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
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
为了对先进的长期演进技术(long term evolution-advanced,LTE-Advanced)系统中的多输入多输出(multipleinput and multiple output,MIMO)技术的性能进行评估,简单回顾了LTE-Advanced系统中的2种MIMO技术,即空间复用和空间分集,并介绍...为了对先进的长期演进技术(long term evolution-advanced,LTE-Advanced)系统中的多输入多输出(multipleinput and multiple output,MIMO)技术的性能进行评估,简单回顾了LTE-Advanced系统中的2种MIMO技术,即空间复用和空间分集,并介绍了一种适合LTE-Advanced系统评估的信道模型-IMT-Advanced(international mobile tele-communications-advanced)信道模型。基于该信道模型,通过系统仿真对以上2种关键MIMO技术进行了性能评估。仿真结果表明,不同的MIMO技术、调制方式、码本、复用率及接收方案都对性能有极大的影响。展开更多
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.
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.
文摘为了对先进的长期演进技术(long term evolution-advanced,LTE-Advanced)系统中的多输入多输出(multipleinput and multiple output,MIMO)技术的性能进行评估,简单回顾了LTE-Advanced系统中的2种MIMO技术,即空间复用和空间分集,并介绍了一种适合LTE-Advanced系统评估的信道模型-IMT-Advanced(international mobile tele-communications-advanced)信道模型。基于该信道模型,通过系统仿真对以上2种关键MIMO技术进行了性能评估。仿真结果表明,不同的MIMO技术、调制方式、码本、复用率及接收方案都对性能有极大的影响。
