In this paper, an Independent Window-Access(IWA) scheme is proposed, and the performance of an input-buffered ATM switching fabric with the IWA scheme is analysed by means of a probability generating function approach...In this paper, an Independent Window-Access(IWA) scheme is proposed, and the performance of an input-buffered ATM switching fabric with the IWA scheme is analysed by means of a probability generating function approach, the closed formulas of the average cell delay and the maximum throughput are given, and results show that the IWA scheme makes the switching fabric have better performances than traditional window-access scheme. The computer simulation results are in good agreement with these analytical results.展开更多
A new structure of optical buffer for resolving ATM cell contention is presented in this paper. It is composed of fiber delay lines, optical waveguide switching array and nonlinear semiconductor optical amplifier. Als...A new structure of optical buffer for resolving ATM cell contention is presented in this paper. It is composed of fiber delay lines, optical waveguide switching array and nonlinear semiconductor optical amplifier. Also, an experimental system for switching ATM cells formed by data at different transmission rates (up to 622MB/s) from different users is reported. The throughput of this system is 1.2Gb/s.展开更多
In this paper,the functions and the architecture of an ATM exchange are summarized.The switching fabrics,the line interface module and the control module are discussed in de-tail.An ATM switching system that adopts th...In this paper,the functions and the architecture of an ATM exchange are summarized.The switching fabrics,the line interface module and the control module are discussed in de-tail.An ATM switching system that adopts the scheme described in this paper has been de-veloped.展开更多
The high-speed on/off valve(HSV)serves as the fundamental component responsible for generating discrete fluids within digital hydraulic systems.As the switching frequency of the HSV increases,the properties of the gen...The high-speed on/off valve(HSV)serves as the fundamental component responsible for generating discrete fluids within digital hydraulic systems.As the switching frequency of the HSV increases,the properties of the generated discrete fluid approach those of continuous fluids.Therefore,a higher frequency response characteristic of HSV is the key to ensure the control accuracy of digital hydraulic systems.However,the current research mainly focuses on its dynamic performance,but neglect its FRC.This paper presents a theoretical analysis demonstrating that the FRC of the HSV can be enhanced by minimizing its switching time.The maximum switching frequency(MSF)is mainly determined by opening dynamic performance when HSV operates with low switching duty ratio(SDR),whereas the closing dynamic performance limits the MSF when HSV operates with high SDR.Building upon these findings,the pre-excitation control algorithm(PECA)is proposed to reduce the switching time of the HSV,and consequently enhance its FRC.Experimental results demonstrate that PECA shortens the opening delay time of HSV by 1.12 ms,the closing delay time by 2.54 ms,and the closing moving time by 0.47 ms in comparison to the existing advanced control algorithms.As a result,a larger MSF of 417 Hz and a wider controllable SDR range from 20%to 70%were achieved at a switching frequency of 250 Hz.Thus,the proposed PFCA in this paper has been verified as an effective and promising approach for enhancing the control performance of digital hydraulic systems.展开更多
This paper analyses the performance of the ATM switch fabric with Combined-Input/ Output Buffering(C-IOB) under two different service principles for the cells at the head of line (HOL) positions of input buffers: Firs...This paper analyses the performance of the ATM switch fabric with Combined-Input/ Output Buffering(C-IOB) under two different service principles for the cells at the head of line (HOL) positions of input buffers: First Come First Service (FCFS)/Random Service(RS) for the set of HOL cells addressed to a given output port with different/same "age" (the waiting time at the HOL position) and Pure Random Service(PRS) for all HOL cells addressed to a given output port regardless of their "ages" while the Queue Loss (QL) transfer scheme is adopted for interaction between input and output buffers in the ATM switch fabric. The results obtained show that the C-IOB ATM switch fabric with PRS service policy and the QL transfer scheme is better than other buffering ATM switch fabrics.展开更多
This paper proposes a new high-performance switching element with the new shared-memory queuing policy, which is called blocked-cell shared-memory (BCSM) queuing. As the name means, instead of buffering all cells thro...This paper proposes a new high-performance switching element with the new shared-memory queuing policy, which is called blocked-cell shared-memory (BCSM) queuing. As the name means, instead of buffering all cells through them, the BCSM switching elements only buffer the blocked cells at their input ports. Theoretic analysis results under the uniform traffic model prove that BCSM switching elements have better performance than shared-memory switching elements.展开更多
