scholarly journals Correction: Ortiz-Gomez, F.G. et al. Forward Link Optimization for the Design of VHTS Satellite Networks. Electronics 2020, 9, 473

Electronics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 737
Author(s):  
Flor G. Ortiz-Gomez ◽  
Ramón Martínez ◽  
Miguel A. Salas-Natera ◽  
Andrés Cornejo ◽  
Salvador Landeros-Ayala
Keyword(s):  
Satellite Networks ◽  
Forward Link ◽  
Published Paper

We, the authors, wish to make the following correction to our published paper [...]

scholarly journals Forward Link Optimization for the Design of VHTS Satellite Networks

Electronics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 473 ◽  
Author(s):  
Flor G. Ortiz-Gomez ◽  
Ramón Martínez ◽  
Miguel A. Salas-Natera ◽  
Andrés Cornejo ◽  
Salvador Landeros-Ayala
Keyword(s):  
Cost Model ◽  
High Capacity ◽  
Optimal Solution ◽  
Satellite Networks ◽  
Forward Link ◽  
User Terminal ◽  
Trade Offs ◽  
Service Areas ◽  
Optimum Solution ◽  
The Cost

The concept of geostationary VHTS (Very High Throughput Satellites) is based on multibeam coverage with intensive frequency and polarization reuse, in addition to the use of larger bandwidths in the feeder links, in order to provide high capacity satellite links at a reduced cost per Gbps in orbit. The dimensioning and design of satellite networks based on VHTS imposes the analysis of multiple trade-offs to achieve an optimal solution in terms of cost, capacity, and the figure of merit of the user terminal. In this paper, we propose a new method for sizing VHTS satellite networks based on an analytical expression of the forward link CINR (Carrier-to-Interference-plus-Noise Ratio) that is used to evaluate the trade-off of different combinations of system parameters. The proposed method considers both technical and commercial requirements as inputs, including the constraints to achieve the optimum solution in terms of the user G/T, the number of beams, and the system cost. The cost model includes both satellite and ground segments. Exemplary results are presented with feeder links using Q/V bands, DVB-S2X and transmission methods based on CCM and VCM (Constant and Variable Coding and Modulation, respectively) in two scenarios with different service areas.

scholarly journals Forward Link Optimization for the Design of VHTS Satellite Networks

2020 ◽  
Author(s):  
Flor G. Ortiz-Gomez ◽  
Ramón Martínez ◽  
Miguel A. Salas-Natera ◽  
Andrés Cornejo ◽  
Salvador Landeros-Ayala
Keyword(s):  
Cost Model ◽  
High Capacity ◽  
Optimal Solution ◽  
Satellite Networks ◽  
Forward Link ◽  
User Terminal ◽  
Trade Offs ◽  
Service Areas ◽  
Optimum Solution ◽  
The Cost

The concept of geostationary VHTS (Very High Throughput Satellites) is based on multibeam coverage with intensive frequency and polarization reuse in addition to the use of larger bandwidths in the feeder links, in order to provide high capacity satellite links at a reduced cost per Gbps in orbit. The dimensioning and design of satellite networks based on VHTS imposes the analysis of multiple trade-offs to achieve an optimal solution in terms of cost, capacity and figure of merit of the user terminal. In this paper, we propose a new method for sizing VHTS satellite networks based on an analytical expression of the forward link CINR (Carrier-to-Interference-plus-Noise Ratio) that is used to evaluate the trade-off of different combinations of system parameters. The proposed method considers both technical and commercial requirements as inputs including the constraints to achieve the optimum solution in terms of the user G/T, the number of beams and the system cost. The cost model includes both satellite and ground segments. Exemplary results are presented with feeder links using Q/V bands, DVB-S2X and transmission methods based on CCM and VCM (Constant and Variable Coding and Modulation, respectively) in two scenarios with different service areas.

