1,005 research outputs found

    Hybrid Satellite-Terrestrial Communication Networks for the Maritime Internet of Things: Key Technologies, Opportunities, and Challenges

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    With the rapid development of marine activities, there has been an increasing number of maritime mobile terminals, as well as a growing demand for high-speed and ultra-reliable maritime communications to keep them connected. Traditionally, the maritime Internet of Things (IoT) is enabled by maritime satellites. However, satellites are seriously restricted by their high latency and relatively low data rate. As an alternative, shore & island-based base stations (BSs) can be built to extend the coverage of terrestrial networks using fourth-generation (4G), fifth-generation (5G), and beyond 5G services. Unmanned aerial vehicles can also be exploited to serve as aerial maritime BSs. Despite of all these approaches, there are still open issues for an efficient maritime communication network (MCN). For example, due to the complicated electromagnetic propagation environment, the limited geometrically available BS sites, and rigorous service demands from mission-critical applications, conventional communication and networking theories and methods should be tailored for maritime scenarios. Towards this end, we provide a survey on the demand for maritime communications, the state-of-the-art MCNs, and key technologies for enhancing transmission efficiency, extending network coverage, and provisioning maritime-specific services. Future challenges in developing an environment-aware, service-driven, and integrated satellite-air-ground MCN to be smart enough to utilize external auxiliary information, e.g., sea state and atmosphere conditions, are also discussed

    Performance and energy efficiency in wireless self-organized networks

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    Performance Analysis of Multiple Access Techniques for LTE system under Symbol Error Rate (SER) Calculation

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    In the recent years, so many technologies in multiple access trends have influenced the field of Wireless Sensor Networks in significant ways. Various trends are readily available technology of ubiquitous wireless sensor networks as well as wireless communication networks and progress in the development of two multiple access techniques are compared in this scenario: the OFDMA and SC-FDMA. The OFDMA and SC-FDMA transceivers are modeled and simulated considering both the interleaved and localized subcarriers mapping schemes. WSNs have the potentiality to connect the physical world with the virtual world by forming a network of sensor nodes. To prolong the networklsquo;s hop in terms of single and two hop using both techniques should be used in the sensor nodes. The minimization of computing and storage platforms as well as the development of novel micro sensors and sensor materials with high reliability force encourages technology in research on WSN. In this paper, we will proposed the field of multipath routing in wireless sensor networks, and mainly focus on the technology of SER of WSNs

    Power Efficient Location Aware Routing Protocol to Improve Routing in MANET

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    The Mobile Adhoc network (MANET) uses the concept of dynamic topology in the wireless network. The major noteworthy issues in construction of MANET are the energy consumption by the nodes. According to the requirement of present situation a variety of energy efficient routing protocol has been suggested that helps in increasing the lifetime of the network. Emerging Trends in energy efficient routing protocols as the name suggest recognize that many approaches like clustered, genetic algorithm (GA) and so many has came in existence that helps in growing the network lifetime of energy efficient routing protocols. In this paper we proposed a novel Power Efficient Location Aware Routing (PELAR) protocol. In this protocol energy dependent nodes are growing the routing ability of AODV protocol on the source of LAR (Location Aided Routing) protocol. In network nodes are not aware about their energy status and also return flooding of routing packets is utilizes extra energy in network by that the bulk of the energy is exhausted in handshaking process. The main attempt of proposed PELAR protocol is to obtain improved the energy utilization in network. The performance of usual AODV, LAR and PELAR is show via simulation implemented on NS2 and observe that the proposed PELAR protocol decreases the energy utilization and improve the network lifetime that completely depend on the energy of mobile nodes. Keywords: AODV, Energy Efficiency, LAR, MANET, Routing protocol

    Katakan tidak pada rasuah

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    Isu atau masalah rasuah menjadi topik utama sama ada di peringkat antarabangsa mahupun di peringkat dalam negara. Pertubuhan Bangsa- bangsa Bersatu menegaskan komitmen komuniti antarabangsa bertegas untuk mencegah dan mengawal rasuah melalui buku bertajuk United Nations Convention against Corruption. Hal yang sama berlaku di Malaysia. Melalui pernyataan visi oleh mantan Perdana Menteri Malaysia, Tun Dr. Mahathir bin Mohamed memberikan indikasi bahawa kerajaan Malaysia komited untuk mencapai aspirasi agar Malaysia dikenali kerana integriti dan bukannya rasuah. Justeru, tujuan penulisan bab ini adalah untuk membincangkan rasuah dari beberapa sudut termasuk perbincangan dari sudut agama Islam, faktor-faktor berlakunya gejala rasuah, dan usaha-usaha yang dijalankan di Malaysia untuk membanteras gejala rasuah. Perkara ini penting bagi mengenalpasti penjawat awam menanamkan keyakinan dalam melaksanakan tanggungjawab dengan menghindari diri daripada rasuah agar mereka sentiasa peka mengutamakan kepentingan awam

    A Novel Energy Aware Clustering Mechanism with Fuzzy Logic in MANET Environment

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    A Mobile Ad Hoc Networks (MANETs) comprises of the vast range of devices such as sensors, smart phones, laptops and other mobile devices that connect with each other across wireless networks and collaborate in a dispersed fashion to offer network functions in the absence of a permanent infrastructure. The Cluster Head (CH) selection in a clustered MANET is still crucial for lowering each node's energy consumption and increasing the network's lifetime. However, in existing clustering mechanism trust of the all nodes are presumed those causes increased challenge in the MANET environment. Security is a crucial factor when constructing ad-hoc networks. In a MANET, energy consumption in route optimization is dependent on network resilience and connectivity. The primary objective of this study is to design a reliable clustering mechanism for MANETs that takes energy efficiency into account. For trusted energy-efficient CH in the nodes, a safe clustering strategy integrating energy-efficient and fuzzy logic based energy clustering is proposed to address security problems brought about by malicious nodes and to pick a trustworthy node as CH. To improve the problem findings Bat algorithm (BAT) is integrated with Particle Swarm Optimization (PSO). The PSO technique is inspired because it imitates the sociological characteristics of the flock of the birds through random population. The BAT is a metaheuristic algorithm inspired by microbat echolocation behavior that uses pulse average with global optimization of the average path in the network. Hybrid Particle Swarm Optimization (HPSO) and BAT techniques are applied to identify the best route between the source and destination. According to the simulation results, the suggested Fuzzy logic Particle Swarm Optimization BAT (FLPSO-BAT) technique has a minimum latency of 0.0019 milliseconds, with energy consumption value of 0.09 millijoules, maximal throughput of 0.76 bits per sec and detection rate of 90.5% without packet dropping attack
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