2,006 research outputs found

    Self organising cloud cells: a resource efficient network densification strategy

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    Network densification is envisioned as the key enabler for 2020 vision that requires cellular systems to grow in capacity by hundreds of times to cope with unprecedented traffic growth trends being witnessed since advent of broadband on the move. However, increased energy consumption and complex mobility management associated with network densifications remain as the two main challenges to be addressed before further network densification can be exploited on a wide scale. In the wake of these challenges, this paper proposes and evaluates a novel dense network deployment strategy for increasing the capacity of future cellular systems without sacrificing energy efficiency and compromising mobility performance. Our deployment architecture consists of smart small cells, called cloud nodes, which provide data coverage to individual users on a demand bases while taking into account the spatial and temporal dynamics of user mobility and traffic. The decision to activate the cloud nodes, such that certain performance objectives at system level are targeted, is carried out by the overlaying macrocell based on a fuzzy-logic framework. We also compare the proposed architecture with conventional macrocell only deployment and pure microcell-based dense deployment in terms of blocking probability, handover probability and energy efficiency and discuss and quantify the trade-offs therein

    An intelligent radio access network selection and optimisation system in heterogeneous communication environments

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    PhDThe overlapping of the different wireless network technologies creates heterogeneous communication environments. Future mobile communication system considers the technological and operational services of heterogeneous communication environments. Based on its packet switched core, the access to future mobile communication system will not be restricted to the mobile cellular networks but may be via other wireless or even wired technologies. Such universal access can enable service convergence, joint resource management, and adaptive quality of service. However, in order to realise the universal access, there are still many pending challenges to solve. One of them is the selection of the most appropriate radio access network. Previous work on the network selection has concentrated on serving the requesting user, but the existing users and the consumption of the network resources were not the main focus. Such network selection decision might only be able to benefit a limited number of users while the satisfaction levels of some users are compromised, and the network resources might be consumed in an ineffective way. Solutions are needed to handle the radio access network selection in a manner that both of the satisfaction levels of all users and the network resource consumption are considered. This thesis proposes an intelligent radio access network selection and optimisation system. The work in this thesis includes the proposal of an architecture for the radio access network selection and optimisation system and the creation of novel adaptive algorithms that are employed by the network selection system. The proposed algorithms solve the limitations of previous work and adaptively optimise network resource consumption and implement different policies to cope with different scenarios, network conditions, and aims of operators. Furthermore, this thesis also presents novel network resource availability evaluation models. The proposed models study the physical principles of the considered radio access network and avoid employing assumptions which are too stringent abstractions of real network scenarios. They enable the implementation of call level simulations for the comparison and evaluation of the performance of the network selection and optimisation algorithms

    Quality-Oriented Mobility Management for Multimedia Content Delivery to Mobile Users

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    The heterogeneous wireless networking environment determined by the latest developments in wireless access technologies promises a high level of communication resources for mobile computational devices. Although the communication resources provided, especially referring to bandwidth, enable multimedia streaming to mobile users, maintaining a high user perceived quality is still a challenging task. The main factors which affect quality in multimedia streaming over wireless networks are mainly the error-prone nature of the wireless channels and the user mobility. These factors determine a high level of dynamics of wireless communication resources, namely variations in throughput and packet loss as well as network availability and delays in delivering the data packets. Under these conditions maintaining a high level of quality, as perceived by the user, requires a quality oriented mobility management scheme. Consequently we propose the Smooth Adaptive Soft-Handover Algorithm, a novel quality oriented handover management scheme which unlike other similar solutions, smoothly transfer the data traffic from one network to another using multiple simultaneous connections. To estimate the capacity of each connection the novel Quality of Multimedia Streaming (QMS) metric is proposed. The QMS metric aims at offering maximum flexibility and efficiency allowing the applications to fine tune the behavior of the handover algorithm. The current simulation-based performance evaluation clearly shows the better performance of the proposed Smooth Adaptive Soft-Handover Algorithm as compared with other handover solutions. The evaluation was performed in various scenarios including multiple mobile hosts performing handover simultaneously, wireless networks with variable overlapping areas, and various network congestion levels

