The systematical and scalable frameworks were provided for estimating the blocking probabilities under asynchronous traffic in optical burst switching(OBS) nodes with limited wavelength conversion capability(LWCC) . T...The systematical and scalable frameworks were provided for estimating the blocking probabilities under asynchronous traffic in optical burst switching(OBS) nodes with limited wavelength conversion capability(LWCC) . The relevant system architectures of limited range and limited number of wavelength converters(WCs) deployed by a share-per-fiber(SPF) mode were developed,and the novel theoretical analysis of node blocking probability was derived by combining the calculation of discouraged arrival rate in a birth-death process and two-dimensional Markov chain model of SPF. The simulation results on single node performance verify the accuracy and effectiveness of the analysis models. Under most scenarios,it is difficult to distinguish the plots generated by the analysis and simulation. As the conversion degree increases,the accuracy of the analysis model worsens slightly. However,the utmost error on burst loss probability is far less than one order of magnitude and hence,still allows for an accurate estimate. Some results are of actual significance to the construction of next-generation commercial OBS backbones.展开更多
Time-slotted optical burst switched network is a potential technique to support IP over Wavelength Division Multiplexing (WDM) by introduce Time Division Multiplexing (TDM) channel to Optical Burst Switching (OBS) tec...Time-slotted optical burst switched network is a potential technique to support IP over Wavelength Division Multiplexing (WDM) by introduce Time Division Multiplexing (TDM) channel to Optical Burst Switching (OBS) technology. This paper presents a framework to evaluate blocking performance of time-slot-ted OBS networks with multi-fiber wavelength channels. The proposed model is efficient for not only single class traffic such as individual circuit switch traffics or best-effort traffics but also mixed multi-class traffics. The effectiveness of the proposed model is validated by simulation results. The study shows that blocking per-formance of multi-fiber TS-OBS network is acceptable for future Internet services.展开更多
Fault detection in optical burst switching （OBS） networks will be a challenging task in the future. A novel mechanism based on probe burst （PB） and a new key concept is proposed to detect faults of OBS networks by...Fault detection in optical burst switching （OBS） networks will be a challenging task in the future. A novel mechanism based on probe burst （PB） and a new key concept is proposed to detect faults of OBS networks by sampling the health of data channels, which solve the difficulty of optical monitoring schemes while keeps the transparency of data network to Internet protocol （IP） packets. It takes full advantage of the characteristics of OBS, including architecture and signalling scheme, and introduces the excellent performances of single-hop-test used in electrical communication networks into OBS environment while avoids the shortcoming that any optical burst must undergo an optical-electric-optical （OEO） conversion. Well designed PB can provide exact criterion for judging whether protection/restoration should be excuted according to hard or soft fault identification.展开更多
A new scheduling algorithm, which aims to provide proportional and controllable QoS (Quality of Service) in terms of burst loss probability for OBS (Optical Burst Switching) networks, is proposed on the ba- sis of a s...A new scheduling algorithm, which aims to provide proportional and controllable QoS (Quality of Service) in terms of burst loss probability for OBS (Optical Burst Switching) networks, is proposed on the ba- sis of a survey of QoS schemes in current OBS networks. With simulations, performance analysis and com- parisons are carried out in detail. The results show that, in the proposed scheme, burst loss probabilities are proportional to the given factors and the control of QoS performance can be achieved with better performance. This scheme will be beneficial to the OBS network management and the tariff policy making.展开更多
National R&D activities on optical switching networkare introduced. Optical switching network testbedswere established in China including 3T-net andOBS ring and mesh network test-bed with the supportof national &#...National R&D activities on optical switching networkare introduced. Optical switching network testbedswere established in China including 3T-net andOBS ring and mesh network test-bed with the supportof national '863' program. As an importantmodule in OPS network, a novel all-optical serialmulticast mode is discussed.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
This paper investigates the untraditional approach of contention resolution in Wavelength Division Multiplexing (WDM) Optical Packet Switching (OPS). The most striking characteristics of the developed switch architect...This paper investigates the untraditional approach of contention resolution in Wavelength Division Multiplexing (WDM) Optical Packet Switching (OPS). The most striking characteristics of the developed switch architecture are: (1) Contention resolution is achieved by a combined sharing of Fiber Delay-Lines (FDLs) and Tunable Optical Wavelength Converters (TOWCs); (2) FDLs are arranged in non-degenerate form, i.e., non-uniform distribution of the delay lines; (3) TOWCs just can perform wavelength conversion in partial continuous wavelength channels, i.e., sparse wavelength conversion. The concrete configurations of FDLs and TOWCs are described and analyzed under non-bursty and bursty traffic scenarios. Simulation results demonstrate that for a prefixed packet loss probability constraint, e.g., 10-6, the developed architecture provides a different point of view in OPS design. That is, combined sharing of FDLs and TOWCs can, effectively, obtain a good tradeoff between the switch size and the cost, and TOWCs which are achieved in sparse form can also decrease the implementing complexity.展开更多
基金Project(60632010) supported by the National Natural Science Foundation of China
文摘The systematical and scalable frameworks were provided for estimating the blocking probabilities under asynchronous traffic in optical burst switching(OBS) nodes with limited wavelength conversion capability(LWCC) . The relevant system architectures of limited range and limited number of wavelength converters(WCs) deployed by a share-per-fiber(SPF) mode were developed,and the novel theoretical analysis of node blocking probability was derived by combining the calculation of discouraged arrival rate in a birth-death process and two-dimensional Markov chain model of SPF. The simulation results on single node performance verify the accuracy and effectiveness of the analysis models. Under most scenarios,it is difficult to distinguish the plots generated by the analysis and simulation. As the conversion degree increases,the accuracy of the analysis model worsens slightly. However,the utmost error on burst loss probability is far less than one order of magnitude and hence,still allows for an accurate estimate. Some results are of actual significance to the construction of next-generation commercial OBS backbones.
