ISSN 
2000 Vol. 29, No. 4
2000, 29(4): 331-336.
Abstract:
In this paper, a discussion of research on IP over WDM networks directly is provided. The network structure including optical add/drop multiplexer and optical cross-connect is described. The physical and logical structures are presented with an example. The frame structure, routing and assignment of wavelength, and network survivability are discussed.
In this paper, a discussion of research on IP over WDM networks directly is provided. The network structure including optical add/drop multiplexer and optical cross-connect is described. The physical and logical structures are presented with an example. The frame structure, routing and assignment of wavelength, and network survivability are discussed.
2000, 29(4): 337-341.
Abstract:
The development situation of WDM technologies is introduced in this paper. The primary technological characteristics are analyzed, and the key WDM technologies such as laser, wavelength division multiplexer, EDFA etc.are addressed. Some issues in WDM system are also discussed.
The development situation of WDM technologies is introduced in this paper. The primary technological characteristics are analyzed, and the key WDM technologies such as laser, wavelength division multiplexer, EDFA etc.are addressed. Some issues in WDM system are also discussed.
2000, 29(4): 342-346.
Abstract:
In this paper, the transmission properties of fiber are investigated. According to the application requirements for optical networking, the types of fiber and its application design are described and analyzed in detail, and the optimum application of fiber is addressed.
In this paper, the transmission properties of fiber are investigated. According to the application requirements for optical networking, the types of fiber and its application design are described and analyzed in detail, and the optimum application of fiber is addressed.
2000, 29(4): 347-350.
Abstract:
In this paper, the conception and the advantages of the wave divided multiplexing technique used in all-optical networks are introduced, and the techniques of optical cross-connect multiplexing, optical add-drop multiplexing, network managing and auto-healing ring are discussed. In the all-optical networks, the main technique upgraded from traditional networks is optical routing in the network nods. The superiority of large capacity and escalation in all-optical networks is also introduced.
In this paper, the conception and the advantages of the wave divided multiplexing technique used in all-optical networks are introduced, and the techniques of optical cross-connect multiplexing, optical add-drop multiplexing, network managing and auto-healing ring are discussed. In the all-optical networks, the main technique upgraded from traditional networks is optical routing in the network nods. The superiority of large capacity and escalation in all-optical networks is also introduced.
2000, 29(4): 351-355.
Abstract:
In this paper, a passive optical network based on ATM (APON) is presented, and APON's access mechanism is anatomized. APON needs a special MAC protocol because of its special structure. Setting up a queuing model with priority, a theoretic analysis of APON system for the support of services with several priorities is given, and some useful conclusion is met.
In this paper, a passive optical network based on ATM (APON) is presented, and APON's access mechanism is anatomized. APON needs a special MAC protocol because of its special structure. Setting up a queuing model with priority, a theoretic analysis of APON system for the support of services with several priorities is given, and some useful conclusion is met.
2000, 29(4): 356-360.
Abstract:
This paper proposes the scheme, hardware implementation and experiment result of HFC. The system is composed of upward and downward channel optic transmission equipments, shifting frequency equipment, monitoring spectrum equipment, modulator/demodulator and network management software. The novel characteristics include intelligent fiber optic transmission equipment with remote monitoring and controlling, upward spreading channel spectrum using frequency shifting and multiplexing, online monitoring of the upward channel spectrum,and Chinese network management system.
This paper proposes the scheme, hardware implementation and experiment result of HFC. The system is composed of upward and downward channel optic transmission equipments, shifting frequency equipment, monitoring spectrum equipment, modulator/demodulator and network management software. The novel characteristics include intelligent fiber optic transmission equipment with remote monitoring and controlling, upward spreading channel spectrum using frequency shifting and multiplexing, online monitoring of the upward channel spectrum,and Chinese network management system.
2000, 29(4): 361-364.
Abstract:
In this paper, a new designing scheme of gigabit rate digital fiber optic transmission system is introduced including multiplexer, encoder, decoder, demultiplexer, scheme design of transmitterand received, access and recovery of digitized video and multirate service, and high speed PCB design. Low cost G-Link chip is used in the system according to characters of digital fiber optic transmission. The experimental results show that the scheme is feasible and favorable.
In this paper, a new designing scheme of gigabit rate digital fiber optic transmission system is introduced including multiplexer, encoder, decoder, demultiplexer, scheme design of transmitterand received, access and recovery of digitized video and multirate service, and high speed PCB design. Low cost G-Link chip is used in the system according to characters of digital fiber optic transmission. The experimental results show that the scheme is feasible and favorable.
2000, 29(4): 365-368.
Abstract:
In this paper, space station information systems are described, including avionics supported functions and information system functions. In space stations, the technology of fiber optical communication has its own advantages:wider bandwidth fiber than coax cable; capable of anti-radialization and an-electromagnetism; small volume and light weight of the optical fiber, etc., which play a key role in information systems and administration systems in space stations.