This paper introduces the principle of ATM switch, and discusses queueing disciplines and their performances. Authors describe the method of input queueing, output queueing, central queueing, combined input/output que...This paper introduces the principle of ATM switch, and discusses queueing disciplines and their performances. Authors describe the method of input queueing, output queueing, central queueing, combined input/output queuing, combined input/shared queueing, and multistage queueing in detail. They also present the relations between mean waiting time and input load. The queueing disciplines can be used to design the architecture of Asynchronous Transfer Mode (ATM) switch.展开更多
In this approach, three typical implementation schemes of self-healing function in VP switches are discussed and three corresponding queue models for backup-VP self-healing algorithm are established. Computer simulati...In this approach, three typical implementation schemes of self-healing function in VP switches are discussed and three corresponding queue models for backup-VP self-healing algorithm are established. Computer simulations are made to these queue models, and detailed analyses are presented to the effect of both the three implementation schemes of self-healing function and some architecture parameters in VP switches on self-healing performance.展开更多
Optical Packet Switching (OPS) and transmission networks based on Wavelength Division Multiplexing (WDM) have been increasingly deployed in the Internet infrastructure over the last decade in order to meet the huge in...Optical Packet Switching (OPS) and transmission networks based on Wavelength Division Multiplexing (WDM) have been increasingly deployed in the Internet infrastructure over the last decade in order to meet the huge increasing demand for bandwidth. Several different technologies have been developed for optical packet switching such as space switches, broadcast-and-select, input buffered switches and output buffered switches. These architectures vary based on several parameters such as the way of optical buffering, the placement of optical buffers, the way of solving the external blocking inherited from switching technologies in general and the components used to implement the WDM. This study surveys most of the exiting optical packet switching architectures. A simulation-based comparison of input buffered and output buffered architectures is presented. The performance analysis of the selected two architectures is derived using simulation program and compared at different scenarios. We found that the output buffered architectures give better performance than input buffered architectures. The simulation results show that the-broadcast-and-select architecture is attractive in terms that it has lees number of components compared to other switches.展开更多
2.5 Gbit/s ATM optical switching experimental system has been achieved for the first time in P.R.China.This poper describes the architecture of the ATM optical switching system.and gives some key technologies forreali...2.5 Gbit/s ATM optical switching experimental system has been achieved for the first time in P.R.China.This poper describes the architecture of the ATM optical switching system.and gives some key technologies forrealization,e.g. photonic switching matrix, header identification, etc. In addition, the performance, analysis andexperimental results are given.展开更多
文摘In this paper, an Independent Window-Access(IWA) scheme is proposed, and the performance of an input-buffered ATM switching fabric with the IWA scheme is analysed by means of a probability generating function approach, the closed formulas of the average cell delay and the maximum throughput are given, and results show that the IWA scheme makes the switching fabric have better performances than traditional window-access scheme. The computer simulation results are in good agreement with these analytical results.
基金the High Technology Research and Development Programme of China
文摘A new structure of optical buffer for resolving ATM cell contention is presented in this paper. It is composed of fiber delay lines, optical waveguide switching array and nonlinear semiconductor optical amplifier. Also, an experimental system for switching ATM cells formed by data at different transmission rates (up to 622MB/s) from different users is reported. The throughput of this system is 1.2Gb/s.
基金the High Technology Research and Development Programme of china.
文摘In this paper,the functions and the architecture of an ATM exchange are summarized.The switching fabrics,the line interface module and the control module are discussed in de-tail.An ATM switching system that adopts the scheme described in this paper has been de-veloped.