Rollback Links Characterization for the Snapshot Routing Algorithm in Polar-Orbit Satellite Networks

2015 ◽  
Vol E98.B (8) ◽  
pp. 1715-1724 ◽  
Author(s):  
Zhu TANG ◽  
Chunqing WU ◽  
Zhenqian FENG ◽  
Wanrong YU ◽  
Baokang ZHAO ◽  
...  
Keyword(s):  
Routing Algorithm ◽  
Satellite Networks ◽  
Polar Orbit ◽  
Orbit Satellite

Enhanced TCP westwood algorithm-based on loss differentiation over GEO satellite networks

2009 ◽  
Vol 28 (11) ◽  
pp. 2763-2766
Author(s):  
Jian-feng WANG ◽  
Guo-ce HUANG ◽  
Qiao-yan KANG
Keyword(s):  
Satellite Networks ◽  
Geo Satellite ◽  
Tcp Westwood ◽  
Loss Differentiation

Coordinated Hyperspectral Imaging Nano-Satellite Networks for Space Situational Awareness

2011 ◽  
Author(s):  
John McInroy ◽  
Suresh Muknahallipatna ◽  
Margareta Stefanovic ◽  
Farhad Jafari
Keyword(s):  
Hyperspectral Imaging ◽  
Situational Awareness ◽  
Satellite Networks ◽  
Space Situational Awareness

Driver’s Drowsiness Detection Using Dlib and IOT

2020 ◽  
Vol 10 ◽  
Author(s):  
Prasanna Lakshmi Kompalli ◽  
Padma Vallakati ◽  
Ganapathi Raju Nadimpalli ◽  
Vinod Mahesh Jain ◽  
Samuel Annepogu
Keyword(s):  
Aspect Ratio ◽  
The Other ◽  
Human Intervention ◽  
Road Accidents ◽  
Online Content ◽  
Facial Landmarks ◽  
Drowsiness Detection ◽  
Rear Part ◽  
Cause Of Deaths ◽  
Published Paper

Background: Road accidents are major cause of deaths worldwide. This is enormously due to fatigue, drowsiness and microsleep of the drivers. This don’t just risk the life of driver and copassengers but also a great threat to the vehicles and humans moving around that vehicle. Methods: Research, online content and previously published paper related to drowsiness are reviewed. Using the facial landmarks DAT file, the prototype will locate and get the eye coordinates and it will calculate Eye Aspect Ratio (EAR). The EAR indicates whether the driver is drowsy or not based on the result various sensors gets activated such as Alarm generator, LED Indicators, LCD message scroll, message sent to owner and engine gets locked. Results: The prototype is able to locate eyes in the frame and detect whether the person is sleepy or not. Whenever the person is feeling drowsy alarm gets generated in the cabinet on further if the person is feeling drowsy, LED indicators will start glowing, messaging will be scrolling at the rear part of vehicle so that other vehicles and humans gets cautioned and vehicle slows down and engine gets locked. Conclusion: This prototype will help in reduction of road accidents due to human intervention. It is not only helpful to the person who install it in their vehicles but also for the other vehicles and humans moving around it.

The impact of duration observations on precision of results GNSS measurements

2017 ◽  
Vol 921 (3) ◽  
pp. 7-13 ◽  
Author(s):  
S.V. Grishko
Keyword(s):  
Measurement Accuracy ◽  
Functional Dependence ◽  
Observation Time ◽  
Satellite Networks ◽  
Satellite Measurements ◽  
Proposed Model ◽  
Actual Error ◽  
Gnss Measurements ◽  
The Impact ◽  
Qualitative Characteristics

This paper shows that the accuracy of relative satellite measurements depend not only on the length of the baseline, as it is regulated by the rating formula of accuracy of GNSS equipment, but also on the duration of observations. As a result of the strict adjustment much redundant satellite networks with different duration of observations obtained covariance matrix of baselines, the most realistic reflecting the actual error of satellite observations. Research of forms of communication of these errors from length of the baseline and duration of its measurement is executed. A significant influence of solar activity on accuracy of satellite measurements, in general, leads to unequal similar series of measurements made at different periods, for example, in the production of monitoring activities. The model of approximation of the functional dependence of accuracy of the baseline from its length and duration of observations having good qualitative characteristics is offered. Based on the proposed model, we analyzed the dynamics of changes in measurement accuracy with an increase in observation time.

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