeneous Wireless Networks and the second aims to power optimization on mobile terminals. These two case studies helped in proving and enhancing the proposed solutionsEVRY-INT (912282302) / SudocSudocFranceF