    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

    Network-driven handover in 5G

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    Currently, users’ expectations regarding technological performance are constantly increasing. An example of this is the growing consumption of multimedia content via the Internet. Multimedia applications with a variable number of users/requests have variable demand over time that may expose the limitation of the network channels. This may cause a problem of demand mobility generated by the service/application. Each generation of mobile networks has speciïŹc handover processes, which in the case of 4G can be controlled according to the applications requirements, with the possibility of multiconnectivity. This process was massiïŹed in 5G. The main contribution of this dissertation is the development and analysis of decision models for controlling the video streaming and user association to a BS in the network architecture. The scenario considered refers to a football stadium with multiple points of view – video streams – that each spectator can request to view on their cell phone or tablet. The developed simulator models the stadium scenario using a combination of services, which occur on the 5G network. Vertical handover generated by the network is used,aidedbynetworkslicing. Thenetworkslicingactsinthepartofthebandwidthdivision between the diïŹ€erent antennas and allows the throughput of the diïŹ€erent broadcast (FeMBMS)channelsto becontrolledbytheservice -theradionetworkcapacitylimitsthe throughput. The results obtained in a case of 80000 spectators who select diïŹ€erent beams over time, considering8basestations(BS),showthatthequalityofexperienceishighonlywhenthe handover and the control of beam diïŹ€usion by BS are managed according to the application requirements. The network recovers from huge peaks by handling as many requests at once as possible. Instead of the user only getting the steam in a good quality or not getting it at all, the network performs a best-eïŹ€ort solution of downgrading the quality of multicasting in order to expend less resources with the same quantity of requests. The network state is taken into consideration. Although there are load peaks on the network, it is never congested.Atualmente, as expectativas dos utilizadores em relação Ă  capacidade tecnolĂłgica nĂŁo param de aumentar. Exemplo disso Ă© o crescente consumo de conteĂșdo multimĂ©dia atravĂ©s da Internet. AplicaçÔes multimĂ©dia com nĂșmero variĂĄvel de utilizadores e pedidos tĂȘm um ïŹ‚uxo de serviço variĂĄvel ao longo do tempo. Esta variĂąncia pode expor a limitação de canais de rede, que consequentemente pode causar um problema de mobilidade gerado pelo serviço/aplicação. Cada geração de redes mĂłveis possui processos de handover de utilizadores especĂ­ïŹcos, que no caso da geração 4G passou a ser controlado em função das aplicaçÔes, com a possibilidade de multiconectividade. Este processo foi massiïŹcado no 5G. A principal contribuição desta dissertação Ă© o desenvolvimento e anĂĄlise de modelos de decisĂŁo para controlar a difusĂŁo de vĂ­deo e a associação de utilizadores Ă  rede rĂĄdio na arquitetura da rede. O cenĂĄrio considerado reïŹ‚ete um estĂĄdio de futebol com vĂĄrios pontos de vista - diferentes feixes de vĂ­deo - que cada espectador pode solicitar e visualizar no seu telemĂłvel ou tablet. O simulador desenvolvido modela o cenĂĄrio do estĂĄdio usando uma combinação de serviços, que ocorrem na rede 5G. É usado handover vertical gerado pela rede auxiliado por network slicing que atua na parte da divisĂŁo da largura de banda entre as diferentes antenas e permite que a taxa de dĂ©bito dos diferentes canais de difusĂŁo (FeMBMS) seja controlada pelo serviço - a capacidade da rede rĂĄdio limita a taxa de transferĂȘncia. Os resultados obtidos no caso de 80000 espectadores que selecionam diferentes feixes ao longo do tempo, considerando 8 estaçÔes base (BS), mostram que a qualidade de experiĂȘncia somente Ă© elevada quando o handover e o controlo da difusĂŁo de feixes pelas BS sĂŁo geridos de acordo com os requisitos da aplicação. A rede recupera a estabilidade apĂłs enormes picos de transferĂȘncia gerindo os seus recursos. Em vez do utilizador ser prejudicado na totalidade quando a rede nĂŁo tem recursos e ser privado de obter serviço, Ă© utilizado um processo alternativo em que a rede diminui a qualidade de multicasting, gastando menos recursos com a mesma quantidade de pedidos. O estado da rede Ă© sempre tido em consideração - embora hajam picos de carga na rede, esta nunca ïŹca congestionada

    Models and Methods for Network Selection and Balancing in Heterogeneous Scenarios

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    The outbreak of 5G technologies for wireless communications can be considered a response to the need for widespread coverage, in terms of connectivity and bandwidth, to guarantee broadband services, such as streaming or on-demand programs offered by the main television networks or new generation services based on augmented and virtual reality (AR / VR). The purpose of the study conducted for this thesis aims to solve two of the main problems that will occur with the outbreak of 5G, that is, the search for the best possible connectivity, in order to offer users the resources necessary to take advantage of the new generation services, and multicast as required by the eMBMS. The aim of the thesis is the search for innovative algorithms that will allow to obtain the best connectivity to offer users the resources necessary to use the 5G services in a heterogeneous scenario. Study UF that allows you to improve the search for the best candidate network and to achieve a balance that allows you to avoid congestion of the chosen networks. To achieve these two important focuses, I conducted a study on the main mathematical methods that made it possible to select the network based on QoS parameters based on the type of traffic made by users. A further goal was to improve the computational computation performance they present. Furthermore, I carried out a study in order to obtain an innovative algorithm that would allow the management of multicast. The algorithm that has been implemented responds to the needs present in the eMBMS, in realistic scenarios
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