13 research outputs found

    Performance Comparison of MADM Algorithms for Network Selection in Heterogeneous Networks

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    Vertical handover is a need of present era of heterogeneous networks comprising different network technologies. Lot of quality of service (QoS) parameters, user�s preferences, network conditions and other parameters participate in selection of appropriate network among available networks. This multi- criteria nature of vertical handover verifiesapplicability of multiple attribute decision making (MADM) algorithms to be used for network selection in heterogeneous networks. In this work, six MADM algorithms SAW, MEW, TOPSIS, GRA, AHP and VIKOR have been implemented. Performance of these algorithms has beenanalyzed for handover latency,number of handovers and optimum network selection. It was concluded that VIKOR algorithm is able to provide compromised solution in the light of these parameters

    Improved handover decision algorithm using multiple criteria

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    The transfer of massive data between varied network positions links of network relies on data rate, as well as the traffic capacity of the network. Conventionally, a device that is mobile can be used to attain vertical handover functional by weighing in only an aspect, which refers to Received Signal Strength (RSS). The application of this particular criterion could lead to interruption in services, ineffective vertical handover, and a network load that is not balanced. Hence, this paper proposes an improvised vertical handover decision algorithm by integrating multi-criteria within a wireless network that is heterogeneous. The proposed algorithm comprised of three vertical handover decision algorithms, namely: mobile weight, network weight, and equal weight. Additionally, three technology interfaces were embedded in this study including Worldwide interoperability for Microwave Access (WiMAX), Wireless Local Area Network (WLAN), and Long-Term Evolution (LTE). As a result, the simulation outcomes demonstrated that the handover decision algorithm for network weight generated exceptional outputs, in comparison to mobile and equal weights, as well as the conventional network decision algorithm from the aspects of handover failure and handover number probabilities

    Mobile IPv4 based procedure for loose coupling architecture to optimize performance in heterogeneous wireless networks

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    One challenge of wireless networks integration is the ubiquitous wireless access abilities which provide the seamless handover for any moving communication device between the different types of technologies (3GPP and non-3GPP), such as GSM (Global System for Mobile Communication), Wireless Fidelity (Wi-Fi), Worldwide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunications System (UMTS) and Long Term Evolution (LTE). This challenge is important as mobile users (MUs) are becoming increasingly demanding for services regardless of the technological complexities associated with it. To fulfill these requirements for seamless Vertical Handover (VHO) two main interworking architectures have been proposed by European Telecommunication Standards Institute (ETSI) for integration between the different types of technologies; namely, loose and tight coupling. On the other hand, Media Independent Handover IEEE 802.21 (MIH) is a mechanism which has been proposed by IEEE group to provide seamless VHO between the aforementioned technologies by utilizing these interworking architectures to facilitate and complement its work. The paper presents the design and analysis of a Mobile IPv4 (MIPv4) based procedure for loose coupling architecture with MIH to optimize performance in heterogeneous wireless networks. Analytical results show that our procedure provides seamless VHO with minimal latency and low packet loss ratio

    I AM 4 VHO : new approach to improve seamless vertical handover in heterogeneous wireless networks

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    Two mechanisms have been proposed independently by IEEE and 3GPP; namely, Media Independent Handover (MIH) and Access Network Discovery and Selection Function (ANDSF), respectively. These mechanisms enable a seamless Vertical Handover (VHO) between the different types of technologies (3GPP and non-3GPP), such as GSM (Global System for Mobile Communication), Wireless Fidelity (Wi- Fi), Worldwide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunications System (UMTS) and Long Term Evolution (LTE). In this paper, we overview these mechanisms and show their components, benefits and drawbacks. Then we present our Imperative Alternative MIH for Vertical Handover (I AM 4 VHO) approach based on the approaches that have been studied in the literature with better performance (packet loss and latency), less connection failure (probability of reject sessions), less complexity and more exhaustive for enhancing VHO heterogeneous wireless networks environment

    Fuzzy logic-based intelligent scheme for enhancing QoS of vertical handover decision in vehicular ad-hoc networks

