• Journal of Korea Multimedia Society
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• v.8 no.9
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• pp.1208-1215
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• 2005

In the case of receiving feedbacks from many receivers in the multimedia application using multicasting, the traffic congestion caused bp heavy traffic results in the problem of transmission rate decrease. In solving of this, the local representative method is adopted. However, the control of transmission rate in consideration of all receivers caused uncongested local transmission rate to get slower. In this paper, there is a local representative in solving of this problem. When the transmission rate of a group is less than minimum support threshold, the local representative recounts the transmission rate without congested receivers. Therefore, The local representative method has improved the problem that the transmission rate of uncongested local decreases. The result of this paper shows that this method provides stable transmission rate rather than those of existing methods.

• Journal of Korea Multimedia Society
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• v.16 no.4
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• pp.464-471
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• 2013

With the advance of wireless sensor networks, WMSN(Wireless Multimedia Sensor Networks) researches to transfers multimedia data have been studied actively. First of all, three basic protocols, End-to-end, Hop-by-hop, and Unreliable transmission method, are compared to transfer multimedia data using simulations. This paper presents an efficient protocol to transfer multimedia data by overhearing messages of nodes and by transmitting next packets during the unused time interval. The proposed method is verified its performance by simulations and experiments. The results shows that the transmission rate of the proposed method 22% higher than that of End-to-end protocol with half of transmission time. Also the performance of the proposed method is compared with that of PIGAB(Packet Interval Gap based on Adaptive Backoff).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11C
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• pp.51-63
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• 2001

According to the popular use of the multimedia services in distributed environments, the need for the variable multimedia communication technologies have been presented today. In order to support the efficient transmission multimedia streams, the multicasting, and the interoperability between multimedia applications in distributed environments, the development of the open exclusive multimedia communication systems and the provision of the control and management methodologies for media streams have been required. In order support the realtime transmission of multimedia stream in distributed environments. the protocols such as RTP, RSVP, and RTSP have been standardized. For supporting the interoperability between multimedia applications and the control and management of streams, the distributed processing platforms such as CORBA by OMG and DSM-CC by DAVIC were published. In this paper, we introduce the CORBA-based distributed multimedia communication system which support the realtime transmission, control, and management of multimedia streams and provide the interoperability between multimedia applications. Finally, we present the QoS measurement results by the interoperability between our systems and VoD systems.

• Journal of Korea Multimedia Society
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• v.15 no.3
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• pp.356-363
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• 2012

Power Aware Routing Protocol of MANET(Mobile Ad-hoc Network) minimized the power consumption of each node and helped to extend the lifetime of the network. But due to the nature of the protocol, it tends to increase the transmission delay, so multimedia transmissions were difficult to be applied. In this paper, a delay-power aware routing protocol is proposed considering the delay transmission delay that can be applied to ad hoc network. The proposed protocol consider two conflicting index, transmission delay and power consumption at the same time, maintaining a certain level of delay transmission delay while minimizes the power consumption. It is observed from the simulation results compared to not-considering delay transmission delay that the proposed protocol decrease transmission delay by 30% while the power consumption less than 10% increase.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.1
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• pp.414-435
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• 2017

As network adaptive streaming technology becomes increasingly common, transport protocol also becomes important in guaranteeing the quality of multimedia streaming. At the same time, because of the appearance of high-quality video such as Ultra High Definition (UHD), preventing buffering as well as preserving high quality while deploying a streaming service becomes important. The Internet Engineering Task Force recently published Multipath TCP (MPTCP). MPTCP improves the maximum transmission rate by simultaneously transmitting data over different paths with multiple TCP subflows. However, MPTCP cannot preserve high quality, because the MPTCP subflows slowly increase the transmission rate, and upon detecting a packet loss, drastically halve the transmission rate. In this paper, we propose a new multipath congestion control scheme for high-quality multimedia streaming. The proposed scheme preserves high quality of video by adaptively adjusting the increasing parameter of subflows according to the network status. The proposed scheme also increases network efficiency by providing load balancing and stability, and by supporting fairness with single-flow congestion control schemes.

• Journal of Korea Multimedia Society
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• v.6 no.3
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• pp.488-495
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• 2003

With the development of networks, multimedia communication has expanded its application field. From the remote control for household electric appliances to medicine, games, video conferencing and multimedia chatting, multimedia communication is being used in all parts of our lives. This multimedia communication requires the transmission of a lot of data at high speed. But if the transmission rate of the communication network exceeds the processing speed of being used in the high speed network environment, a bottleneck occurs in each node and deteriorates the performance of the network. This is the main reason for the slow speed of data transmission and packet loss. In this paper, considering the client's processing performance, reception performance was predicted and the way of flow control was shown. The computing performance of relevant Processor and its performance was estimated through the actual implementation.

• IEIE Transactions on Smart Processing and Computing
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• v.1 no.3
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• pp.182-191
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• 2012

This paper proposes a high performance QoS (Quality of Service) traffic transmission scheme to provide real-time multimedia services in wireless networks. This scheme is based on both a traffic estimation of the mean rate and a header compression method by dividing this network model into two parts, core RTP/UDP/IP network and wireless access parts, using the IEEE 802.11 WLAN. The improvement achieved by the scheme means that it can be designed to include a means of provisioning the high performance QoS strategy according to the requirements of each particular traffic flow by adapting the header compression for real-time multimedia data. A performance evaluation was carried out to show the effectiveness of the proposed traffic transmission scheme.

• ETRI Journal
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• v.28 no.3
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• pp.364-366
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• 2006

This letter introduces an efficient transmission of traffic information through a terrestrial digital multimedia broadcasting system, which is a multimedia and mobility empowered option of the European digital audio broadcasting system. By adapting Korean characteristic traffic information into the transport protocol expert group messages in the traffic information delivery, a highly efficient traffic information system was implemented and tested in Korea.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.1
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• pp.183-195
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• 2014

Multicasting is an efficient way of group communications because one sender can transmit data to multiple receivers with only one transmission. Furthermore, multicasting is considered an appropriate transmission method for multimedia services. Multimedia applications are expected to become more prevalent over mobile ad-hoc networks in the near future. Therefore, achieving reliability in multimedia communications is an important task. In this paper, we propose a leader-based reliable multicast medium access control layer protocol for multimedia applications to enhance video quality. We present a Markov chain model and numerical formulation of our proposed system.

• Journal of Korea Multimedia Society
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• v.2 no.1
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• pp.59-68
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• 1999

Multimedia applications have an ability to transmit a lot of data in real time. In mobile circumstances the replay of continuous multimedia data in real time causes frequent replay breaks and poor service quality because of low transmission speed and new transmission path settings in hand-off. To avoid these unfavorable side effects, we need a new mechanism which can transmit data efficiently between base station and mobile hosts, to control the buffers of mobile hosts, and to switch to a new transmission path rapidly in hand-off. The study is to propose how to give good service to mobile hosts during hand-off and the mechanism which can increase the number of mobile hosts in the cell unit.