Sky Station Stratospheric Telecommunications System, a high speed low latency switched wireless network

1998 ◽  
Author(s):  
Yee-Chun Lee ◽  
Huanchun Ye
Keyword(s):  
Wireless Network ◽  
High Speed ◽  
Low Latency ◽  
System A

scholarly journals Comprehensive Analysis on Heterogeneous Wireless Network in High-Speed Scenarios

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yuyang Zhang ◽  
Tao Zheng ◽  
Ping Dong ◽  
Hongbin Luo ◽  
Zhibo Pang
Keyword(s):  
Wireless Network ◽  
Heterogeneous Network ◽  
High Speed ◽  
Schedule Algorithm ◽  
Good Choice ◽  
Comprehensive Analysis ◽  
Low Latency ◽  
High Bandwidth ◽  
Network Quality ◽  
Stable Network

Greater demands are being placed on the access bandwidth, stability, and delay of network because of the quickening rhythm of life and work, especially in mobile scenario. In order to obtain a stable network with low latency and high bandwidth in mobile scenario, taking advantage of the wireless heterogeneous network in parallel is a good choice. Nowadays, people are increasingly concerned about the network quality under the mobile scenario. Some scholars have done the relevant measurements. However, all of those measurements mainly investigate part of the network parameters or part of mobile scenarios. In this paper, we make the following contributions. Firstly, in high-speed mobile scenario, the wireless network qualities of different vendors are measured synthetically. Secondly, we analyze the benefits of taking advantage of the different vendors. Thirdly, we deploy the replication link mechanism in high-speed mobile scenario and propose an algorithm to remove the duplicate packet in high-speed mobile scenario. And the algorithm can also be used in another multipath schedule algorithm to improve the reliability.

The Study on the Framework of Wireless Network System

2010 ◽  
Vol 20-23 ◽  
pp. 814-819
Author(s):  
Xue Qing Ji
Keyword(s):  
Wireless Network ◽  
High Speed ◽  
Fresnel Lens ◽  
Network System ◽  
Lens System ◽  
System Framework ◽  
Analogue Simulation ◽  
System A ◽  
New Type

From several basic frameworks wireless network system, a new type of system framework was designed. Its conformation of optics system and achievement by module were described particularly through using Fresnel lens system. This system’s link could be transformed between directed LOS link and non-directed LOS link, which made the system communicate at a high-speed when there were no barriers between the emitter and receiver and keep a good convexity when barriers appeared. At last what should be noted for the analogue simulation was brought up.

scholarly journals Development of a High-Speed, Low-Latency Telemanipulated Robot Hand System

Robotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 41
Author(s):  
Yuji Yamakawa ◽  
Yugo Katsuki ◽  
Yoshihiro Watanabe ◽  
Masatoshi Ishikawa
Keyword(s):  
High Speed ◽  
Vision System ◽  
Low Latency ◽  
Human Hand ◽  
Robot Hand ◽  
Hand Motion ◽  
Visual Sensing ◽  
System A ◽  
Robot Hands ◽  
3D Sensing

This paper focuses on development of a high-speed, low-latency telemanipulated robot hand system, evaluation of the system, and demonstration of the system. The characteristics of the developed system are the followings: non-contact, high-speed 3D visual sensing of the human hand, intuitive motion mapping between human hands and robot hands, and low-latency, fast responsiveness to human hand motion. Such a high-speed, low-latency telemanipulated robot hand system can be considered to be more effective from the viewpoint of usability. The developed system consists of a high-speed vision system, a high-speed robot hand, and a real-time controller. For the developed system, we propose new methods of 3D sensing, mapping between the human hand and the robot hand, and the robot hand control. We evaluated the performance (latency and responsiveness) of the developed system. As a result, the latency of the developed system is so small that humans cannot recognize the latency. In addition, we conducted experiments of opening/closing motion, object grasping, and moving object grasping as demonstrations. Finally, we confirmed the validity and effectiveness of the developed system and proposed method.

