14 research outputs found

    Performance Evaluation of Video Streaming in an Infrastructure Mesh Based Vehicle Network

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    Most next-generation wireless networks are expected to support video stream- ing which constitutes the bulk of traffic on the Internet. This thesis evaluates the performance of video streaming in a vehicle network with an infrastructure wireless mesh network (WMN) backhaul. Several studies have investigated video quality per- formance primarily in single hop wireless networks and static WMNs. This thesis is based on those studies and conducts the study in relation to a network where the multi-hop features of the mesh network and mobility of the streaming clients may have substantial impact on the perceived video quality in the network. The study assumes a previously proposed vehicle network architecture con- sisting of an infrastructure WMN that serves as the mesh backhaul [2, 3]. A number of mesh routers (MRs) form the mesh backhaul using one of their two IEEE 802.11g radios whereas the other radio is used to communicate with the fast moving mesh clients (MCs). Selective MRs called mesh gateways (MGs) are connected to a wired network (e.g., the Internet, hereafter referred to as the core network) via a point-to- point link and provide gateway connectivity to the rest of the network. A server on the core network acts as a video server and streams individual video streams to the fast moving MCs. Upon deployment, network discovery occurs and segregates the network into a number of separate routing zones with each routing zone consisting of a single MG and all the MRs that use the MG as their gateway. A minimum-hop based routing protocol is used to enable seamless handover of MCs from one MR to another within a single zone. Simulation studies in this thesis inspects the network and video streaming performance within a single routing zone, assuming the handoff and inter-zone routing being taken care of by the routing protocol and only focus on the intra-zone packet forwarding and scheduling impacts. Hence, this study does not address cases where MCs move from one routing zone to another routing zone in the mobile network. In the first part of the study, we evaluate the performance of video streaming in the described network by studying performance metrics across different layers of the protocol stack. The number of video flows that can be supported by the network is experimentally determined for each scenario. In the second part, the thesis studies controllable network and protocol parameters\u27 ability to improve the network and video quality performance. Simulations are run in an integrated framework that includes network-simulator ns-2, NS-MIRACLE, and Evalvid

    Media handling for conferencing in MANETs

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    Mobile Ad hoc NETworks (MANETs) are formed by devices set up temporarily to communicate without using a pre-existing network infrastructure. Devices in these networks are disparate in terms of resource capabilities (e.g. processing power, battery energy). Multihop Cellular Networks (MCNs) incorporate multihop mobile ad-hoc paradigms into 3G conventional single-hop cellular networks. Conferencing, an essential category of applications in MANETs and MCNs, includes popular applications such as audio/video conferencing. It is defined as an interactive multimedia service comprising online exchange of multimedia content among several users. Conferencing requires two sessions: a call signaling session and a media handling session. Call signaling is used to set up, modify, and tear down conference sessions. Media handling deals with aspects such as media transportation, media mixing, and transcoding. In this thesis, we are concerned with media handling for conferencing in MANETs and MCNs. We propose an architecture based on two overlay networks: one for mixing and one for control. The first overlay is composed of nodes acting as mixers. Each node in the network has a media connection with one mixer in the first overlay. A novel distributed mixing architecture that minimizes the number of mixers in end-to-end paths is proposed as an architectural solution for this first overlay. A sub-network of nodes, called controllers, composes the second overlay. Each controller controls a set of mixers, and collectively, they manage and control the two-overlay network. The management and control tasks are assured by a media signaling architecture based on an extended version of Megaco/H.L248. The two-overlay network is self-organizing, and thus automatically assigns users to mixers, controls mixers and controllers, and recovers the network from failures. We propose a novel self-organizing scheme that has three components: self-growing, self-shrinking and self-healing. Self-growing and self-shrinking use novel workload balancing schemes that make decisions to enable and disable mixers and controllers. The workload balancing schemes use resources efficiently by balancing the load among the nodes according to their capabilities. Self-healing detects failed nodes and recovers the network when failures of nodes with responsibilities (mixers and controllers) occur. Detection of failed nodes is based on a novel application-level failure detection architecture. A novel architecture for media handling in MCNs is proposed. We use mediator concepts to connect the media handling entities of a MANET with the media entities of a 3G cellular network. A media mediator assures signaling and media connectivity between the two networks and acts as a translator of the different media handling protocols

    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

    Internet of Things and Sensors Networks in 5G Wireless Communications

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    This book is a printed edition of the Special Issue Internet of Things and Sensors Networks in 5G Wireless Communications that was published in Sensors

    Internet of Things and Sensors Networks in 5G Wireless Communications

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    This book is a printed edition of the Special Issue Internet of Things and Sensors Networks in 5G Wireless Communications that was published in Sensors

    Internet of Things and Sensors Networks in 5G Wireless Communications

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    The Internet of Things (IoT) has attracted much attention from society, industry and academia as a promising technology that can enhance day to day activities, and the creation of new business models, products and services, and serve as a broad source of research topics and ideas. A future digital society is envisioned, composed of numerous wireless connected sensors and devices. Driven by huge demand, the massive IoT (mIoT) or massive machine type communication (mMTC) has been identified as one of the three main communication scenarios for 5G. In addition to connectivity, computing and storage and data management are also long-standing issues for low-cost devices and sensors. The book is a collection of outstanding technical research and industrial papers covering new research results, with a wide range of features within the 5G-and-beyond framework. It provides a range of discussions of the major research challenges and achievements within this topic
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