scholarly journals On the Performance of a UAV-Aided Wireless Network Based on NB-IoT

Drones ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 94
Author(s):  
Silvia Mignardi ◽  
Riccardo Marini ◽  
Roberto Verdone ◽  
Chiara Buratti
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Network Performance ◽  
Narrow Band ◽  
Base Station ◽  
Research Community ◽  
Technical Aspects ◽  
Access Rate ◽  
Numerical Assessment ◽  
The Many ◽  
The Impact

In recent years, interest in Unmanned Aerial Vehicles (UAVs) as a means to provide wireless connectivity has substantially increased thanks to their easy, fast and flexible deployment. Among the several possible applications of UAV networks explored by the current literature, they can be efficiently employed to collect Internet-of-Things (IoT) data because the non-stringent latency and small-size traffic type is particularly suited for UAVs’ inherent characteristics. However, the implications coming from the implementation of existing technology in such kinds of nodes are not straightforward. In this article, we consider a Narrow Band IoT (NB-IoT) network served by a UAV base station. Because of the many configurations possible within the NB-IoT standard, such as the access structure and numerology, we thoroughly review the technical aspects that have to be implemented and may be affected by the proposed UAV-aided IoT network. For proper remarks, we investigate the network performance jointly in terms of the number of successful transmissions, access rate, latency, throughput and energy consumption. Then, we compare the obtained results on different and known trajectories in the research community and study the impact of varying UAV parameters such as speed and height. Moreover, the numerical assessment allows us to extend the discussion to the potential implications of this model in different scenarios. Thus, this article summarizes all the main aspects that must be considered in planning NB-IoT networks with UAVs.

THE IMPACT OF MESSAGE-BUFFER ALIGNMENT ON COMMUNICATION PERFORMANCE

2005 ◽  
Vol 15 (01n02) ◽  
pp. 49-65 ◽  
Author(s):  
LEON ARBER ◽  
SCOTT PAKIN
Keyword(s):  
Network Performance ◽  
Performance Test ◽  
Careful Analysis ◽  
Communication Performance ◽  
Accepted Practice ◽  
The Many ◽  
Performance Discrepancy ◽  
Relationship Of ◽  
The Impact

Of the many factors that contribute to communication performance, perhaps one of the least investigated is that of message-buffer alignment. Although the generally accepted practice is to page-align buffer memory for best performance, our studies show that the actual relationship of buffer alignment to communication performance cannot be expressed with such a simple formula. This paper presents a case study in which porting a simple network performance test from one language to another resulted in a large performance discrepancy even though both versions of the code consist primarily of calls to messaging-layer functions. Careful analysis of the two code versions revealed that the discrepancy relates to the alignment in memory of the message buffers. Further investigation revealed some surprising results about the impact of message-buffer alignment on communication performance: (1) different networks and node architectures prefer different buffer alignments; (2) page-aligned memory does not always give the best possible performance, and, in some cases, actually yields the worst possible performance; and, (3) on some systems, the most significant factor affecting network performance is the relative alignment of send and receive buffers with respect to each other.

scholarly journals Performance Analysis of Backhaul-Aware User Association in 5G Ultradense Heterogeneous Networks

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Junpeng Yu ◽  
Hongtao Zhang ◽  
Yuqing Chen ◽  
Yaduan Ruan
Keyword(s):  
Heterogeneous Networks ◽  
Association Scheme ◽  
Coverage Probability ◽  
Network Performance ◽  
Performance Metrics ◽  
Density Ratio ◽  
Base Station ◽  
Base Stations ◽  
User Association ◽  
The Impact

In 5G ultradense heterogeneous networks, wireless backhaul, as one of the important base station (BS) resources that affect user services, has attracted more and more attention. However, a user would access to the BS which is the nearest for the user based on the conventional user association scheme, which constrains the network performance improvement due to the limited backhaul capacity. In this paper, using backhaul-aware user association scheme, semiclosed expressions of network performance metrics are derived in ultradense heterogeneous networks, including coverage probability, rate coverage, and network delay. Specifically, all possible access and backhaul links within the user connectable range of BSs and anchor base stations (A-BSs) are considered to minimize the analytical results of outage probability. The outage for the user occurs only when the access link or backhaul link which forms the link combination with the optimal performance is failure. Furthermore, the theoretical analysis and numerical results evaluate the impact of the fraction of A-BSs and the BS-to-user density ratio on network performance metric to seek for a more reasonable deployment of BSs in the practical scenario. The simulation results show that the coverage probability of backhaul-aware user association scheme is improved significantly by about 2× compared to that of the conventional user association scheme when backhaul is constrained.

