فهرست مقالات Base Station

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  1 - Clustering for Reduction of Energy Consumption in Wireless Sensor Networks by AHP Method
  Mohammad Reza  Taghva Robab  Hamlbarani Haghi Aziz Hanifi Kamran  feizi
  10.7508/jist.2018.21.002
  Due to the type of applications, wireless sensor nodes must always be energy efficient and small. Hence, some studies have been done in order to the reduction in energy consumption. Data collection in wireless sensor networks is one of the most important operations of t چکیده کامل

  Due to the type of applications, wireless sensor nodes must always be energy efficient and small. Hence, some studies have been done in order to the reduction in energy consumption. Data collection in wireless sensor networks is one of the most important operations of these networks. Due to the energy limitation of nodes, energy efficiency is considered as a key objective in the design of sensor networks. In this paper, we present a method in which, in the first phase, nodes obtain their position by using the position of the base station and two other two nodes informed geographic position and are out of covered environment. In the second phase, the optimal location of the base station is determined. In the third phase, we determine the cluster heads based on the criteria such as the remaining energy, the distance (the distance from the cluster head and the distance from the base station), the number of neighbors (the one-step neighbors and the two-step neighbors) and the centrality. Using the multi-as criteria to select optimally cluster heads by decision making method. We implement the proposed method in the NS2 environment and evaluate its effect and compare it with the NEECP E-LEACH protocols. Simulation results show that by reducing energy consumption, the proposed method enhances the network life time expectancy. In addition it improves average packet delivery and the average delay. پرونده مقاله
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  2 - Lifetime Improvement Using Cluster Head Selection and Base Station Localization in Wireless Sensor Networks
  maryam najimi Sajjad  Nankhoshki
  10.7508/jist.2018.02.006
  The limited energy supply of wireless sensor networks poses a great challenge for the deployment of wireless sensor nodes. In this paper, a sensor network of nodes with wireless transceiver capabilities and limited energy is considered. Clustering is one of the most eff چکیده کامل

  The limited energy supply of wireless sensor networks poses a great challenge for the deployment of wireless sensor nodes. In this paper, a sensor network of nodes with wireless transceiver capabilities and limited energy is considered. Clustering is one of the most efficient techniques to save more energy in these networks. Therefore, the proper selection of the cluster heads plays important role to save the energy of sensor nodes for data transmission in the network. In this paper, we propose an energy efficient data transmission by determining the proper cluster heads in wireless sensor networks. We also obtain the optimal location of the base station according to the cluster heads to prolong the network lifetime. An efficient method is considered based on particle swarm algorithm (PSO) which is a nature inspired swarm intelligence based algorithm, modelled after observing the choreography of a flock of birds, to solve a sensor network optimization problem. In the proposed energy- efficient algorithm, cluster heads distance from the base station and their residual energy of the sensors nodes are important parameters for cluster head selection and base station localization. The simulation results show that our proposed algorithm improves the network lifetime and also more alive sensors are remained in the wireless network compared to the baseline algorithms in different situations. پرونده مقاله
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  3 - An Analysis of the Signal-to-Interference Ratio in UAV-based Telecommunication Networks
  hamid jafaripour Mohammad Fathi
  10.61186/jist.40342.12.45.49
  One of the most important issues in wireless telecommunication systems is to study coverage efficiency in urban environments. Coverage efficiency means improving the signal-to-interference ratio (SIR) by providing a maximum telecommunication coverage and establishing hi چکیده کامل

  One of the most important issues in wireless telecommunication systems is to study coverage efficiency in urban environments. Coverage efficiency means improving the signal-to-interference ratio (SIR) by providing a maximum telecommunication coverage and establishing high-quality communication for users. In this paper, we use unmanned aerial vehicle (UAVs) as air base stations (BS) to investigate and improve the issue of maximizing coverage with minimal interference. First, we calculate the optimal height of the UAVs for the coverage radius of 400, 450, 500, 550, and 600 meters. Then, using simulation, we calculate and examine the value and status of SIR in UAVs with omnidirectional and directional antenna modes in symmetric and asymmetric altitude conditions, with and without considering the height of the UAVs. The best SIR is the UAV system with a directional antenna in asymmetric altitude conditions where the SIR range varies from 4.44db (the minimum coverage) to 52.11dB (maximum coverage). The worst SIR is the UAV system with an omnidirectional antenna in symmetrical height conditions without considering the height of the UAV. We estimate the range of SIR changes for different coverage ranges between 1.39 and 28dB. Factors affecting the SIR values from the most effective to the least, respectively, are coverage range and the antenna type, symmetrical and asymmetric height, and finally, considering or not considering the height of the UAV. پرونده مقاله
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  4 - تامین توان الکتریکی ایستگاه¬های مخابرات سلولی در ریزشبکه-های مجزا با اولویت بکارگیری منابع تجدیدپذیر و خودروهای الکتریکی با ارائه رویکرد برنامه¬ریزی غیرخطی مختلط با اعداد صحیح
  رضا   بحری سعید زینالی
  این مقاله، موضوع تامین توان اقتصادی و زیست محیطی برای ایستگاه های مخابرات سلولی در یک ریزشبکه مجزای مستقر در مناطق صعب العبور را مورد بررسی قرار داده است. ریزشبکه، شامل ژنراتوردیزلی، سیستم فتوولتاییک و منبع ذخیره هیدروژنی است. امکان تبادل انرژی ریزشبکه با باتری خودرو ال چکیده کامل

  این مقاله، موضوع تامین توان اقتصادی و زیست محیطی برای ایستگاه های مخابرات سلولی در یک ریزشبکه مجزای مستقر در مناطق صعب العبور را مورد بررسی قرار داده است. ریزشبکه، شامل ژنراتوردیزلی، سیستم فتوولتاییک و منبع ذخیره هیدروژنی است. امکان تبادل انرژی ریزشبکه با باتری خودرو الکتریکی متصل شده به ریزشبکه، مورد بررسی قرار گرفت. با استفاده از شارژ/دشارژ هوشمند خودروهای الکتریکی تامین توان المان های ریزشبکه، صورت گرفته شده و حداکثر استفاده از انرژی های پاک به عمل آمده است. مدل ریاضی مسئله فوق به عنوان یک برنامه ریزی غیرخطی مختلط با اعداد صحیح ارئه شد که ماهیت غیرخطی المان ها را مدلسازی می کند. در قالب بهینه سازی چندهدفه، بجز هزینه، گازهای گلخانه ای نیز از اهداف مسئله بوده و تعادلی بین این دو هدف متناقض در جبهه پارتو ایجاد شده است. در این مسئله، پارامتر های غیرقطعی، مانند تولید انرژی خورشیدی، الگو های رفتاری راننده ها (زمان رسیدن به ایستگاه شارژ، زمان خروج از ایستگاه شارژ، و مسافت روزانه طی شده، تولید) توسط سناریو های تصادفی مدلسازی شده است. نتایج به دست آمده نشان می دهد که شارژ/دشارژ هوشمند خودروهای الکتریکی، سهم چشمگیری در کاهش ریسک عملیاتی ریزشبکه، هزینه ی کل و گازهای گلخانه ای دارد. به طوریکه، استفاده از روش برنامه ریزی اقتصادی/زیست-محیطی پیشنهاد شده، منجر به %60/18 کاهش در مقدار گازهای گلخانه ای می شود. پرونده مقاله