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Wireless communication systems are prone to many security breaches due to open nature of the medium and exponential a rise in subscribers. Hence, physical layer security (PLS) has emerged as one of the dominant low complexity alternatives to overcome the impact of eavesdropping by managing the physical characteristics of the medium. In this paper, we ensure PLS to moving users which tends to experience rise in handover, as a result of proximity between users and base station. This study is based on ultra-dense network (UDN). To tackle this challenge, novel secure beamforming named as beam broadening and beam merging have been proposed. Besides, we propose a synchronization approach called synchronized mobility clustering for UDN to reduce the overheads generated due to the exchange of information about moving users. More specifically, we derive an analytical expression for secrecy outage probability—an important security metric. The effect of proposed approaches have been validated through numerical results and the results show the effectiveness of the proposed approaches against eavesdropping. Finally, the performance of the proposed scheme is evaluated and compared with the conventional beamforming approach. However, this proposed approach works well for a varied density of users and location to be targeted.
相似文献The Internet of Things (IoT) embodies the confluence of the virtual & physical world. IoT will play an important role in managing the managing depleting resource such as water, fuel, food, etc. However, to realize these applications enormous IoT devices will communicate with each other. This massive connectivity will directly or indirectly aid in Green House Gas emissions. Hence, to admissibly reduce this environmental impact of IoT, it must be greened in terms of energy consumption. Green IoT will reduce environmental exploitation by slashing carbon emission effectively and thus will help in achieving sustainability of the planet. This paper describes the journey of IoT to Green IoT. Along with this, the survey on recent Green-IoT techniques that will effectively help in reducing required energy consumption is presented. Along with this ability of unmanned aerial vehicle (UAV) technology to provide Green IoT and survey on recent energy-efficient UAV assisted communication is presented. In addition to this, a dual battery enabled Unmanned Aerial vehicle base station, an energy-efficient clustering algorithm, has also been proposed to prolong the battery life.
相似文献Today P2P (Peer-to-Peer) networks are gaining popularity for sharing the contents. Due to massive spreading of Internet, these networks are also growing fast. MP2P (Mobile P2P) networks are attracting many users due to increase in the Internet-based mobile applications. These networks suffer from many challenges which are not considered for analysis and modelling adequately. We focus on few challenges like mobility of users, churn rate, intermittent bandwidth, shorter life span of mobile nodes, stabilization of finger table, etc. in this paper. We analytically analyse these challenges and define the effects of different parameters over the performance. Traditional P2P protocols are designed for wired networks and when these are implemented for mobile networks then mobility effect of users adds more challenge for researchers. We select two types of mobility models namely FF (Fluid Flow) and RWP (Random Waypoint) models to model the users’ mobility. The churn rate of the mobile nodes makes network overlay management and content searching more difficult in MP2P networks. We select finger table-based protocols which are widely deployed in the P2P networks. But these protocols can’t perform well in the mobile P2P networks due to mobility of the users. The mobility of the users and churn rate of the mobile nodes create failure in lookup of finger table and induce more cost to update the finger table. We consider these challenges and quantify the failure rate of mobile nodes, life span of mobile nodes, available bandwidth, cost of stabilization of finger table per node, etc. in this proposal. The proposed model is useful for modelling the performance of MP2P networks performance in various wireless environments like Mobile Ad hoc Networks (MANETs), Wireless Mesh Networks (WMNs), Wireless Sensor Networks (WSNs), Vehicular Ad hoc Networks (VANETs), Wireless LAN (WLAN), Wireless MAN (WMAN), etc.
相似文献Pulmonary tuberculosis (PTB) is a contagious disease that affects the lung region. PTB is a life-threatening disease if it is detected late or left untreated. To perform the initial screening of PTB, the World Health Organization has recommended chest radiograph. Till now, the screening process requires either the patients to come to secondary health centers from rural areas or the radiologists to go the remote locations. This process is rejuvenated with the introduction of computer-aided diagnosis (CAD) systems. CAD systems reduce the need for expert radiologists in the screening process. However, the development and deployment are still in the early phases as new methods are being developed to improve the performance of CAD systems in terms of accuracy, specificity and sensitivity. In this study, a deep learning-based PTB classification system has been presented that achieves the state-of-the-art performance for TB classification. Firstly, a proposed architecture based on the blocks is presented and then it is used to create an ensemble. In the proposed ensemble, two standard architectures namely AlexNet, and ResNet have also been used in addition to the proposed architecture. All the architectures are trained and evaluated on a combined dataset formed using publicly available standard datasets. The proposed ensemble attains the accuracy of 90.00% and area under the curve equal to 0.96, which is better than the performance of the existing methods.
相似文献The paper presents the wide range phase-locked loop design for serializer. Serializer converts the 16 bit parallel data into serial, thus 16 times fast clock is required to synchronize the parallel data and serial data. PLL generates 16× serial clock from the parallel clock by frequency multiplication. PLL is simulated with 0.18 µm CMOS process. Major challenge of PLL design is to achieve large dynamic range. The PLL design for large dynamic range suffers from a high jitter at lower frequency and linearity issues. Advance CSVCO has been simulated with source degeneration technique and achieve wide linear range from 14 MHz to 1.05 GHz with 99.2 % linearity. The PVT Corners simulation shows 16 MHz to 1.04 GHz output range. Average power dissipation of the proposed PLL design is 2.7 mW. Worst case Peak to peak period jitter is 13.4 ps and rms jitter is 2.6 ps for 800 MHz output frequency.
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