Simulation analysis of a method to improve data-transmission performance of Nanshan 26m Radio Telescope based on Software-Defined Networks

2021 ◽  
Vol 21 (11) ◽  
pp. 279
Author(s):  
Jie Wang ◽  
Hai-Long Zhang ◽  
Na Wang ◽  
Xin-Chen Ye ◽  
Wan-Qiong Wang ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Data Transmission ◽  
Network Architecture ◽  
High Speed ◽  
Astronomical Observation ◽  
Observation Data ◽  
Software Defined Networks ◽  
Continuous Increase ◽  
Network Bandwidth ◽  
Tcp Throughput

Abstract Data Center of Xinjiang Astronomical Observatory (XAO-DC) commenced operating in 2015, and provides services including archiving, releasing and retrieving precious astronomical data collected by the Nanshan 26m Radio Telescope (NSRT) over the years, and realises the open sharing of astronomical observation data. The observation data from NSRT are transmitted to XAO-DC 100 km away through dedicated fiber for long-term storage. With the continuous increase of data, the static architecture of the current network cannot meet NSRT data-transmission requirements due to limited network bandwidth. To get high-speed data-transmission using the existing static network architecture, a method for reconstruction data-transmission network using Software-Defined Networks (SDN) is proposed. Benefit from the SDNʼs data and control plane separation, and open programmable, combined with the Mininet simulation platform for experiments, the TCP throughput (of single thread) was improved by ∼24.7%, the TCP throughput (of multi threads) was improved by ∼9.8%, ∼40.9%, ∼35.5% and ∼11.7%. Compared with the current network architecture, the Latency was reduced by ∼63.2%.

High-Speed Tension Tests at Elevated Temperatures—Parts II and III

1941 ◽  
Vol 8 (2) ◽  
pp. A77-A91
Author(s):  
A. Nadai ◽  
M. J. Manjoine
Keyword(s):  
Strain Rate ◽  
Pure Iron ◽  
High Speed ◽  
Elevated Temperatures ◽  
Testing Machine ◽  
Constant Strain Rate ◽  
Observation Data ◽  
Continuous Increase ◽  
Wide Range ◽  
Plastic Forming

Abstract The authors discuss the results of an investigation on the resistance to plastic forming of several metals over a wide range of rates of deformation at various temperatures. To carry out the tests, two machines were built: One, a high-speed testing machine, was described in Part I of this report; the other, a constant-strain-rate machine, is dealt with in this presentation. The general trend of the test results for aluminum and copper indicates a continuous increase of the yield stresses with the strain rate. The speed relation for pure iron and the iron alloys seems to be much more complicated. The resistance to deformation at a given speed of straining exhibits a minimum and a maximum at certain temperatures. This maximum, known as “blue brittleness,” shifts to higher temperatures with increasing speeds of straining; it appears at 200 C for short-time tension speeds and shifts to 550 C for the high speeds. In the high-speed tests a local temperature rise of 50 C, due to the conversion of the work of deformation into heat, was observed in a specimen of pure iron. At very rapid rates of deformation remarkably high ultimate stresses were found for aluminum and copper when tested at temperatures approaching their melting points. A theory for the necking of a bar, based on the speed law, predicts the observed shapes of broken bars which were drawn down to a point. Observation data are furnished for an evaluation of the forces required for very rapid plastic forming of the metals at high temperatures, particularly through rolling.

Research of Multimedia Data Transmission Based on UDP

2010 ◽  
Vol 129-131 ◽  
pp. 1291-1295
Author(s):  
Xiao Qiang Jiang
Keyword(s):  
Data Transmission ◽  
Reliable Data ◽  
Video Data ◽  
Multimedia Data ◽  
Transmission Protocol ◽  
Continuous Increase ◽  
Data Network ◽  
Network Bandwidth ◽  
Network Transmission ◽  
Multimedia Data Transmission

The article focuses on the research of a reliable data transmission extension protocol -- UDT based on UDP, the related implementation method and transmission control method of multimedia data real-time and reliable transmission, the improvement to algorithm of its related methods in specific applications; as well as the improvement to AIMD (Additive Increase and Multiplicative Decrease) congestion controlling algorithm, proposing DAIMD congestion controlling algorithm; the sending rate increment is changed from the constant quantity to the variable quantity which continuously reduces with the continuous increase of the sending rates, so it not only makes a more rational use of limited network bandwidth, also reduces the larger oscillation in the network data transmission; the improvement of validation mechanisms, propose validation mechanisms based on the combination of time and data packets numbers, and improve the efficiency of data transmission. When the multimedia data network transmits, the transmitter and receiver need to identify a network transmission protocol. According to the above analysis, UDP is a simple transmission level protocol, non-connection-oriented, and itself does not provide data retransmission and confirmation, therefore adopting UDP as the network transmission protocol can improve the data transmission efficiency, besides UDP supports the webcast function, suitable for multimedia data network transmission [1]. However, the characteristic of multimedia data network transmission requests the network transmission protocol can handle the phenomenon of delay and vibration in the transmission process; can handle bursting multimedia data transmission; can judge the network condition according to the reception quality of the receiver and the sender can make the appropriate response; can ensure the reliability of multimedia data network transmission and so on. Features of UDP its own design make it deal with such situations not very well, also UDP limits the sending data packet size each time; when the multimedia data network transmits, a video data often exceed this limit. Therefore, according to the previous analysis of multimedia data network transmission characteristics and technical requirements, this article studies the reliable data transmission extension protocol -- UDT based on UDP, and improves the related algorithm and control mechanism in the protocol to make it more suitable for the multimedia data network transmission in the embedded video surveillance system.