An overview of the 5G mobile network architecture

2018 ◽  
Author(s):  
Phanidra Palagummi ◽  
Vedant Somani ◽  
Krishna M. Sivalingam ◽  
Balaji Venkat
Keyword(s):  
Wireless Network ◽  
Mobile Networks ◽  
Network Architecture ◽  
Mobile Network ◽  
Communication Technologies ◽  
Future Generation ◽  
Network Function Virtualization ◽  
Low Latency ◽  
High Bandwidth ◽  
Network Technologies

Networking connectivity is increasingly based on wireless network technologies, especially in developing nations where the wired network infrastructure is not accessible to a large segment of the population. Wireless data network technologies based on 2G and 3G are quite common globally; 4G-based deployments are on the rise during the past few years. At the same time, the increasing high-bandwidth and low-latency requirements of mobile applications has propelled the Third Generation Partnership Project (3GPP) standards organization to develop standards for the next generation of mobile networks, based on recent advances in wireless communication technologies. This standard is called the Fifth Generation (5G) wireless network standard. This paper presents a high-level overview of the important architectural components, of the advanced communication technologies, of the advanced networking technologies such as Network Function Virtualization and other important aspects that are part of the 5G network standards. The paper also describes some of the common future generation applications that require low-latency and high-bandwidth communications.

scholarly journals Research on predictive sliding mode control strategy for horizontal vibration of ultra-high-speed elevator car system based on adaptive fuzzy

2021 ◽  
Vol 54 (3-4) ◽  
pp. 360-373
Author(s):  
Hong Wang ◽  
Mingqin Zhang ◽  
Ruijun Zhang ◽  
Lixin Liu
Keyword(s):  
Sliding Mode Control ◽  
High Speed ◽  
Sliding Mode ◽  
Mode Switching ◽  
Parameter Uncertainties ◽  
Horizontal Vibration ◽  
Adaptive Fuzzy ◽  
Mode Control ◽  
System A ◽  
Ultra High Speed

In order to effectively suppress horizontal vibration of the ultra-high-speed elevator car system. Firstly, considering the nonlinearity of guide shoe, parameter uncertainties, and uncertain external disturbances of the elevator car system, a more practical active control model for horizontal vibration of the 4-DOF ultra-high-speed elevator car system is constructed and the rationality of the established model is verified by real elevator experiment. Secondly, a predictive sliding mode controller based on adaptive fuzzy (PSMC-AF) is proposed to reduce the horizontal vibration of the car system, the predictive sliding mode control law is achieved by optimizing the predictive sliding mode performance index. Simultaneously, in order to decrease the influence of uncertainty of the car system, a fuzzy logic system (FLS) is designed to approximate the compound uncertain disturbance term (CUDT) on-line. Furthermore, the continuous smooth hyperbolic tangent function (HTF) is introduced into the sliding mode switching term to compensate the fuzzy approximation error. The adaptive laws are designed to estimate the error gain and slope parameter, so as to increase the robustness of the system. Finally, numerical simulations are conducted on some representative guide rail excitations and the results are compared to the existing solution and passive system. The analysis has confirmed the effectiveness and robustness of the proposed control method.

Design of New Dual-Motor Independent Drive System for Electric Vehicle

2012 ◽  
Vol 591-593 ◽  
pp. 251-258
Author(s):  
Wen Wei Wang ◽  
Cheng Lin ◽  
Wan Ke Cao ◽  
Jiao Yang Chen
Keyword(s):  
Electric Vehicle ◽  
Network Architecture ◽  
High Speed ◽  
Simulation Analysis ◽  
Stability Control ◽  
Driving System ◽  
System A ◽  
Important Direction ◽  
Time Predictability ◽  
Information Scheduling

Multi-motor wheel independent driving technology is an important direction of electric vehicle(EV). Based on the analysis of the features of existing independent driving system of electric vehicle, a new dual-motor independent driving system configuration was designed. Complete parameters matching and simulation analysis of the system include motor, reducer, and battery. Distributed control network architecture based on high-speed CAN bus was developed, and information scheduling was optimized and real-time predictability was analyzed based on the rate monotonic (RM) algorithm and jitter margin index. The vehicle lateral stability control was achieved based on coordinated electro-hydraulic active braking. Based on the new dual-motor independent driving system, a new battery electric car was designed and tested. The results show that the vehicle has excellent dynamic and economic performance.

Research on Reconfigurable High-Speed Serial Bus Used in High-Reliability Embedded Computer

2010 ◽  
Vol 20-23 ◽  
pp. 774-778
Author(s):  
Rui Ding ◽  
Yong Qin Hu ◽  
Wei Gong Zhang ◽  
Bo Yang
Keyword(s):  
Computer System ◽  
High Speed ◽  
Communication Protocol ◽  
High Reliability ◽  
Dynamic Reconfiguration ◽  
System A ◽  
Embedded Computer ◽  
Key Points ◽  
Application Scope

The characteristics and limitations of the buses, which are widely used nowadays, are analyzed in this paper. Because these buses don’t adapt to the high-reliability embedded computer system, a novel bus is proposed which is characterized by its high-reliability. And its capacity is reached through its unique datum’s dynamic reconfiguration mechanism. The basic architecture and communication protocol are presented in this paper. And then the key points during realization of this bus are discussed. Finally, the probably application scope and prospects are indicated.