In this paper, space station information systems are described, including avionics supported functions and information system functions. In space stations, the technology of fiber optical communication has its own advantages:wider bandwidth fiber than coax cable; capable of anti-radialization and an-electromagnetism; small volume and light weight of the optical fiber, etc., which play a key role in information systems and administration systems in space stations.
2000, 29(4): 369-372.
Abstract:
The background of all-optical networks based on wavelength-division multiplexing is briefly analyzed in this paper, and the basic concepts and advantages of AON are introduced. Two-fiber unidirectional path-switched rings, four-fiber bidirectional self-healing rings and their schemes for network protection are mainly discussed. Compared to mesh networks, restoration in mesh networks is more important and efficient.
The background of all-optical networks based on wavelength-division multiplexing is briefly analyzed in this paper, and the basic concepts and advantages of AON are introduced. Two-fiber unidirectional path-switched rings, four-fiber bidirectional self-healing rings and their schemes for network protection are mainly discussed. Compared to mesh networks, restoration in mesh networks is more important and efficient.
2000, 29(4): 373-376.
Abstract:
Recent development and applications of distributed optical fiber stress sensor are described briefly. Based on the theory that coupling coefficient is related to external force, a distributed optical fiber stress sensor is introduced. Distribution of external force is measured by polarization coupling coherence. The principle of location and measuring strength of stress is discussed. The influence of light and polarizer and other things upon the sensitivity and resolving power of the sensor, is discussed. SLD is used as light and proton-exchange LiNbO3 wave-guide is used as polarizer. At the wavelength of 1.3 μm, the resolution of the sensor is better by ±10 cm and its sensitivity is better by 5%.
Recent development and applications of distributed optical fiber stress sensor are described briefly. Based on the theory that coupling coefficient is related to external force, a distributed optical fiber stress sensor is introduced. Distribution of external force is measured by polarization coupling coherence. The principle of location and measuring strength of stress is discussed. The influence of light and polarizer and other things upon the sensitivity and resolving power of the sensor, is discussed. SLD is used as light and proton-exchange LiNbO3 wave-guide is used as polarizer. At the wavelength of 1.3 μm, the resolution of the sensor is better by ±10 cm and its sensitivity is better by 5%.
2000, 29(4): 377-380.
Abstract:
In this paper, an integrated optical modulator is proposed and analyzed, which is constructed in a fin line geometry and can be applied to a Doppler radar for processing the Doppler frequency shift.The process has the advantage of immunity to lightning and other electromagnetic interference by the use of optical fiber transmission.
In this paper, an integrated optical modulator is proposed and analyzed, which is constructed in a fin line geometry and can be applied to a Doppler radar for processing the Doppler frequency shift.The process has the advantage of immunity to lightning and other electromagnetic interference by the use of optical fiber transmission.
2000, 29(4): 381-383.
Abstract:
A new scheme for word synchronization in pulse position modulation is proposed. The most important issue in pulse position modulation is the receiver synchronization subsystem which maintains necessary decoder timing, thus accomplishes the PPM data deduction which contains three levels of Synchronization (slot, word and frame). In the new scheme proposed, the phase lock loop is avoided and the digital logical circuit is used.
A new scheme for word synchronization in pulse position modulation is proposed. The most important issue in pulse position modulation is the receiver synchronization subsystem which maintains necessary decoder timing, thus accomplishes the PPM data deduction which contains three levels of Synchronization (slot, word and frame). In the new scheme proposed, the phase lock loop is avoided and the digital logical circuit is used.
2000, 29(4): 384-386.
Abstract:
This paper proposed a scheme of multiplexing fast ethernet signal (100BASE-TX) to gigabit-speed, sending it over to peer end, and then demultiplexing it to original signal. The most important issue of synchronization is discussed in detail. The scheme is implemented in hardware and works well.
This paper proposed a scheme of multiplexing fast ethernet signal (100BASE-TX) to gigabit-speed, sending it over to peer end, and then demultiplexing it to original signal. The most important issue of synchronization is discussed in detail. The scheme is implemented in hardware and works well.
2000, 29(4): 387-391.
Abstract:
This paper introduces and compares the architectures of active networks, and analyzes their main applications including network management, congestion control, multicasting and web cache, which might give great improvement of performance and intelligence to existing communication networks. This paper also enumerates some technical issues of security of active networks, and gives a recommendation on operating steps to implement secure active networks. The developing status is also summarized and a long-range survey system is introduced.
This paper introduces and compares the architectures of active networks, and analyzes their main applications including network management, congestion control, multicasting and web cache, which might give great improvement of performance and intelligence to existing communication networks. This paper also enumerates some technical issues of security of active networks, and gives a recommendation on operating steps to implement secure active networks. The developing status is also summarized and a long-range survey system is introduced.
