• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.9
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• pp.4572-4586
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• 2019

Mobile Edge Computing (MEC) and Information-Centric Networking (ICN) are essential network architectures for the future Internet. The advantages of MEC and ICN such as computation and storage capabilities at the edge of the network, in-network caching and named-data communication paradigm can greatly improve the quality of video streaming applications. However, the packet loss in wireless network environments still affects the video streaming performance and the existing loss recovery approaches in ICN does not exploit the capabilities of MEC. This paper proposes a Deep Learning based Loss Recovery Mechanism (DL-LRM) for video streaming over MEC based ICN. Different with existing approaches, the Forward Error Correction (FEC) packets are generated at the edge of the network, which dramatically reduces the workload of core network and backhaul. By monitoring network states, our proposed DL-LRM controls the FEC request rate by deep reinforcement learning algorithm. Considering the characteristics of video streaming and MEC, in this paper we develop content caching detection and fast retransmission algorithm to effectively utilize resources of MEC. Experimental results demonstrate that the DL-LRM is able to adaptively adjust and control the FEC request rate and achieve better video quality than the existing approaches.

• Journal of Korea Multimedia Society
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• v.12 no.7
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• pp.913-921
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• 2009

Quantization is an essential method for compression of video. The quantizer can adjust the bitrate and control the picture quality. Especially, the subjective picture quality can be improved if the concerned region within a video sequence has good picture quality. In this paper, firstly a classification method according to the subjective concerned region within the video sequence is suggested. Also we propose a method that assigns the quantization step-size differentially according to the concerned region within the video. Totally subjective picture quality can be increased by appling the quantization step-size as small value relatively for the concerned region compared with the other regions. We can find the result that the proposed method gives the improved picture quality by assigning differently quantization step-size and the best improvement can be brought when the difference between maximum and minimum values of the quantization step-size in a picture is from 4 to 8.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.931-936
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• 2006

This paper presents different issues of the real-time compression algorithms without compromising the video quality in the distributed environment. The theme of this research is to manage the critical processing stages (speed, information lost, redundancy, distortion) having better encoded ratio, without the fluctuation of quantization scale by using IP configuration. In this paper, different techniques such as distortion measure with searching method cover the block phenomenon with motion estimation process while passing technique and floating measurement is configured by discrete cosine transform (DCT) to reduce computational complexity which is implemented in this video codec. While delay of bits in encoded buffer side especially in real-time state is being controlled to produce the video with high quality and maintenance a low buffering delay. Our results show the performance accuracy gain with better achievement in all the above processes in an encouraging mode.

• The Transactions of the Korea Information Processing Society
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• v.7 no.12
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• pp.3794-3803
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• 2000

In a Video-on-Demand system, admission control that is used to serve multimedia data efficiently has to be perfonned by an accurate grasp of the condition of surplus resources. Most of all. we need to adaptable admission control mechanism because the disk has irregular response time caused by external elements of disk, and also has high deviation of amount demanded. In previous admission control schemes, they determined whether a new user is granted or not through a theoretical value. Although they based on the measurement, they left much to be desired in dealing with the service state. Measurement ~based statistical admission control scheme, as we su~~ested in this research, perfonns 2 processes of off-line process and on-line process in real service environment. Through this processes, we can grasp the accurate resource state of system and adaptive!y detennine the admission according to circumstances. Therefore, it can guarantee both maximum resource utilization and QoS(Quality of Service). On performance evaluations, we show that the video server can utilize maximum resource utilization with QoS guarantee through precision of perfonnance by measurement and adaptable admission control according to the requested bandwidth.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.6
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• pp.1152-1168
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• 2010

Recently, due to the prevalence of various mobile devices and wireless broadband networks, there has been a significant increase in interest and demand for multimedia streaming services such as the mobile IPTV. In such a wireless broadband network, transmitting a continuous stream of multimedia data is difficult to achieve due to mobile stations (MSs) movement. Providing Quality of Service (QoS) for multimedia video streaming applications requires the server and/or client to be network-aware and adaptive. Therefore, in order to deploy a mobile IPTV service in wireless broadband networks, offering users efficient wireless resource utilization and seamlessly offering user perceived QoS are important issues. In this paper, we propose a new adaptive streaming scheme, called MARC (Mobile-aware Adaptive Rate Control), which adjusts the quality of bit-stream and transmission rate of video streaming based on the wireless channel status and network status. The proposed scheme can control the rate of multimedia streaming to be suitable for the wireless channel status by using awareness information of the wireless channel quality and the mobile station location. The proposed scheme can provide a seamless multimedia playback service in wireless broadband networks in addition to improving the QoS of multimedia streaming services. The proposed MARC scheme alleviates the discontinuity of multimedia playback and allocates a suitable client buffer to the wireless broadband network. The simulation results demonstrate the effectiveness of our proposed scheme.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.635-637
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• 1999

