4,843 research outputs found

    Opportunistic Networks: Present Scenario- A Mirror Review

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    Opportunistic Network is form of Delay Tolerant Network (DTN) and regarded as extension to Mobile Ad Hoc Network. OPPNETS are designed to operate especially in those environments which are surrounded by various issues like- High Error Rate, Intermittent Connectivity, High Delay and no defined route between source to destination node. OPPNETS works on the principle of “Store-and-Forward” mechanism as intermediate nodes perform the task of routing from node to node. The intermediate nodes store the messages in their memory until the suitable node is not located in communication range to transfer the message to the destination. OPPNETs suffer from various issues like High Delay, Energy Efficiency of Nodes, Security, High Error Rate and High Latency. The aim of this research paper is to overview various routing protocols available till date for OPPNETs and classify the protocols in terms of their performance. The paper also gives quick review of various Mobility Models and Simulation tools available for OPPNETs simulation

    Multi-Service Radio Resource Management for 5G Networks

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    PaFiR : Particle Filter Routing – a predictive relaying scheme for UAV-assisted IoT communications in future innovated networks

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    Increasing urbanization, smart cities and other cutting-edge technologies offer the prospect of providing more functions to benefit citizens by relying on the substantial data processing and exchange capabilities now possible. This can generate significant unpredictable and unbalanced data loads for the bearing IoT network to support its application and service demands. We thus propose a wireless routing scheme designed to use the Particle Filter algorithm to empower portable smart devices with intelligent capacities for the radio communication system. This facilitates the offloading of traffic from traditional wireless networks and enables the IoT system to adopt unmanned aerial vehicles, thus also offering further innovation to flying network platforms. The proposed PaFiR routing protocol offers the network more scalability, tolerance and resilience, to achieve the goal of smart relaying. Simulation results that demonstrate the routing algorithm designed offers excellent performance when compared with existing wireless relaying schemes. It provides delivery ratios that are improved by up to 40% without unmanageable increases in latency or overheads

    SCALABLE MULTI-HOP DATA DISSEMINATION IN VEHICULAR AD HOC NETWORKS

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    Vehicular Ad hoc Networks (VANETs) aim at improving road safety and travel comfort, by providing self-organizing environments to disseminate traffic data, without requiring fixed infrastructure or centralized administration. Since traffic data is of public interest and usually benefit a group of users rather than a specific individual, it is more appropriate to rely on broadcasting for data dissemination in VANETs. However, broadcasting under dense networks suffers from high percentage of data redundancy that wastes the limited radio channel bandwidth. Moreover, packet collisions may lead to the broadcast storm problem when large number of vehicles in the same vicinity rebroadcast nearly simultaneously. The broadcast storm problem is still challenging in the context of VANET, due to the rapid changes in the network topology, which are difficult to predict and manage. Existing solutions either do not scale well under high density scenarios, or require extra communication overhead to estimate traffic density, so as to manage data dissemination accordingly. In this dissertation, we specifically aim at providing an efficient solution for the broadcast storm problem in VANETs, in order to support different types of applications. A novel approach is developed to provide scalable broadcast without extra communication overhead, by relying on traffic regime estimation using speed data. We theoretically validate the utilization of speed instead of the density to estimate traffic flow. The results of simulating our approach under different density scenarios show its efficiency in providing scalable multi-hop data dissemination for VANETs

    Developing Universal Postal Services in Latin America – an Economic Perspective

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    The paper first analyzes if there is a need to develop universal postal services in developing countries. We conclude that postal services serve vital functions in economies now and for the foreseeable future. We then discuss regulatory remedies that will foster the evolution of universal postal services in developing countries.Developing Countries, Universal Postal Services

    Moving from the 'Why' to the 'How': Reflections on Humanitarian Response in urban settings

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    Given the rising numbers of crises in urban settings, Médecins Sans Frontières (MSF) is currently shifting its focus from 'why' it should intervene to 'how' it should intervene effectively in these contexts. Beyond communities affected by natural disasters and epidemics, MSF has chosen to target populations in urban settings that are affected by violence or by marginalisation and neglect: these groups appear to suffer the greatest number of severe threats to their health and well-being. Recent reflection within MSF has identified a number of key operational challenges to confront in order to respond efficiently to the needs of these populations. These include: appropriate assessments; measurable indicators of vulnerability and impact; pertinent operational approaches and medical strategies; adapted security management; and responsible closure of activities. This paper summarises the main lessons learned from working in urban settings with the principal aim of mutual sharing and understanding
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