基金Founded by the National Natural Science Foundation of China (No.60502005).
文摘Time-slotted optical burst switched network is a potential technique to support IP over Wavelength Division Multiplexing (WDM) by introduce Time Division Multiplexing (TDM) channel to Optical Burst Switching (OBS) technology. This paper presents a framework to evaluate blocking performance of time-slot-ted OBS networks with multi-fiber wavelength channels. The proposed model is efficient for not only single class traffic such as individual circuit switch traffics or best-effort traffics but also mixed multi-class traffics. The effectiveness of the proposed model is validated by simulation results. The study shows that blocking per-formance of multi-fiber TS-OBS network is acceptable for future Internet services.
基金Supported by the National Natural Science Foundation of China （ No. 90304004）, High Technology Research and Development Program of China （ No 2005AA122310）, the Projects of the Science and Technology Council of Chongqing （2005BB2062, 2005AC2089）.
文摘Fault detection in optical burst switching （OBS） networks will be a challenging task in the future. A novel mechanism based on probe burst （PB） and a new key concept is proposed to detect faults of OBS networks by sampling the health of data channels, which solve the difficulty of optical monitoring schemes while keeps the transparency of data network to Internet protocol （IP） packets. It takes full advantage of the characteristics of OBS, including architecture and signalling scheme, and introduces the excellent performances of single-hop-test used in electrical communication networks into OBS environment while avoids the shortcoming that any optical burst must undergo an optical-electric-optical （OEO） conversion. Well designed PB can provide exact criterion for judging whether protection/restoration should be excuted according to hard or soft fault identification.
基金Supported by National Key Project of 863 Program of China (No.2002AA122021), Scientific Research Fund of Chongqing Municipal Education Commission (No.040504 and KJ050504), and Chongqing Science and Technology Commission (CSTC, 2005BB2066).
文摘A new scheduling algorithm, which aims to provide proportional and controllable QoS (Quality of Service) in terms of burst loss probability for OBS (Optical Burst Switching) networks, is proposed on the ba- sis of a survey of QoS schemes in current OBS networks. With simulations, performance analysis and com- parisons are carried out in detail. The results show that, in the proposed scheme, burst loss probabilities are proportional to the given factors and the control of QoS performance can be achieved with better performance. This scheme will be beneficial to the OBS network management and the tariff policy making.
基金supported by the NSFC for Distin guished Young Scholars(No.60325104)NSFC (No.90704006)+4 种基金National 973 Program(No.2007CB310705)National 863 Program(No.2006AA01Z238)PCSIRT(No.IRT0609)ISTCP(No.2006DFA11040)111 Project(No.B07005),P.R.China
文摘National R&D activities on optical switching networkare introduced. Optical switching network testbedswere established in China including 3T-net andOBS ring and mesh network test-bed with the supportof national '863' program. As an importantmodule in OPS network, a novel all-optical serialmulticast mode is discussed.
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.
基金Supported by the National Natural Science Foundation of China (No.69990540).
文摘This paper investigates the untraditional approach of contention resolution in Wavelength Division Multiplexing (WDM) Optical Packet Switching (OPS). The most striking characteristics of the developed switch architecture are: (1) Contention resolution is achieved by a combined sharing of Fiber Delay-Lines (FDLs) and Tunable Optical Wavelength Converters (TOWCs); (2) FDLs are arranged in non-degenerate form, i.e., non-uniform distribution of the delay lines; (3) TOWCs just can perform wavelength conversion in partial continuous wavelength channels, i.e., sparse wavelength conversion. The concrete configurations of FDLs and TOWCs are described and analyzed under non-bursty and bursty traffic scenarios. Simulation results demonstrate that for a prefixed packet loss probability constraint, e.g., 10-6, the developed architecture provides a different point of view in OPS design. That is, combined sharing of FDLs and TOWCs can, effectively, obtain a good tradeoff between the switch size and the cost, and TOWCs which are achieved in sparse form can also decrease the implementing complexity.
基金The Young Junior Faculties Programme of Education Department of Henan Province(No.2011GGJS-081)the Project in Natural Science Research Foundation of Education Department of Henan Province(No.2010A510002)
