To enhance the fidelity and accuracy of the simulation of communication networks,hardware-in-the-loop（HITL） simulation was employed.HITL simulation methods was classified into three categories,of which the merits an...To enhance the fidelity and accuracy of the simulation of communication networks,hardware-in-the-loop（HITL） simulation was employed.HITL simulation methods was classified into three categories,of which the merits and shortages were compared.Combing system-in-the-loop（SITL） simulation principle with high level architecture（HLA）,an HITL simulation model of asynchronous transfer mode（ATM） network was constructed.The throughput and end-to-end delay of all-digital simulation and HITL simulation was analyzed,which showed that HITL simulation was more reliable and effectively improved the simulation credibility of communication network.Meanwhile,HLA-SITL method was fast and easy to achieve and low-cost during design lifecycle.Thus,it was a feasible way to research and analyze the large-scale network.展开更多
ECFD （erroneous cell tail drop）, a buffer management optimization strategy is suggested which can improve the utilization of buffer resources in satellite ATM （asynchronous transfer mode） networks. The strategy, i...ECFD （erroneous cell tail drop）, a buffer management optimization strategy is suggested which can improve the utilization of buffer resources in satellite ATM （asynchronous transfer mode） networks. The strategy, in which erroneous cells caused by satellite channel and the following cells that belong to the same PDU （protocol data Unit） are discarded, concerns non-real-time data services that use higher layer protocol for retransmission. Based on EPD （early packet drop） policy, mathematical models are established with and without ECTD. The numerical results show that ECTD would optimize buffer management and improve effective throughput （goodput）, and the increment of goodput is relative to the CER （cell error ratio） and the PDU length. The higher their values are, the greater the increment. For example, when the average PDU length values are 30 and 90, the improvement of goodput are respectively about 4% and 10%.展开更多
Recent efforts to add new services to the wide-band code division multiple accesses （WCDMA） system have increased interest in network processor （NP）-based routers that are easy to extend and evolve. In this paper,...Recent efforts to add new services to the wide-band code division multiple accesses （WCDMA） system have increased interest in network processor （NP）-based routers that are easy to extend and evolve. In this paper, an application of NPs in routing engine module （REM） of radio network controller （RNC） in WCDMA system is proposed. The measuring results show that NPs have good performance and efficiency in routing traffic of the communication network and the simulation verifies the fast forwarding function of NPs.展开更多
The dissertation studies the architecture of broadband intelligent network (BIN) and implementation of video conference based on ATM network and of multicast routing problem on video conference using BIN under the aid...The dissertation studies the architecture of broadband intelligent network (BIN) and implementation of video conference based on ATM network and of multicast routing problem on video conference using BIN under the aid of the important task Study of IN and B ISDN Integration (69896244) sponsored by National Natural Science Fund. A lot of points of view and solutions are present. The main contributions in the dissertation are as follows:\; (1) Design the new architecture of BIN and improve the architecture of BIN proposed by ITU T. It is easy to set up the connections of video conference using the new architecture of BIN.\; (2) Present the detailed scheme that BIN controls and implements video conference without specialized resource function, study the scheme of all the media on video conference transmitted and switched under the control of BIN, and discuss how to implement point to multipoint communications using BIN.\; (3) First present the scheme of implementing multicast routing algorithms on video conference using BIN.\; (4) Explicitly introduce a series of concepts including neighboring node, neighboring node set, neighboring edge, then propose an Adjustable Dynamic Multicast (ADM) routing algorithm which is suitable for video conference, analyze its performances, and prove the algorithm is appropriate and feasible.\; (5) Develop a degree constrained dynamic multicast (DADM) routing algorithm which can find less cost multicast routing tree. The results of simulation and experiments confirm that DADM algorithm can find the less cost multicast tree. Finally, analyze the relation between the size of degree constrained and value of multicast tree cost.\; (6) Present a delay constrained dynamic multicast routing algorithm suitable for video conference characteristic, and advise a series of schemes reducing the delay of transmitting all the media on videoconference.\; (7) First propose implementing the reliable multicast routing transport protocol using BIN, thereby ACK implosion problem can be solved. The protocol only requires finite memory and is scalable.展开更多
A brief introduction to the first ATM Multiplexing Equipment in China is given, which includes its characteristics, and architecture of hardware and software. Other topics such as the key issues in design and implemen...A brief introduction to the first ATM Multiplexing Equipment in China is given, which includes its characteristics, and architecture of hardware and software. Other topics such as the key issues in design and implementation of its parts, and the major techniques already acquired are also discussed. This paper is expected to be helpful for the research and development of the relevant ATM equipment.展开更多
基金Supported by the National Natural Science Foundation of China (61101129)Specialized Research Fund for the Doctoral Program of Higher Education(20091101110019)
文摘To enhance the fidelity and accuracy of the simulation of communication networks,hardware-in-the-loop（HITL） simulation was employed.HITL simulation methods was classified into three categories,of which the merits and shortages were compared.Combing system-in-the-loop（SITL） simulation principle with high level architecture（HLA）,an HITL simulation model of asynchronous transfer mode（ATM） network was constructed.The throughput and end-to-end delay of all-digital simulation and HITL simulation was analyzed,which showed that HITL simulation was more reliable and effectively improved the simulation credibility of communication network.Meanwhile,HLA-SITL method was fast and easy to achieve and low-cost during design lifecycle.Thus,it was a feasible way to research and analyze the large-scale network.