2000, 29(4): 392-396.
Abstract:
With the widely used SNMP protocol, this paper introduces the concept of active network and discusses its applications in the field of network management. The small package and the management by delegation and remote test in digital networks are investigated.
With the widely used SNMP protocol, this paper introduces the concept of active network and discusses its applications in the field of network management. The small package and the management by delegation and remote test in digital networks are investigated.
2000, 29(4): 397-401.
Abstract:
In this paper, some techniques (active network, CORBA, Java RMI etc.) are presented which can realize remote applications. Active networks is also introduced. Compared with other techniques, active network is the most promising one. Based on the designing idea of active networks, a simple remote test model is proposed using Java and some remote test programs.
In this paper, some techniques (active network, CORBA, Java RMI etc.) are presented which can realize remote applications. Active networks is also introduced. Compared with other techniques, active network is the most promising one. Based on the designing idea of active networks, a simple remote test model is proposed using Java and some remote test programs.
2000, 29(4): 402-405.
Abstract:
This paper introduced the concepts of active networks, network security, and security active network environment (SAM), and analyzes the security of active networks. With the describing of SANE and current developing status in this field, this paper emphasizes the importance of safety and security in active networks. It is shown that the research and solution of active networks are the precondition of its applications.
This paper introduced the concepts of active networks, network security, and security active network environment (SAM), and analyzes the security of active networks. With the describing of SANE and current developing status in this field, this paper emphasizes the importance of safety and security in active networks. It is shown that the research and solution of active networks are the precondition of its applications.
2000, 29(4): 406-411.
Abstract:
In this paper, a new architecture of optical internet is introduced which combines IP networks and optical transport networks using dense wavelength division multiplexing technology. The optical transport network is based on optical circuit switching, which means there is no optical packet switching used in the networks. The reference model, the basic framework for running IP over WDM, and the defination of optical frame structure are discussed in detail. The issues of optical flow switching are overviewed.
In this paper, a new architecture of optical internet is introduced which combines IP networks and optical transport networks using dense wavelength division multiplexing technology. The optical transport network is based on optical circuit switching, which means there is no optical packet switching used in the networks. The reference model, the basic framework for running IP over WDM, and the defination of optical frame structure are discussed in detail. The issues of optical flow switching are overviewed.
2000, 29(4): 412-416.
Abstract:
A Survivable Solution for SDH over WDM networks is proposed in this paper The key issues associated with lightpath-based 1+1 multiplex section protecion (MSP) and 2 optical channel multiplex section/shared protection ring (2OCH MS/SPRing) are discussed. According to the requirements of transfer rate and recover time of the traffic between different node pairs, lightpath-based 1+1 MSP and 2OCH MS/SPRing are chosen to provide efficient transporting and protection functions. With protected SDH over unprotected WDM optical layer, all the traffic can be protected efficiently.
A Survivable Solution for SDH over WDM networks is proposed in this paper The key issues associated with lightpath-based 1+1 multiplex section protecion (MSP) and 2 optical channel multiplex section/shared protection ring (2OCH MS/SPRing) are discussed. According to the requirements of transfer rate and recover time of the traffic between different node pairs, lightpath-based 1+1 MSP and 2OCH MS/SPRing are chosen to provide efficient transporting and protection functions. With protected SDH over unprotected WDM optical layer, all the traffic can be protected efficiently.
2000, 29(4): 417-421.
Abstract:
In this paper, a new resilient network model aimed at minimizing total fiber length is established and the influence of wavelength conversion on design of restorable multi-fiber WDM networks is studied simultaneously. The results show that introducing wavelength converters has no benefits to reduce the cost of multi-fiber networks without considering survivability, and using wavelength converters can reduce the total fiber length in evidence, especially with link protection especially.
In this paper, a new resilient network model aimed at minimizing total fiber length is established and the influence of wavelength conversion on design of restorable multi-fiber WDM networks is studied simultaneously. The results show that introducing wavelength converters has no benefits to reduce the cost of multi-fiber networks without considering survivability, and using wavelength converters can reduce the total fiber length in evidence, especially with link protection especially.
2000, 29(4): 422-428.
Abstract:
The integration of different technologies such as ATM over SDH multilayer transport networks raises many questions regarding the coordination of the individual network layers. In particular, in the area of network survivability, much can be gained by a better alignment of the healing actions taken by different network layers in case of outages. A new self-healing scheme with a new architecture and a new routing algorithm is proposed. Simulation shows that the scheme can achieve quicker restoration than other schemes proposed.
The integration of different technologies such as ATM over SDH multilayer transport networks raises many questions regarding the coordination of the individual network layers. In particular, in the area of network survivability, much can be gained by a better alignment of the healing actions taken by different network layers in case of outages. A new self-healing scheme with a new architecture and a new routing algorithm is proposed. Simulation shows that the scheme can achieve quicker restoration than other schemes proposed.