scholarly journals Heterogeneous networks: Fair power allocation in LTE-A uplink scenarios

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252421
Author(s):  
Reben Kurda
Keyword(s):  
Power Control ◽  
Heterogeneous Networks ◽  
Spectral Efficiency ◽  
Network Performance ◽  
Fractional Power ◽  
Base Station ◽  
Small Cells ◽  
Lte Networks ◽  
Control Approach ◽  
The Impact

Effective management of radio resources and service quality assurance are two of the essential aspects to furnish high-quality service in Long Term Evolution (LTE) networks. Despite the base station involving several ingenious scheduling schemes for resource allocation, the intended outcome might be influenced by the interference, especially in heterogeneous scenarios, where many kinds of small cells can be deployed under the coverage of macrocell area. To develop the network of small cells, it is essential to take into account such boundaries, in particular, mobility, interference and resources scheduling a strategy which assist getting a higher spectral efficiency in anticipate small cells. Another challenge with small cellular network deployment is further analyzing the impact of power control techniques in the uplink direction for the network performance. With that being said, this article investigates the problem of interference in LTE-advanced heterogeneous networks. The proposed scheme allows mitigation inter-cell interference through fractional self-powered control performed at each femtocell user. This study analyzes a scheme with optimum power value that provides a compromise between the served uplink signal within unwanted interference plus noise ratio to enhance spectral efficiency in terms of throughput. In particular, the maximum transmit power for user equipment in uplink direction should be reviewed for small cells as a major contributor to the interference. The simulation results showed that the proposed fractional power control approach can outperform the traditional power control employed as a full compensation mode in small cell uplinks.

scholarly journals Network Performance Evaluation of Abis Interface over DVB-S2 in the GSM over Satellite Network

2010 ◽  
Vol 2010 ◽  
pp. 1-8
Author(s):  
S. B. Musabekov ◽  
P. K. Srinivasan ◽  
A. S. Durai ◽  
R. R. Ibraimov
Keyword(s):  
Network Performance ◽  
Cost Effective ◽  
Base Station ◽  
Satellite Network ◽  
Channel Network ◽  
Network Availability ◽  
Link Budget ◽  
Base Transceiver Station ◽  
Gsm Network ◽  
The Impact

This paper deals with establishing a GSM link over Satellite. Abis interface, which is defined between Base Transceiver Station (BTS) and Base Station Controller (BSC), in a GSM network is considered here to be routed over the Satellite. The satellite link enables a quick and cost-effective GSM link in meagerly populated areas. A different scenario comparison was done to understand the impact of Satellite environment on network availability comparing to terrestrial scenario. We have implemented an Abis interface over DVB S2 in NS2 and evaluated the performance over the high delay and loss satellite channel. Network performance was evaluated with respect to Satellite channel delay and DVB S2 encapsulation efficiency under different amount of user traffic and compared with the terrestrial scenario. The results clearly showed an increased amount of SDCCH and TCH channels required in the case of satellite scenario for the same amount of traffic in comparison to conventional terrestrial scenario. We have optimized the parameters based on the simulation results. Link budget estimation considering DVB-S2 platform was done to find satellite bandwidth and cost requirements for different network setups.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

The impact of cultural factors on attachment dynamics: a view from Irish society

2019 ◽  
Vol 13 (2) ◽  
pp. 207-223
Author(s):  
Michael O’Toole
Keyword(s):  
Significant Role ◽  
Emotional Development ◽  
Cultural Factors ◽  
Seamus Heaney ◽  
Irish Society ◽  
Irish Context ◽  
Key Points ◽  
The Many ◽  
The Impact ◽  
The Relationship

In this article I examine aspects of the relationship between mothers and sons from an attachment perspective in an Irish context. Through the works of Irish writers such as Seamus Heaney, John McGahern, and Colm Tóibín, I focus on particular aspects of this relationship, which fails to support the developmental processes of separation and individuation in the many men who come to me for psychotherapy. I illustrate key points concerning this attachment dynamic through the use of clinical examples of my work with two men from my practice. While acknowledging that many other cultural factors play a significant role in the emotional development of children, integrating the work of our poets, novelists, and scholars with an attachment perspective