文摘ECFD （erroneous cell tail drop）, a buffer management optimization strategy is suggested which can improve the utilization of buffer resources in satellite ATM （asynchronous transfer mode） networks. The strategy, in which erroneous cells caused by satellite channel and the following cells that belong to the same PDU （protocol data Unit） are discarded, concerns non-real-time data services that use higher layer protocol for retransmission. Based on EPD （early packet drop） policy, mathematical models are established with and without ECTD. The numerical results show that ECTD would optimize buffer management and improve effective throughput （goodput）, and the increment of goodput is relative to the CER （cell error ratio） and the PDU length. The higher their values are, the greater the increment. For example, when the average PDU length values are 30 and 90, the improvement of goodput are respectively about 4% and 10%.
文摘Recent efforts to add new services to the wide-band code division multiple accesses （WCDMA） system have increased interest in network processor （NP）-based routers that are easy to extend and evolve. In this paper, an application of NPs in routing engine module （REM） of radio network controller （RNC） in WCDMA system is proposed. The measuring results show that NPs have good performance and efficiency in routing traffic of the communication network and the simulation verifies the fast forwarding function of NPs.
文摘The dissertation studies the architecture of broadband intelligent network (BIN) and implementation of video conference based on ATM network and of multicast routing problem on video conference using BIN under the aid of the important task Study of IN and B ISDN Integration (69896244) sponsored by National Natural Science Fund. A lot of points of view and solutions are present. The main contributions in the dissertation are as follows:\; (1) Design the new architecture of BIN and improve the architecture of BIN proposed by ITU T. It is easy to set up the connections of video conference using the new architecture of BIN.\; (2) Present the detailed scheme that BIN controls and implements video conference without specialized resource function, study the scheme of all the media on video conference transmitted and switched under the control of BIN, and discuss how to implement point to multipoint communications using BIN.\; (3) First present the scheme of implementing multicast routing algorithms on video conference using BIN.\; (4) Explicitly introduce a series of concepts including neighboring node, neighboring node set, neighboring edge, then propose an Adjustable Dynamic Multicast (ADM) routing algorithm which is suitable for video conference, analyze its performances, and prove the algorithm is appropriate and feasible.\; (5) Develop a degree constrained dynamic multicast (DADM) routing algorithm which can find less cost multicast routing tree. The results of simulation and experiments confirm that DADM algorithm can find the less cost multicast tree. Finally, analyze the relation between the size of degree constrained and value of multicast tree cost.\; (6) Present a delay constrained dynamic multicast routing algorithm suitable for video conference characteristic, and advise a series of schemes reducing the delay of transmitting all the media on videoconference.\; (7) First propose implementing the reliable multicast routing transport protocol using BIN, thereby ACK implosion problem can be solved. The protocol only requires finite memory and is scalable.
文摘A brief introduction to the first ATM Multiplexing Equipment in China is given, which includes its characteristics, and architecture of hardware and software. Other topics such as the key issues in design and implementation of its parts, and the major techniques already acquired are also discussed. This paper is expected to be helpful for the research and development of the relevant ATM equipment.
