Simplest Flow Queuing Models for LEO Satellite System

2022 ◽  
pp. 61-70
Author(s):  
S.B. Pichugin
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Satellite System ◽  
Low Earth Orbit ◽  
Analytical Models ◽  
Mathematical Apparatus ◽  
Satellite Systems ◽  
Ground Station ◽  
Queuing Models ◽  
Leo Satellite

The relevance of the work is associated with the active deployment of low-orbit communication systems and the expansion of research in the field of corresponding satellite systems. A promising low-orbit communication system based on relay satellites with the function (RSRFs) of routing message packets is considered. The low earth orbit communications systems use the BGP protocol and the AAA functionality at the ground station. For assessing the characteristics of RSRF inter-satellite paths, a scenario was created for the message packets arrival from a group of inter-satellite paths to one subscriber path. The corresponding analytical models have been developed using the mathematical apparatus of queuing systems with the simplest flows of requests and exponential distribution of the service time. The RSRF characteristics of a promising low-orbit communication system are predicted. It is proposed to make the mathematical apparatus of analytical models more complicated to take into account the dynamics of displacements and failures of the RSRF in a low-orbit communication system.

scholarly journals On the Security of LEO Satellite Communication Systems: Vulnerabilities, Countermeasures, and Future Trends

2022 ◽  
Author(s):  
Pingyue Yue ◽  
Jianping An ◽  
Jiankang Zhang ◽  
Gaofeng Pan ◽  
Shuai Wang ◽  
...  
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Satellite Communication ◽  
Future Trends ◽  
Comprehensive Review ◽  
Satellite Communication System ◽  
Development Status ◽  
System A ◽  
Leo Satellite

<div>In view of the development status of the security of LEO satellite communication system, a comprehensive review, induction, and summary is carried out.<br></div>

scholarly journals Satellite Availability and Service Performance Evaluation for Next-Generation GNSS, RNSS and LEO Augmentation Constellation

2021 ◽  
Vol 13 (18) ◽  
pp. 3698
Author(s):  
Haomeng Cui ◽  
Shoujian Zhang
Keyword(s):  
Satellite System ◽  
Low Earth Orbit ◽  
Global Navigation Satellite Systems ◽  
Navigation Satellite ◽  
Next Generation ◽  
Satellite Systems ◽  
Satellite Visibility ◽  
Under Construction ◽  
Global Navigation Satellite ◽  
Average Position

Positioning accuracy is affected by the combined effect of user range errors and the geometric distribution of satellites. Dilution of precision (DOP) is defined as the geometric strength of visible satellites. DOP is calculated based on the satellite broadcast or precise ephemerides. However, because the modernization program of next-generation navigation satellite systems is still under construction, there is a lack of real ephemerides to assess the performance of next-generation constellations. Without requiring real ephemerides, we describe a method to estimate satellite visibility and DOP. The improvement of four next-generation Global Navigation Satellite Systems (four-GNSS-NG), compared to the navigation constellations that are currently in operation (four-GNSS), is statistically analyzed. The augmentation of the full constellation the Quasi-Zenith Satellite System (7-QZSS) and the Navigation with Indian Constellation (11-NavIC) for regional users and the low Earth orbit (LEO) constellation enhancing four-GNSS performance are also analyzed based on this method. The results indicate that the average number visible satellites of the four-GNSS-NG will reach 44.86, and the average geometry DOP (GDOP) will be 1.19, which is an improvement of 17.3% and 7.8%, respectively. With the augmentation of the 120-satellite mixed-orbit LEO constellation, the multi-GNSS visible satellites will increase by 5 to 8 at all latitudes, while the GDOP will be reduced by 6.2% on average. Adding 7-QZSS and 11-NavIC to the four-GNSS-NG, 37.51 to 71.58 satellites are available on global scales. The average position DOP (PDOP), horizontal DOP (HDOP), vertical DOP (VDOP), and time DOP (TDOP) are reduced to 0.82, 0.46, 0.67 and 0.44, respectively.

Overview on Physical Layer Security in Low Earth Orbit (LEO) Satellite System

2021 ◽  
Author(s):  
Cheng-Ying Yang ◽  
Jenq-Foung JF Yao ◽  
Chin-En Yen ◽  
Min-Shiang Hwang
Keyword(s):  
Physical Layer Security ◽  
Satellite System ◽  
Physical Layer ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Leo Satellite

SUPPORTING DISTRESS SIGNALS OVER LOW EARTH ORBIT MOBILE SATELLITE SYSTEMS FOR EMERGENCY INFORMATION ACQUISITION

2013 ◽  
Vol 09 (03n04) ◽  
pp. 1350018
Author(s):  
GAMAL A. HUSSEIN ◽  
MOSTAFA A. NOFAL ◽  
MOAWAD I. DESSOUKY ◽  
OSAMA ALY ORABY ◽  
WALEED AL-HANAFY ◽  
...  
Keyword(s):  
Information Acquisition ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Rescue Operation ◽  
Satellite Systems ◽  
Leo Satellites ◽  
Mobile Satellite ◽  
Voice Data ◽  
Leo Satellite ◽  
Service Priority