Analysis of Inter-Satellite Optical Wireless Communication System

2017 ◽  
Vol 7 (10) ◽  
pp. 10
Author(s):  
Rajbir Singh
Keyword(s):  
Wireless Communication ◽  
Optical Networks ◽  
Data Transmission ◽  
High Speed ◽  
Open Space ◽  
Communication Link ◽  
Optical Wireless Communication ◽  
Optical Wireless ◽  
High Speed Data ◽  
Speed Data Transmission

Optical networks are bandwidth efficient networks are used for long haul communication providing seamless data transfer. For high speed data transmission in open space between different satellites, Inter-satellite Optical wireless communication (IsOWC) is widely used .In this paper we have evaluated the performance of IsOWC communication link for high speed data transmission .The performance of the system is evaluated on the basis of qualitative parameters such as Q-factor and BER using optisystem simulator.

Top-down Fabricated Gold Nanostrip on Silicon-on-insulator Wafer: A Promising Building Block towards Ultra-compact Optical Device

Nanoscale ◽  
2020 ◽  
Author(s):  
Fuping Zhang ◽  
Weikang Liu ◽  
Li Chen ◽  
Zhiqiang Guan ◽  
Hongxing Xu
Keyword(s):  
Optical Communication ◽  
Data Transmission ◽  
Building Block ◽  
High Speed ◽  
Large Data ◽  
Low Energy ◽  
Silicon On Insulator ◽  
Fundamental Building Block ◽  
Low Energy Consumption ◽  
Controllable Fabrication

he plasmonic waveguide is the fundamental building block for high speed, large data transmission capacity, low energy consumption optical communication and sensing. Controllable fabrication and simultaneously optimization of the propagation...

scholarly journals A 1.55-to-32-Gb/s Four-Lane Transmitter with 3-Tap Feed Forward Equalizer and Shared PLL in 28-nm CMOS

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 1873
Author(s):  
Chen Cai ◽  
Xuqiang Zheng ◽  
Yong Chen ◽  
Danyu Wu ◽  
Jian Luan ◽  
...  
Keyword(s):  
Data Transmission ◽  
High Speed ◽  
Data Rate ◽  
Quality Data ◽  
Cmos Process ◽  
Voltage Controlled Oscillator ◽  
Feed Forward ◽  
Fully Integrated ◽  
Output Driver ◽  
28 Nm

This paper presents a fully integrated physical layer (PHY) transmitter (TX) suiting for multiple industrial protocols and compatible with different protocol versions. Targeting a wide operating range, the LC-based phase-locked loop (PLL) with a dual voltage-controlled oscillator (VCO) was integrated to provide the low jitter clock. Each lane with a configurable serialization scheme was adapted to adjust the data rate flexibly. To achieve high-speed data transmission, several bandwidth-extended techniques were introduced, and an optimized output driver with a 3-tap feed-forward equalizer (FFE) was proposed to accomplish high-quality data transmission and equalization. The TX prototype was fabricated in a 28-nm CMOS process, and a single-lane TX only occupied an active area of 0.048 mm2. The shared PLL and clock distribution circuits occupied an area of 0.54 mm2. The proposed PLL can support a tuning range that covers 6.2 to 16 GHz. Each lane's data rate ranged from 1.55 to 32 Gb/s, and the energy efficiency is 1.89 pJ/bit/lane at a 32-Gb/s data rate and can tune an equalization up to 10 dB.

A Dicode Signaling Scheme for Capacitively Coupled Interface

2011 ◽  
Vol 497 ◽  
pp. 296-305
Author(s):  
Yasushi Yuminaka ◽  
Kyohei Kawano
Keyword(s):  
Partial Response ◽  
Data Transmission ◽  
High Speed ◽  
Circuit Simulation ◽  
Frequency Bandwidth ◽  
Capacitively Coupled ◽  
Limited Frequency ◽  
Simulation Results ◽  
Response Coding ◽  
The Impact

In this paper, we present a bandwidth-efficient partial-response signaling scheme for capacitivelycoupled chip-to-chip data transmission to increase data rate. Partial-response coding is knownas a technique that allows high-speed transmission while using a limited frequency bandwidth, by allowingcontrolled intersymbol interference (ISI). Analysis and circuit simulation results are presentedto show the impact of duobinary (1+D) and dicode (1-D) partial-response signaling for capacitivelycoupled interface.

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