Some Observations of Chaotic Vibration Phenomena in High-Speed Rotordynamics

1991 ◽  
Vol 113 (1) ◽  
pp. 50-57 ◽  
Author(s):  
F. F. Ehrich
Keyword(s):  
Numerical Model ◽  
High Speed ◽  
Chaotic Behavior ◽  
Narrow Region ◽  
System A ◽  
Vibratory Response ◽  
Local Contact ◽  
Jeffcott Rotor ◽  
Subharmonic Response ◽  
Static Part

Subharmonic response in rotordynamics may be encountered when a rotor is operated with its rotational centerline eccentric to that of a close clearance static part, so that local contact can take place during each orbit when the rotor is excited by residual unbalance. The rotor will tend to bounce at or near its fundamental frequency when the rotor is operated at or near a speed which is a whole number [n] times that frequency. Using a simple numerical model of a Jeffcott rotor mounted on a nonlinear spring, it is found that the vibratory response in the transition zone midway between adjacent zones of subharmonic response has all the characteristics of chaotic behavior. The transition from subharmonic to chaotic response has a complex substructure which involves a sequence of bifurcations of the orbit with variations in speed. This class of rotordynamic behavior was confirmed and illustrated by experimental observations of the vibratory response of a high-speed turbomachine, operating at a speed between 8 and 9 times its fundamental rotor frequency when in local contact across a clearance in the support system. A narrow region between zones of 8th order and 9th order subharmonic response was identified where the response had all the characteristics of the chaotic motion identified in the numerical model.

scholarly journals On Ultra-Reliable Low Latency Multipath TCP For Connected Autonomous Vehicles

2021 ◽  
Author(s):  
Shiva Raj Pokhrel ◽  
Neeraj Kumar ◽  
Anwar Walid
Keyword(s):  
Autonomous Vehicles ◽  
High Speed ◽  
Data Communication ◽  
Low Latency ◽  
Data Traffic ◽  
Mathematical Study ◽  
Multipath Tcp ◽  
Multiple Network ◽  
Very High ◽  
Delay Variation

Connected Autonomous Vehicles (CAVs) are Not-So-Futuristic. CAVs will be highly dynamic by intelligently exploiting multipath communication over several radio technologies, such as high-speed WiFi and 5G and beyond networks. Yet, the likelihood of data communication loss can be very high and/, or packets arrive at the destination not in correct working order due to erratic and mixed time-varying wireless links. Furthermore, the vehicular data traffic is susceptible to loss and delay variation,which recommends the need to investigate new multipath TCP(MPTCP) protocols for ultra-reliable low latency communication(URLLC) over such heterogeneous networks while reassuring CAVs’ needs. We undertake the challenge by jointly considering network coding and balanced linked adaptation for performing coupled congestion control across multiple wireless paths.Consequently, the proposed low delay MPTCP framework for connecting autonomous vehicles is efficient and intelligent by design. We conduct a rigorous convergence analysis of the MPTCP design framework. In summation, we provide a detailed mathematical study and demonstrate that the latency penalty for the URLLC-MPTCP developed over these networks becomes negligible when considering the possible benefits that multiple network convergence could offer. Our extensive emulation results demonstrate all these lucrative features of URLLC-MPTCP.

Simultaneous Time-Frequency Control of Multi-Dimensional Micro-Milling Instability

2012 ◽  
Author(s):  
Meng-Kun Liu ◽  
Eric B. Halfmann ◽  
C. Steve Suh
Keyword(s):  
Frequency Response ◽  
High Speed ◽  
Frequency Control ◽  
External Perturbation ◽  
Micro Milling ◽  
Time Frequency ◽  
System A ◽  
Control Concept ◽  
The Time Domain ◽  
Tool Damage

A novel control concept is presented for the online control of a high-speed micro-milling model system in the time and frequency domains concurrently. Micro-milling response at high-speed is highly sensitive to machining condition and external perturbation, easily deteriorating from bifurcation to chaos. When losing stability, milling time response is no longer periodic and the frequency response becomes broadband, rendering aberrational tool chatter and probable tool damage. The controller effectively mitigates the nonlinear vibration of the tool in the time domain and at the same time confines the frequency response from expanding and becoming chaotically broadband. The simultaneous time-frequency control is achieved through manipulating wavelet coefficients, thus not limited by the increasing bandwidth of the chaotic system — a fundamental restraint that deprives contemporary controller designs of validity and effectiveness. The feedforward feature of the control concept prevents errors from re-entering the control loop and inadvertently perturbing the sensitive micro-milling system. Because neither closed-form nor linearization is required, the innate, genuine features of the micro-milling response are faithfully retained.

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