2000, 29(4): 429-433.
Abstract:
In this paper, the reason why Internet network can not provide quality of service is analyzed, and the according issues are discussed. Some proposed techniques to guarantee the quality of service in IP networks are briefly overviewed. Based on these discussions, this paper uses ATM technology to improve quality of service of IP traffic. Through a deeper view and comparison of some propsed schemes, a new queueing algorithm to guarantee the quality of service of IP traffic is proposed. The performance of the proposed algorithm is proved through simulation.
In this paper, the reason why Internet network can not provide quality of service is analyzed, and the according issues are discussed. Some proposed techniques to guarantee the quality of service in IP networks are briefly overviewed. Based on these discussions, this paper uses ATM technology to improve quality of service of IP traffic. Through a deeper view and comparison of some propsed schemes, a new queueing algorithm to guarantee the quality of service of IP traffic is proposed. The performance of the proposed algorithm is proved through simulation.
2000, 29(4): 434-439.
Abstract:
This paper introduces the principle of MPLS (multiprotocol label switching) and discusses how to implement MPLS over traditional ATM switch. The implement structure of MPLS based on ATM is put forward and its relevant key mechanisms are discussed. How to implement IP QoS and traffic engineering using MPLS technology is investigated.
This paper introduces the principle of MPLS (multiprotocol label switching) and discusses how to implement MPLS over traditional ATM switch. The implement structure of MPLS based on ATM is put forward and its relevant key mechanisms are discussed. How to implement IP QoS and traffic engineering using MPLS technology is investigated.
2000, 29(4): 440-444.
Abstract:
In this paper, the cell delay in ATM MUX and output-buffered ATM switch is simulated, Which adopts various packet fair queuing algorithms. The simulation results are analyzed, which show that the isolation property of SCFQ(self clocked fair queuing) is weaker than others. If a CBR group has no connection in which traffic exceeds reservation, as to the maximum cell delay and cell average delay, the difference between per_rate_grouping implementation of WF2Q+ and no_per_rate_grouping implementation of WF2Q+ is negligible. According to the results, a scheduling structure dealing with CBR. VBR. ABR and UBR is proposed, which satisfies the strict delay requirement of CBR and guarantees the throughput of VBR. ABR and UBR. The implementation complexity of the scheduler is also discussed.
In this paper, the cell delay in ATM MUX and output-buffered ATM switch is simulated, Which adopts various packet fair queuing algorithms. The simulation results are analyzed, which show that the isolation property of SCFQ(self clocked fair queuing) is weaker than others. If a CBR group has no connection in which traffic exceeds reservation, as to the maximum cell delay and cell average delay, the difference between per_rate_grouping implementation of WF2Q+ and no_per_rate_grouping implementation of WF2Q+ is negligible. According to the results, a scheduling structure dealing with CBR. VBR. ABR and UBR is proposed, which satisfies the strict delay requirement of CBR and guarantees the throughput of VBR. ABR and UBR. The implementation complexity of the scheduler is also discussed.
2000, 29(4): 445-449.
Abstract:
Recent studies of the network show that the self-similar nature of the traffic has large influences on the network performance. Based on the traditional traffic models, the network performance is often over optimism. In this paper, a formula of cell loss rate of a buffer system under the self-similar traffic is proposed. A call admission control algorithm utilizing the Gaussian assumption of the traffic is given, which deals with the traditional traffic and self-similar traffic as well. Simulation results indicates that this algorithm is rather accurate and fast.
Recent studies of the network show that the self-similar nature of the traffic has large influences on the network performance. Based on the traditional traffic models, the network performance is often over optimism. In this paper, a formula of cell loss rate of a buffer system under the self-similar traffic is proposed. A call admission control algorithm utilizing the Gaussian assumption of the traffic is given, which deals with the traditional traffic and self-similar traffic as well. Simulation results indicates that this algorithm is rather accurate and fast.
2000, 29(4): 450-456.
Abstract:
In this paper, the asymptotic performance of a linear closed-loop congestion control scheme is analyzed in detail. The asymptotic stability of the scheme is proved, which means the system using this control algorithm is free from oscillation in steady state. The effect of background traffic is analyzed under a Brownian assumption using stochastic difference-differential equation model. Based on those results, the issue of parameter adjustment to achieve optimal asymptotic performance in the interference of background traffic is also discussed.
In this paper, the asymptotic performance of a linear closed-loop congestion control scheme is analyzed in detail. The asymptotic stability of the scheme is proved, which means the system using this control algorithm is free from oscillation in steady state. The effect of background traffic is analyzed under a Brownian assumption using stochastic difference-differential equation model. Based on those results, the issue of parameter adjustment to achieve optimal asymptotic performance in the interference of background traffic is also discussed.
