scholarly journals Research on Virtual Channel Multiplexing Algorithm Based on Advanced Orbiting Systems

IEEE Access ◽  
2018 ◽  
Vol 6 ◽  
pp. 70843-70853
Author(s):  
Yuxia Bie ◽  
Ye Tian ◽  
Zhi Hu ◽  
Yueqiu Jiang
Author(s):  
Eddy Luis Molina Morales ◽  
Oscar Emilio Rodriguez Ramirez ◽  
Leandro De Haro Arriet

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Ye Tian ◽  
Qingfan Li ◽  
Yongxin Feng ◽  
Xiaoling Gao

A virtual channels scheduling algorithm with broad applicability based on movable boundary is proposed. According to the types of date sources, transmission time slots are divided into synchronous ones and asynchronous ones with a movable boundary between them. During the synchronous time slots, the virtual channels are scheduled with a polling algorithm; during the asynchronous time slots, the virtual channels are scheduled with an algorithm based on virtual channel urgency and frame urgency. If there are no valid frames in the corresponding VC at a certain synchronous time slot, a frame of the other synchronous VCs or asynchronous VCs will be transmitted through the physical channel. Only when there are no valid frames in all VCs would an idle frame be generated and transmitted. Experiments show that the proposed algorithm yields much lower scheduling delay and higher channel utilization ratio than those based on unmovable boundary or virtual channel urgency in many kinds of sources. Therefore, broad applicability can be achieved by the proposed algorithm.


2008 ◽  
Vol 29 (2) ◽  
pp. 250-260 ◽  
Author(s):  
Carlo K. Berenstein ◽  
Lucas H. M. Mens ◽  
Jef J. S. Mulder ◽  
Filiep J. Vanpoucke

2021 ◽  
Vol 11 (18) ◽  
pp. 8632
Author(s):  
Andrea Delfini ◽  
Roberto Pastore ◽  
Fabrizio Piergentili ◽  
Fabio Santoni ◽  
Mario Marchetti

The increasing number of satellites orbiting around Earth has led to an uncontrolled increase in objects within the orbital environment. Since the beginning of the space age on 4 October 1957 (launch of Sputnik I), there have been more than 4900 space launches, leading to over 18,000 satellites and ground-trackable objects currently orbiting the Earth. For each satellite launched, several other objects are also sent into orbit, including rocket upper stages, instrument covers, and so on. Having a reliable system for tracking objects and satellites and monitoring their attitude is at present a mandatory challenge in order to prevent dangerous collisions and an increase in space debris. In this paper, the evaluation of the reflection coefficient of different shaped objects has been carried out by means of the bi-static reflection method, also known as NRL arch measurement, in order to evaluate their visibility and attitude in a wide range of frequencies (12–18 GHz). The test campaign aims to correlate the experimental measures with the hypothetical reflection properties of orbiting systems.


Sign in / Sign up

Export Citation Format

Share Document