基金Supported by National Natural Science Foundation of China (Grant No.52005441)Young Elite Scientist Sponsorship Program by CAST of China (Grant No.2022-2024QNRC001)+4 种基金Zhejiang Provincial Natural Science Foundation of China (Grant No.LQ21E050017)Zhejiang Provincial“Pioneer”and“Leading Goose”R&D Program of China (Grant Nos.2022C01122,2022C01132)State Key Laboratory of Mechanical System and Vibration of China (Grant No.MSV202316)Fundamental Research Funds for the Provincial Universities of Zhejiang of China (Grant No.RF-A2023007)Research Project of ZJUT of China (Grant No.GYY-ZH-2023075)。
文摘The high-speed on/off valve(HSV)serves as the fundamental component responsible for generating discrete fluids within digital hydraulic systems.As the switching frequency of the HSV increases,the properties of the generated discrete fluid approach those of continuous fluids.Therefore,a higher frequency response characteristic of HSV is the key to ensure the control accuracy of digital hydraulic systems.However,the current research mainly focuses on its dynamic performance,but neglect its FRC.This paper presents a theoretical analysis demonstrating that the FRC of the HSV can be enhanced by minimizing its switching time.The maximum switching frequency(MSF)is mainly determined by opening dynamic performance when HSV operates with low switching duty ratio(SDR),whereas the closing dynamic performance limits the MSF when HSV operates with high SDR.Building upon these findings,the pre-excitation control algorithm(PECA)is proposed to reduce the switching time of the HSV,and consequently enhance its FRC.Experimental results demonstrate that PECA shortens the opening delay time of HSV by 1.12 ms,the closing delay time by 2.54 ms,and the closing moving time by 0.47 ms in comparison to the existing advanced control algorithms.As a result,a larger MSF of 417 Hz and a wider controllable SDR range from 20%to 70%were achieved at a switching frequency of 250 Hz.Thus,the proposed PFCA in this paper has been verified as an effective and promising approach for enhancing the control performance of digital hydraulic systems.
文摘This paper analyses the performance of the ATM switch fabric with Combined-Input/ Output Buffering(C-IOB) under two different service principles for the cells at the head of line (HOL) positions of input buffers: First Come First Service (FCFS)/Random Service(RS) for the set of HOL cells addressed to a given output port with different/same "age" (the waiting time at the HOL position) and Pure Random Service(PRS) for all HOL cells addressed to a given output port regardless of their "ages" while the Queue Loss (QL) transfer scheme is adopted for interaction between input and output buffers in the ATM switch fabric. The results obtained show that the C-IOB ATM switch fabric with PRS service policy and the QL transfer scheme is better than other buffering ATM switch fabrics.
基金Supported by the National Natural Science Foundation of China, Project (NO. 969001405)and the National Key Lab. on ISN
文摘This paper proposes a new high-performance switching element with the new shared-memory queuing policy, which is called blocked-cell shared-memory (BCSM) queuing. As the name means, instead of buffering all cells through them, the BCSM switching elements only buffer the blocked cells at their input ports. Theoretic analysis results under the uniform traffic model prove that BCSM switching elements have better performance than shared-memory switching elements.
文摘This paper introduces the principle of ATM switch, and discusses queueing disciplines and their performances. Authors describe the method of input queueing, output queueing, central queueing, combined input/output queuing, combined input/shared queueing, and multistage queueing in detail. They also present the relations between mean waiting time and input load. The queueing disciplines can be used to design the architecture of Asynchronous Transfer Mode (ATM) switch.
基金Supported by the National Natural Science Foundation of China
文摘In this approach, three typical implementation schemes of self-healing function in VP switches are discussed and three corresponding queue models for backup-VP self-healing algorithm are established. Computer simulations are made to these queue models, and detailed analyses are presented to the effect of both the three implementation schemes of self-healing function and some architecture parameters in VP switches on self-healing performance.
文摘Optical Packet Switching (OPS) and transmission networks based on Wavelength Division Multiplexing (WDM) have been increasingly deployed in the Internet infrastructure over the last decade in order to meet the huge increasing demand for bandwidth. Several different technologies have been developed for optical packet switching such as space switches, broadcast-and-select, input buffered switches and output buffered switches. These architectures vary based on several parameters such as the way of optical buffering, the placement of optical buffers, the way of solving the external blocking inherited from switching technologies in general and the components used to implement the WDM. This study surveys most of the exiting optical packet switching architectures. A simulation-based comparison of input buffered and output buffered architectures is presented. The performance analysis of the selected two architectures is derived using simulation program and compared at different scenarios. We found that the output buffered architectures give better performance than input buffered architectures. The simulation results show that the-broadcast-and-select architecture is attractive in terms that it has lees number of components compared to other switches.
文摘2.5 Gbit/s ATM optical switching experimental system has been achieved for the first time in P.R.China.This poper describes the architecture of the ATM optical switching system.and gives some key technologies forrealization,e.g. photonic switching matrix, header identification, etc. In addition, the performance, analysis andexperimental results are given.