Low earth orbit (LEO) satellite systems allow a broad range of services to be provided using small, lightweight, cellular-like portable telephones. Exploiting LEO satellites to support distress signals for aircrafts, ships and international travelers is explored in the current paper. A multi-service priority-oriented algorithm is proposed for handling voice, data and emergency signals over LEO satellites. The emergency signal is privileged with service priority so that rescue operation can be carried out as soon as possible. The priority mechanism includes channel reservation as well as joining a queue if no free channel is available as long as the request is roaming in the handover area. In addition, a simplified but efficient approach is suggested for locating the object of an imminent danger situation. As LEO satellites are non-geostationary, the visible period of each spot-beam is small. Consequently, a teletraffic model, that accommodates the mobility of spot-beams as well as the resulting handover rate, is developed in order to gauge the performance of the proposed algorithm. Numerical results for access denying and service-dropping rates are presented for nominal system parameters.

scholarly journals Integration of satellite system and Stratospheric Communication Platforms (SCP) for weather observation

2016 ◽  
Author(s):  
◽  
Sihle S. Sibiya
Keyword(s):  
High Altitude ◽  
Communication Systems ◽  
Satellite Communication ◽  
Meteorological Data ◽  
Cost Effective ◽  
Satellite System ◽  
Satellite Systems ◽  
Observation Area ◽  
Solar Powered ◽  
Weather Observation

This doctoral research introduces an integration of satellite systems and new stratospheric platforms for weather observation, imaging and transfer of meteorological data to the ground infrastructures. Terrestrial configuration and satellite communication subsystems represent well-established technologies that have been involved in global satellite sensing and weather observation area for years. However, in recent times, a new alternative has emerged based on quasi-stationary aerial platforms located in the Stratosphere called High Altitude Platform (HAP) or Stratospheric Communication Platforms (SCP). The SCP systems seem to represent a dream come true for communication engineers since they preserve most of the advantages of both terrestrial and satellite communication systems. Today, SCP systems are able to help, in a more cost effective way, developments of space Earth sensing and weather observation and weather sensing and observation. This new system can provide a number of forms ranging from a low altitude tethered balloon to a high altitude (18 – 25 km) fuel-powered piloted aircraft, solar-powered unmanned airplanes and solar-powered airship.

scholarly journals Forecasting Methods of Battery Charge and Discharge Current Profile for LEO Satellites

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2999
Author(s):  
Seok-Teak Yun ◽  
Seung-Hyun Kong
Keyword(s):  
Discharge Current ◽  
Short Term Memory ◽  
Low Earth Orbit ◽  
Mission Design ◽  
Access Time ◽  
Current Profile ◽  
Satellite Systems ◽  
Battery Charge ◽  
Leo Satellites ◽  
Leo Satellite

The orbital characteristics of low Earth orbit (LEO) satellite systems prevent continuous monitoring because ground access time is limited. For this reason, the development of simulators for predicting satellite states for the entire orbit is required. Power-related prediction is one of the important LEO satellite simulations because it is directly related to the lifespan and mission of the satellite. Accurate predictions of the charge and discharge current of a power system’s battery are essential for fault management design, mission design, and expansion of LEO satellites. However, it is difficult to accurately predict the battery power demand and charging of LEO satellites because they have nonlinear characteristics that depend on the satellite’s attitude, season, orbit, mission, and operating period. Therefore, this paper proposes a novel battery charge and discharge current prediction technique using the bidirectional long short-term memory (Bi-LSTM) model for the development of a LEO satellite power simulator. The prediction performance is demonstrated by applying the proposed technique to the KOM-SAT-3A and KOMSAT-5 satellites operating in real orbits. As a result, the prediction accuracy of the proposed Bi-LSTM shows root mean square error (RMSE) within 2.3 A, and the prediction error well outperforms the most recent the probability-based SARIMA model.

Automated Ground Station Design for an Amateur LEO Satellite System

2019 ◽  
Author(s):  
Lipika Garg ◽  
Atharva Kand ◽  
Malhar Pradhan ◽  
Abhishek Agarwal
Keyword(s):  
Satellite System ◽  
Ground Station ◽  
Leo Satellite

scholarly journals Rain Attenuation Prediction Models in Microwave and Millimeter Bands for Satellite Communication System: A Review

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Hammed O Busari ◽  
Olaosebikan A Fakolujo
Keyword(s):  
Frequency Band ◽  
Communication System ◽  
Communication Systems ◽  
Satellite Communication ◽  
Rain Rate ◽  
Satellite System ◽  
Rain Attenuation ◽  
Rapid Expansion ◽  
Satellite Communication System ◽  
Communication Signal

The progressively demand on satellite communication systems has consequently resulted in lower frequency bands getting more congested. The usage of frequency band beyond 10 GHz is in focus nowadays as a result of the rapid expansion of radio communication systems. However, Rain is the leading attenuation factor of different communication signal of frequencies beyond 10 GHz. Attenuation due to rain has a significant propagation effect that needs to be carefully considered in satellite communication system network. Rain attenuation predictions and rain rate are essential when planning microwave satellite communication links.  A review of the rain rate integration time and rain attenuation models for microwave and millimeter bands satellite system is presented.  Keywords: Frequency Band, Rain Attenuation, Rain Attenuation Model, Rain Rate, Satellite System

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