기존의 인터넷 기반 데이터 서비스는 'Best-effort' 정책으로 멀티미디어 서비스를 위한 트래픽 제어(traffic control) 기능을 제공하지 못한다. 그러므로 실시간 데이터 전송을 기반으로 제공되는 VOD(Video-on-Demand) 서비스는 사용자가 원하는 QoS(Quality of Service)를 제공할 수 없다. 따라서 인터넷 상에서 트래픽 제어 기능을 갖춘 중개자를 두어 VOD 서비스를 제공하는 방법에 대해 제안한다. 중개자의 주요 기능은 비디오 서버와 클라이언트 사이에 비디오 데이터의 버퍼링 기능을 이용하여 실시간 트래픽 제어를 수행한다. 이런 기능을 가진 중개자를 에이전트라 부르고, 에이전트에 대한 설계 및 구현에 대해 기술한다.

• Journal of Advanced Navigation Technology
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• v.18 no.1
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• pp.67-73
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• 2014

Due to the development of the communication technology and the high-performance mobile device, the number of video streaming service user has been increasing. Video streaming services in the restricted network environments need error control to support users for the Ultra High Definition(UHD) video delivery. Packet-level FEC method was used to control the error for delay-sensitive video service, but it has a defect in huge occupation of network resources by redundant packets. In this paper, we proposed a packet-level FEC algorithm which maintains the video quality by previous FEC methods and also reduces the occupation of network resource in the restricted network environments. The proposed algorithm controls the redundant rate with using the delivery characteristic of the video coding technology, and improves the efficiency of network resources by reducing the traffic by around 33% in comparison with the previous FEC methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9A
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• pp.1285-1294
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• 1999

In this paper we consider the performance of TCP video traffic over ABR with Long-Range Dependent VBR traffic. As compressed coded video traffics are increasing rapidly over Internet, lots of studies are being done for transmitting those traffics efficiently using limited network resources. We consider here the transmitting video service over ABR service in ATM networks, especially satellite networks. CBR or VBR services are suggested in transmitting the video traffic in ATM Forum TM 4.0. But ABR service connection, which is considered as appropriate service for data traffic, can be established with a small amount of bandwidth, MCR (Minimum cell rate). Furthermore ABR service can control the source's transmitting rate using feedback mechanism. Using this feature ABR service can be used in some applications which can control their quality of services corresponding to network loads. Compressed video sources with MPEG-2 are used for Long-Range Dependent VBR traffic here. We model the compressed video source to resemble the MPEG-2 transport streams. These compressed video traffic streams are consisted of three different frames, I-frame, P-frame, and B-frame. So when a network are overloaded, we can control the quality of service using this traffic features. TCP Traffics over ABR need large buffers in ATM switch to satisfy their QoS with background VBR traffics, which have high deviations in bandwidth. Furthermore satellite ATM networks with large feedback delay need large buffers corresponding RTT delay. The performance comparisons among EFCI and ER switch (ERICA+) switches in the network circumstances described above were shown in this paper. We also considered the case with ON-OFF VBR traffics.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.12C
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• pp.1209-1216
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• 2003

The transcoding is needed to modify the bit rate of the video bitstream in accordance with the bandwidth of a variety of channels in order to provide users with a realtime multimedia service and more stable and credible VOD(Video On Demand) service on various wire/wireless network. This paper suggests how to guarantee the video quality in the transcoding process, taking the activity and direction of the macroblock into consideration, thereby reducing the calculation. The threshold of the macroblock's activity and direction is applicable to the different videos, with the DCT coefficients from the intermediate data in the decoding process. Moreover, the suggested video transcoding algorism enables us to maintain the proper video quality and reduce the calculation through the video bit rate change experiment in H.263 environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.2B
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• pp.110-119
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• 2012

In this paper, we propose an efficient video streaming system over heterogeneous wireless networks. The proposed system modifies fountain code for the video streaming service and maximizes the target video encoding rate using multiple paths while satisfying delay and block recovery failure rate constraints of fountain code. Finally, the proposed system provides the seamless video streaming service of high quality to subscribers by dynamic adaptation of control parameters based on the states of each path over heterogeneous wireless networks.