Digital television transmission based on asynchronous transfer mode

This paper introduces a method to realize digital television transmission based on asynchronous transfer mode (ATM), a technology based on fast packet switching. Choosing the integral multiple length of an ATM cell payload to equal to the length of an MPEG transport stream packet, an MPEG transport stream packet can be inextenso loaded by several ATM cells and trans-formed into ATM cells. Using ATM virtual connection technology and B-ISDN, the interoperability between ATM and DTV may be realized, and DTV signal transmission may also be realized finally.

MODELING OF THE PRIORITY SCHEDULING INPUT-LINE GROUP OUTPUT WITH MULTI-CHANNEL IN ATM EXCHANGE SYSTEM

In this paper, an extended Kendall model for the priority scheduling input-line group output with multi-channel in Asynchronous Transfer Mode （ATM） exchange system is proposed and then the mean method is used to model mathematically the non-typical non-anticipative PRiority service （PR） model. Compared with the typical and non-anticipative PR model, it expresses the characteristics of the priority scheduling input-line group output with multi-channel in ATM exchange system. The simulation experiment shows that this model can improve the HOL block and the performance of input-queued ATM switch network dramatically. This model has a better developing prospect in ATM exchange system.

Research on Asynchronous Transfer of DTV Video Signal

Digital TV (DTV) video signal transmission over ATM network is emphasized on.Some important problems are introduced about TV video signals asynchronous transfer to network application client, and the idea of video transfer design is discussed. The contents mainly include the DTV video streams asynchronous transfer topology, compressed coding adopted ATM network, asynchronous transfer efficiency and some problems of DTV video transmission in ATM network .

STF:PROVIDE RATE GUARANTEES IN INPUT-QUEUED SWITCH

A QoS-aware input-queued scheduling algorithm, called Smallest Timestamp First (STF), is proposed, which is improved upon iSLIP and can allocate bandwidth among inputs sharing a common output based on their reservation by assigning suitable finishing tiniest-amps to contending cells. STF can also provide isolation between flows that share a common output, link. Misbehaving flows will be restricted to guarantee the behaving flows' bandwidth. Simulations prove the feasibility of our algorithm.

Hardware-in-the-loop simulation of communication networks

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.

异步传输模式网络设计自愈研究

在ATM网络设计中,自愈是指网络发生故障时,在不需要人工干预的情况下,就能很快恢复维持服务连贯性。这包括两个方面:网络计划和运作,其中网络计划包括最佳/接近最佳网络设计,网络运作利用分配冗余信道来处理恢复机制。网络的自愈能力可以用存储率(restoration ratio)来反映,这里采用聚集存储率(aggregate restoration ratio),研究的目的是为了比较基于通路和链接恢复网络自愈能力的不同,以及不同设计因素对自愈能力的影响。

Buffer management optimization strategy for satellite ATM

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%.

A COMBINED ADMISSION CONTROL ALGORITHM WITH DA PROTOCOL FOR SATELLITE ATM NETWORKS

Admission control is an important strategy for Quality of Service (QoS) provisioning in Asynchro- nous Transfer Mode (ATM) networks. Based on a control-theory model of resources on-Demand Allocation (DA) protocol, the paper studies the effect of the protocol on the statistical characteristics of network traffic, and proposes a combined connection admission control algorithm with the DA protocol to achieve full utiliza- tion of link resources in satellite communication systems. The proposed algorithm is based on the cross-layer-design approach. Theoretical analysis and system simulation results show that the proposed algo- rithm can admit more connections within certain admission thresholds than one that does not take into account the DA protocol. Thus, the proposed algorithm can increase admission ratio of traffic sources for satellite ATM networks and improve satellite link utilization.

The Application of NPs in WCDMA Systems

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.

A Study of Broadband Intelligent Network Implementing Video Conference and Multicast Routing Algorithm

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.

On the Implementation and Key Issues of an ATM Multiplexing Equipment

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.