• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.3
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• pp.379-388
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• 1998

In this paper we propose a DMR-II shared-medium access control protocol which was developed for the ATM access network users to support isochronous and non-isochronous traffics simultaneously under the bandwidth sharing environment, and describe its architecture and operation principles. The DMR-II protocol uses the slotted-ring topology, and gives the higher transmission priority to the isochronous traffic than the non-isochronous traffic. To support the isochronous traffic it uses the slot reservation mechanism, and maintains the delay variation of the isochronous traffic beyond the threshold value by using the blocking mechanism whenever the total user traffic overflows the network's bandwidth limitation. for the non-isochronous traffic the DMR-II protocol lets all the nodes to have fair transmission chances by using the reset mechanism based on the window counter scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.12B
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• pp.1042-1051
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• 2004

The IEEE1394 is a favorable protocol for A/V networks recently in home and there are two types of transmission in this protocol which are asynchronous and isochronous. The more nodes participate in the IEEE1394 network, the more problems of resource exhaustion and connection repetition may occur. So this paper proposes a middleware for isochronous connection management and reliable multimedia data transmission in the IEEE1394-IEC61883 based home networks. In this paper, proposed middleware is supporting the various types of isochronous connection, guaranteeing the reliability of isochronous connection and providing the characteristic of a real-time data transmission. We support CORBA API for multimedia service and the proposed architecture was implemented using a test-bed and we verified the proposed architecture in a test-bed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.4B
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• pp.217-226
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• 2007

By growth of digital media devices, a number of researches are in progress for transmission of isochronous traffic over network. Above all, network techniques that apply Ethernet, are in the limelight because of advantages of Ethernet. A standardization of network technique for isochronous traffic over Ethernet is in progress in IEEE 802.1 AVB TG. This paper proposed network technique for isochronous traffic over Ethernet model, that is, synchronous Ethernet model with synchronization method between devices. And this paper proposed bandwidth reservation method for transmission of isochronous traffic in synchronized devices. In this paper, synchronous Ethernet model is implemented through OPNET, efficiency of proposed methods is analyzed.

• Journal of the Korea Society of Computer and Information
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• v.8 no.3
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• pp.9-15
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• 2003

IEEE1394 standard supports both isochronous and asynchronous data transmission, thus enabling high-speed data exchange between PC and networked home electronic devices. This paper describes an implementation of Test Bed for Linux based IEEE1394 communication test. In this paper, An integrated Software was developed to test IEEE1394 communication environment. To develop the software, open source software(gscanbus,dvgrab, playdv, Xine, Kino) for the Linux environment was investigated and integrated. It was tested such as the communication among the devices, asynchronous date transmission, isochronous data transmission, and its result was successful. This integrated software has the potential to become efficient test tool for the futher development of networked home electronic devices and multimedia services.

• Journal of Korea Multimedia Society
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• v.7 no.1
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• pp.54-63
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• 2004

This paper describes a hybrid QoS guarantee scheme for high quality audio streaming services on the Internet. The continuous playback of the audio data requires the isochronous transmission of the audio data packet through the Internet. In order to retain the QoS at the ultimate destination (client) as the same as servers provide, the transmission protocols should consider the error conditions such as packet loss, and out of order delivery. Generally, the protocols supporting the transmission of continuous media data do not try to recover the errors. The protocols are working somehow for the toll quality multimedia streaming services, but rot for the high quality streaming services, such as the DVD sound/music payback. The hybrid QoS guarantee scheme includes the three mechanisms to overcome the problem. The selective retransmission for the lost packet, the adaptive buffering at client-side, and the adaptive transmission rate at server-side are totally adopted to recover the packet loss with the minimal overhead, to prevent from the buffer starvation during the retransmission, and to maintain the isochronous transmission even after the retransmission. The experiments have shown good results for the high Quality audio streaming services on the Internet.

• Journal of KIISE:Information Networking
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• v.30 no.4
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• pp.494-503
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• 2003

The IEEE 1394 High Speed Serial Bus is a versatile, high-performance, and low-cost method of promoting interoperability between all types of A/V and computing devices. IEEE 1394 provides two transfer modes: asynchronous mode for best effort service and isochronous mode for best effort service with bandwidth reservation. This paper shows the bus performance and compared the transfer odes first at the link level and then at the application level. For the application level performance, we analyze the bus systems with fixed and adaptive interfaces, applied between the upper layer and the 1394 layer, using polling systems. Also we verifies the analysis models with simulation studies. Based on our analysis, we conclude that the adaptive interface reduces the bus access time and so increases the bus utilization.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.2
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• pp.197-203
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• 2004

A real-time network in a distributed control system plays an important role for the reliable data transmission. Compared to the field-buses used in the past, TCP/IP protocol on the top of Ethered provides a compatibility between applications as well as an economical method to develop softwares. This paper proposes a modified TCP/IP structure for IEEE-1394 network, with which asynchronous and isochronous data transmission is selectively used for the real-time data transmission in a distributed control system. This paper also shows the performance of the proposed protocol by experiments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.9B
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• pp.838-847
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• 2006

In order to support multiple multimedia streaming services in home networks, many critical issues must be considered. In addition, handling the shortage of network bandwidth is one of the most significant and complicated issues. In this paper, real-time bandwidth management service is suggested as a solution to the problem regarding the IEEE1394-based home network. In order to handle the shortage of network bandwidth and to enhance the bus utilization rate, the proposed service combines two methods. First, the bus bandwidth management function determines the state of the network bandwidth and restores the residual bandwidth, which is excessively occupied by a streaming service, to the available free bandwidth. Second, the Isochronous Streaming (IS) Scheduler manages all streaming services according to priority. In order to test the proposed service, we implemented a prototype steaming management middleware and evaluated it by using the IEEE1394 network test-bed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.4C
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• pp.295-307
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• 2002

The IEEE 1394 protocol is a de facto standard in multimedia digital home network. It supports several advanced features such as hot plugging, dynamic network reconfiguration, isochronous transmission and so on. Since the IEEE 1394 was adapted in the field of multimedia service with QoS guarantee, back bone network protocol with reel-time digital instrumentation and control sub networks, and physical layer protocol for real-time middleware such as real-time CORBA, the additional real-time features has been required in device driver implementation because of the necessity of the predictability enhancement. To guarantee the real-time features, the device driver of the IEEE 1394 should support the priority based packet processing and also need a isochronous buffer management mechanism to deal with the periodic isochronous communication. In this paper, we proposed a new software architecture of the IEEE 1394 device driver for supporting the real-time characteristics such as priority based packet processing, priority based scheduling and so on.

• Journal of the Korea Society of Computer and Information
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• v.8 no.4
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• pp.47-56
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• 2003

According to rapidly developed mobile terminals and network in the play environment for multimedia presentation, different end-to-end QoS situations appear. Then the generation of transcoding path algorithm was reviewed to transcode a source'data satisfying the needed QoS from a destination and play it considering given transcoders and network. This method used only workload as a parameter although two parameters, workload and throughput, were needed to process multimedia stream in a transcoder, Therefore generated transcoding path with this method had additional calculation to check playability whether it was safisfed the QoS of a destination or not. To solve the problem this paper suggests T algorithm with evaluation function using isochronous property that is needed for multimedia stream to arrive a destination. That means, most playable path is selected with heuristic search based isochronous property between many transcoding paths. Using the suggested algorithm, a transcoding path can be generated faster to play the multimedia data with different end-to-end QoS in real-time transmission.