cellular system
Recently Published Documents


TOTAL DOCUMENTS

956
(FIVE YEARS 81)

H-INDEX

34
(FIVE YEARS 2)

Author(s):  
Mohamed Elhattab ◽  
Mohamed Amine Arfaoui ◽  
Chadi Assi ◽  
Ali Ghrayeb

Author(s):  
Nour El-Din Safwat ◽  
Fatma Newagy ◽  
Ismail Hafez

In this paper, a new relay system that uses the UAV as a relay station between the tethered UAV and ground user (TU2U2G) is proposed. The TU2U2G system replaces the base station (BS) in the cellular system with a tethered UAV (TUAV). The TUAV is a UAV that receives power over a cable from a ground control station. It has advantages of high and variable altitude up to (100m) compared to BS. In addition, it overcomes the UAV drawback of the batteries' limited capacity. After that, a 3D placement Algorithm of the UAV as a relay station in the TU2U2G system is proposed. It is presented to maximize the coverage by jointly optimizing the transmitting power and relaying distance. The TU2U2G system shows better results than the traditional cellular system in terms of optimum UAV height, maximum coverage radius, and maximum distance between BS and UAV.


Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2953
Author(s):  
Sudheesh Puthenveettil Gopi ◽  
Maurizio Magarini

The application of unmanned aerial vehicles (UAV) as base station (BS) is gaining popularity. In this paper, we consider maximization of the overall data rate by intelligent deployment of UAV BS in the downlink of a cellular system. We investigate a reinforcement learning (RL)-aided approach to optimize the position of flying BSs mounted on board UAVs to support a macro BS (MBS). We propose an algorithm to avoid collision between multiple UAVs undergoing exploratory movements and to restrict UAV BSs movement within a predefined area. Q-learning technique is used to optimize UAV BS position, where the reward is equal to sum of user equipment (UE) data rates. We consider a framework where the UAV BSs carry out exploratory movements in the beginning and exploitary movements in later stages to maximize the overall data rate. Our results show that a cellular system with three UAV BSs and one MBS serving 72 UE reaches 69.2% of the best possible data rate, which is identified by brute force search. Finally, the RL algorithm is compared with a K-means algorithm to study the need of accurate UE locations. Our results show that the RL algorithm outperforms the K-means clustering algorithm when the measure of imperfection is higher. The proposed algorithm can be made use of by a practical MBS–UAV BSs–UEs system to provide protection to UAV BSs while maximizing data rate.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Julius Yaw Ludu ◽  
Justice Kwame Appati ◽  
Ebenezer Owusu ◽  
Prince Boakye-Sekyerehene

The proposal of LTE in the standardization of cellular network systems has received considerable attention in the research domain, and most subscribers widely use it. Despite the enormous acceptance of the system, academia as an industry is usually disadvantaged in training students due to the cost implication in setting up a prototype. In bridging this gap, simulators are traditionally developed as a testbed to aid students appreciate how these systems work. Although there are several simulators available on the market, these simulators are quite expensive to acquire while others come with license restrictions. In this study, a classical LTE cellular system simulator is proposed as a testbed to aid the education of computer networks at college. The proposed simulator is an extension of the functionality of LTE-Sim frameworks. Usability testing of the proposed study reveals that the system is much easier to simulate the various scenarios in wireless communication.


2021 ◽  
Author(s):  
Xolani Henry Makhoba

Malaria remains a threat to human life worldwide with children under the age of 5 being the most vulnerable. Plasmodium falciparum, known as the causative agent of the deadliest malaria, survives both in the mosquito vector and human host. The sudden temperature change seems to not affect the parasite’s cellular system. Heat shock proteins and polyamines are the major house-keepers of the parasite’s cellular system to remain viable, despite the temperature changes that the parasite gets exposed to. While heat shock proteins protect newly synthesized proteins until they are properly folded polyamines are needed for cell differentiation, proliferation, and cell growth. In plants for example, polyamines have been reported to act as molecular chaperones when cells are exposed to unfavorable conditions that could be detrimental to cells. In this review, the role of heat shock proteins and polyamines in plasmodium parasite drug resistance and their role in parasite survival are discussed. The current drugs against malaria as well as the alternative future approach towards malarial drug development are reviewed.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ritesh K Shukla ◽  
Ashish Badiye ◽  
Kamayani Vajpayee ◽  
Neeti Kapoor

The rapid advancement of nanotechnology enhances the production of different nanoparticles that meet the demand of various fields like biomedical sciences, industrial, material sciences and biotechnology, etc. This technological development increases the chances of nanoparticles exposure to human beings, which can threaten their health. It is well known that various cellular processes (transcription, translation, and replication during cell proliferation, cell cycle, cell differentiation) in which genetic materials (DNA and RNA) are involved play a vital role to maintain any structural and functional modification into it. When nanoparticles come into the vicinity of the cellular system, chances of uptake become high due to their small size. This cellular uptake of nanoparticles enhances its interaction with DNA, leading to structural and functional modification (DNA damage/repair, DNA methylation) into the DNA. These modifications exhibit adverse effects on the cellular system, consequently showing its inadvertent effect on human health. Therefore, in the present study, an attempt has been made to elucidate the genotoxic mechanism of nanoparticles in the context of structural and functional modifications of DNA.


2021 ◽  
Vol 9 (8) ◽  
pp. 910
Author(s):  
Stylianos Alexakis ◽  
Christos Tsabaris

Ocean in-situ sensors are crucial for measuring oceanic parameters directly from the sea in a spatial and temporal basis. Real-time operation is used in many applications related to decision support tools and early warning services in case of accidents, incidents and/or disasters. The design of the proposed system is described as a rapid-response detection system, which aims to measure natural and artificial radioactive contaminants or other crucial ocean parameters, to replace the traditional method of sampling. The development of an interactive cellular system is undertaken using a commercial router that is programmed according to sensor specifications. A radioactivity sensor is integrated in a communication box enabling self-powered operation with a solar panel. The proposed system operates in (near) real-time mode and provides gamma-ray spectra by integrating the sensor and the appropriate electronic modules in it. Additionally, an on-site experiment was conducted to test the operability of the system in a real environment close to the sea, for monitoring fallout due to rainfall and snowfall events. The main intense radionuclides that were observed by different energy lines, were radon progenies (214Bi, 214Pb). The continuous operation of the whole system was controlled by operating the system during the winter period.


Author(s):  
Mohamed El Sayed Kotb ◽  
Wagdy R. Anis ◽  
Ahmed A. Abd-Elhafez
Keyword(s):  

Author(s):  
Mohammed Salah Abood ◽  
Ahmed Shamil Mustafa ◽  
Hussain Falih Mahdi ◽  
Al-Fakih Ali Mohammed ◽  
Mustafa Maad Hamdi ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document