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    The design of next generation networks in various technologies under the “Anywhere, Anytime” paradigm offers seamless connectivity across different coverage. A conventional algorithm such as RSSThreshold algorithm, that only uses the received strength signal (RSS) as a metric, will decrease handover performance regarding handover latency, delay, packet loss, and handover failure probability. Moreover, the RSS-based algorithm is only suitable for horizontal handover decision to examine the quality of service (QoS) compared to the vertical handover decision in advanced technologies. In the next generation network, vertical handover can be started based on the user’s convenience or choice rather than connectivity reasons. This study proposes a vertical handover decision algorithm that uses a Fuzzy Logic (FL) algorithm, to increase QoS performance in heterogeneous vehicular ad-hoc networks (VANET). The study uses network simulator 2.29 (NS 2.29) along with the mobility traffic network and generator to implement simulation scenarios and topologies. This helps the simulation to achieve a realistic VANET mobility scenario. The required analysis on the performance of QoS in the vertical handover can thus be conducted. The proposed Fuzzy Logic algorithm shows improvement over the conventional algorithm (RSSThreshold) in the average percentage of handover QoS whereby it achieves 20%, 21% and 13% improvement on handover latency, delay, and packet loss respectively. This is achieved through triggering a process in layer two and three that enhances the handover performance

    Vertical Handoff Target Selection in a Heterogeneous Wireless Network Using Fuzzy ELECTRE

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    Global connectivity is on the verge of becoming a reality to provide high-speed, high-quality, and reliable communication channels for mobile devices at anytime, anywhere in the world. In a heterogeneous wireless environment, one of the key ingredients to provide efficient and ubiquitous computing with guaranteed quality and continuity of service is the design of intelligent handoff algorithms. Traditional single-metric handoff decision algorithms, such as Received Signal Strength (RSS), are not efficient and intelligent enough to minimize the number of unnecessary handoffs, decision delays, call-dropping and blocking probabilities. This research presents a novel approach for of a Multi Attribute Decision Making (MADM) model based on an integrated fuzzy approach for target network selection

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

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    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

    Context aware vertical handover decision making in heterogeneous wireless networks

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    International audienceProvisioning continuous services while moving through heterogeneous wireless networks is a main issue in the fourth generation wireless Networks. An efficient vertical handover decision making algorithm that takes into account services' requirements, considers users' preferences and guaranties seamless handover over heterogeneous technologies is required. In this paper, we propose an intelligent context-aware solution that considers both users and services requirements. It is based on advanced decision approaches like fuzzy logic and analytic hierarchy processe

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

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    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

    Improving initiation, decision and execution phases for vertical handover in heterogeneous wireless mobile networks

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    One of the challenging issues in Next Generation Wireless Systems (NGWS) is seamless Vertical Handover (VHO) during the mobility between different types of technologies (3GPP and non-3GPP) such as Global System for Mobile Communication (GSM), Wireless Fidelity (Wi-Fi), Worldwide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunications System (UMTS) and Long Term Evolution (LTE). Therefore, the telecommunication operators are required to develop aninteroperability strategy for these different types of existing networks to get the best connection anywhere, anytime without interruption of the ongoing sessions. In order to identify this problem accurately, the research study presented in this thesis provides four surveys about VHO approaches found in the literature. In these surveys, we classify the existing VHO approaches into categories based on the available VHO techniques for which we present their objectives and performances issues. After that, we propose an optimised VHO approach based on the VHO approaches that have been studied in the literature and take into consideration the research problems and conclusions which arearisen in our surveys. The proposed approach demonstrates better performance (packet loss, latency and signaling cost), less VHO connection failure (probability of minimising VHO reject sessions), less complexity and an enhanced VHO compared with that foundin the literature. It consists of a procedure which is implemented by an algorithm. The proposed procedure of loose coupling and Mobile Internet Protocol version 4 (MIPv4) provides early buffering for new data packets to minimise VHO packet loss and latency. Analysis and simulation of the proposed procedure show that the VHO packet loss and latency are significantly reduced compared with previous MIPv6 procedures found in the literature.The proposed algorithm is composed of two main parts: Handover Initiation and Optimum Radio Access Technologies (RATs) list of priority. The first part includes two main types of VHO and gives priority to imperative sessions over alternative sessions. IIIThis part is also responsible for deciding when and where to perform the handover by choosing the best RATs from the multiple ones available. Then, it passes them to the decision phase. This results in reducing the signaling cost and the inevitable degradation in Quality of Service (QoS) as a result of avoiding unnecessary handover processes. The second part defines RATs list of priority to minimise VHO connection failure. Analysis and simulation based performance evaluations then demonstrate that the proposed algorithm outperforms the traditional algorithms in terms of: (a) the probability of VHOconnection failure as a result of using the optimum RATs list of priority and (b) thesignaling cost and the inevitable degradation in QoS as a result of avoiding unnecessary handover processes
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