The unknown acquaintance, or the impact factor and others

2007 ◽  
Vol 148 (4) ◽  
pp. 165-171
Author(s):  
Anna Berhidi ◽  
Edit Csajbók ◽  
Lívia Vasas
Keyword(s):  
Impact Factor ◽  
Citation Analysis ◽  
Index Number ◽  
Scientific Performance ◽  
H Index ◽  
Master List ◽  
The Many ◽  
The Impact

Nobody doubts the importance of the scientific performance’s evaluation. At the same time its way divides the group of experts. The present study mostly deals with the models of citation-analysis based evaluation. The aim of the authors is to present the background of the best known tool – Impact factor – since, according to the authors’ experience, to the many people use without knowing it well. In addition to the „nonofficial impact factor” and Euro-factor, the most promising index-number, h-index is presented. Finally new initiation – Index Copernicus Master List – is delineated, which is suitable to rank journals. Studying different indexes the authors make a proposal and complete the method of long standing for the evaluation of scientific performance.

Surveying adherence of dental clinic patients to preventive measures in oral cavity

2019 ◽  
Vol 24 (2) ◽  
pp. 167-172 ◽  
Author(s):  
T. V. Kudryavtseva ◽  
V. V. Tachalov ◽  
E. S. Loboda ◽  
L. Yu. Orekhova ◽  
E. Yu. Nechai ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Working Conditions ◽  
Oral Hygiene ◽  
Preventive Measures ◽  
Periodontal Diseases ◽  
Dental Health ◽  
Developed Countries ◽  
Dental Clinic ◽  
The Many ◽  
The Impact

Relevance. Periodontal diseases are a medical and social problem due to the wide spread among the population of developed countries and the impact on the quality of life. Among the many factors that are important in the development of inflammatory periodontal diseases, an important role is played by adherence to the recommendations of the dentist in respecting oral hygiene. Aim of the work was to study the adherence of patients of the dental clinic to compliance with preventive measures in the oral cavity.Materials and methods. A total of 98 patients of dental clinic, 62 female (medial age 38,6 ± 14,0 years) and 36 male (medial age 37,2±13,1 years) participated in survey. The study participants flled in the profle and answered questions about age, gender, harmful working conditions and bad habits, frequency of visits to the dental clinic, attitudes to the prevention of dental diseases, knowledge about the means and methods of oral hygiene.Results. As a result of the study, it was found that in the vast majority of cases, respondents are employed in production that does not adversely affect their health (91%), only 8% of patients indicated harmful working conditions.Conclusions. The study revealed that, despite the recommendations of the dentist, patients are not always committed to the implementation of preventive measures in the oral cavity. Dentists need to motivate patients to use not only the usual methods and means of hygiene, but also additional ones necessary for maintaining dental health.

Performance Analysis of RNC Clustering Protocol in Wireless Sensor Network

2019 ◽  
Vol 10 ◽  
Author(s):  
Piyush Rawat ◽  
Siddhartha Chauhan
Keyword(s):  
Energy Consumption ◽  
Network Performance ◽  
Energy Levels ◽  
Cluster Head ◽  
Base Station ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Threshold Function ◽  
Efficient Manner ◽  
Clustering Protocol

Background and Objective: The functionalities of wireless sensor networks (WSN) are growing in various areas, so to handle the energy consumption of network in an efficient manner is a challenging task. The sensor nodes in the WSN are equipped with limited battery power, so there is a need to utilize the sensor power in an efficient way. The clustering of nodes in the network is one of the ways to handle the limited energy of nodes to enhance the lifetime of the network for its longer working without failure. Methods: The proposed approach is based on forming a cluster of various sensor nodes and then selecting a sensor as cluster head (CH). The heterogeneous sensor nodes are used in the proposed approach in which sensors are provided with different energy levels. The selection of an efficient node as CH can help in enhancing the network lifetime. The threshold function and random function are used for selecting the cluster head among various sensors for selecting the efficient node as CH. Various performance parameters such as network lifespan, packets transferred to the base station (BS) and energy consumption are used to perform the comparison between the proposed technique and previous approaches. Results and Discussion: To validate the working of the proposed technique the simulation is performed in MATLAB simulator. The proposed approach has enhanced the lifetime of the network as compared to the existing approaches. The proposed algorithm is compared with various existing techniques to measure its performance and effectiveness. The sensor nodes are randomly deployed in a 100m*100m area. Conclusion: The simulation results showed that the proposed technique has enhanced the lifespan of the network by utilizing the node’s energy in an efficient manner and reduced the consumption of energy for better network performance.

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