• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.10B
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• pp.857-865
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• 2004

Recently the interest in digital home services and its related technology has increased rapidly. Multimedia data transmission between digital devices that are connected to home network is essential function. This paper presents the design and implementation of multimedia streaming system based on IEEE1394 in Linux environment. The key features of proposed system are as follows. First, it can transmit and receive not only DV format data but also MPEG2-TS format data through IEEE1394 bus. Second, it uses device drivers that handling IEEE1394 and IEC61883 protocol transparently to reduce the complexity of communication program. Third, it applied capacity adaptation technique considering various specifications of PCs to get smooth streaming for HD data. These characteristics are tested on testbed of IEEE1394 based home network. The proposed media streaming technique can be used as a home media sever in Linux environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.506-515
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• 2015

In this paper, we propose a group playback synchronization method using adaptive synchronization delay time by the bit rate of media to synchronize a play position of streaming media between mobile smart devices. This method consists of streaming server-side and client-side synchronization algorithms based on synchronization delay time which includes connection time, control packet transmission time, streaming data buffering time, and synchronization processing time. We implement the Android media player application with synchronization support using the proposed algorithms and present the result of performance evaluation.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.3
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• pp.117-124
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• 2013

In this paper we propose a TFRC(TCP Friendly Rate Control) which guarantees a minimum rate in order to improve the efficiency of the previous TFRC which cannot distinguish congestion losses and wireless losses and decreases throughput both in wired and wireless networks. This TFRC technique is able to guarantee a minimum rate for video by restricting a loss event rate with packet loss probability about existing TFRC and constraining a rate reduction from the feedback timeout. When we experimented both the existing TFRC and the new one with TCP in the same network, we found that the latter is better than the former. Consequently, it shows that the proposed TFRC can improve video streaming quality using a guaranteed minimum transmission rate.

• The Journal of the Korea Contents Association
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• v.8 no.10
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• pp.20-26
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• 2008

The quality of stream remaking is decided the load of a server and Jitter through the traffic of the transmission path between end to end. In order to improve these problems in this paper, I propose tree construction method of low-delay-level-multicast. In this case which the network congestion will be occurred by streaming quality, I also propose the technique which dynamically changes the transmission path. This technique first constructs the overlay structure for relaxing the overload of server. Secondly, in order to decrease Jitter of client, it makes upload bandwidth and low latency balanced. In the evaluation of the performance, this paper showed better enhancement of about $15%{\sim}24%$ than P2CAST[4] in the simulation about node average join count, average bandwidth, service request refusal ratio, RTT measurement of nodes, and node average join count by defect ratio.

• Journal of IKEEE
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• v.9 no.2 s.17
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• pp.170-178
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• 2005

The video data corrupted by the transmission error due to packet loss induce error propagation in decoded video data, and cause poor video quality. To remedy these corrupted video data, there have been introduced two types of error concealment techniques: spatial or temporal error concealment algorithm. Computational overhead by using spatial error concealment algorithm is a serious disadvantage in mobile video data streaming environment. In this paper, we propose hybrid type error concealment technique recovering video quality of mobile device using MPEG-4 video streaming on error-prone wireless network. Our algorithm is implemented in MPEG-4 decoder. The algorithm adopts Intel Wireless MMX technology to provide high performance of portable embedded multimedia mobile device. It is proven that the proposed algorithm shows expected performance for a mobile streaming system(PDA) on IP channels. Our approach showed better processing speed and better video quality comparing with traditional error concealment algorithm.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.81-88
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• 2012

As the performance of the next-generation broadband wireless networks is dramatically enhanced, various services (i.e., education, Live video streaming, Live video conferencing, online games, etc.) have been provided to users through a smart mobile platform. Those services are usually provided by using the centralized communication server. However, since all multimedia traffic is exchanged through a communication server, it often has the scalability problem with regard to traffic management. Our main purpose is for group smart users to provide scalable live multimedia streaming service based on P2P network. To do this, we have designed an architecture of P2P-based service management for mobile group communication management and service management protocol. In order to verify the performance of the proposed scheme, we have mathematically analyzed the performance in terms of the average transmission delay and bandwid th utilization.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.4
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• pp.371-380
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• 2020

Video is principal information that facilitates commander's immediate command decision. Due to fading characteristics of radio link, however, it is difficult to stably transmit video in a multi-hop wireless environment. In this paper, we propose a MANET structure composed of a link adaptive routing protocol and a TDMA MAC protocol to stably transmit video traffic in a ultra-narrowband video streaming network. The routing protocol can adapt to link state change and select a stable route. The TDMA protocol enables collision-free video transmission to a destination using multi-hop dynamic resource allocation. As a result of simulation, the proposed MANET structure shows better video transmission performance than proposed MANET structure without link quality adaption, AODV with CSMA/CA, and OLSR with CSMA/CA structures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1621-1630
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• 2009

There is a lot of recent research to provide services of dynamic distributed contents in P2P-based distributed environment. Distributed services of contents objects, however, have problems in QoS and dynamic management of segments. This paper proposed a new segment management method for the service of P2P-based distributed contents. The proposed method manages groups by the SGM(Segment Group Manager). The SGM manages streaming efficiently by the grouping of segments to be served in P2P environment. The segments in the same group cooperate for improved QoS using the management structure based on the distance and relationship. The distance-based management structure is for the improvement of retrieval efficiency while the relationship-based management structure is for the improvement of service ratio. The simulation results of the proposed method showed improvements in average transmission efficiency and average service rate. The improvement is 8% - 30% in average transmission efficiency and 10% - 30% in average service rate.

• Journal of Broadcast Engineering
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• v.25 no.4
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• pp.560-568
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• 2020

In recent years, as network technology develops, the usage of streaming services by users is increasing. However, the complexity of streaming services is also increasing due to various terminal environments. Even when streaming the same content, it is necessary to re-encode the content according to the type of service. In order to solve the complexity and latency of the streaming service, Moving Picture Experts Group (MPEG) has standardized the Common Media Application Format (CMAF). In addition, as content transmission using a communication network becomes possible, the Republic of Korea's Ultra High Definition (UHD) broadcasting standard has been enacted as a hybrid standard using a broadcasting network and a communication network. The hybrid service enables various services such as transmitting additional information of contents or providing user-customized contents through a communication network. The Republic of Korea's UHD transmission standard utilizes MPEG Media Transport (MMT), and Mobile MMT is an extension of MMT to provide mobile network-specific functions. This paper proposes a method of inserting CMAF contents suitable for various streaming services using signaling messages of MMT and Mobile MMT. In addition, this paper proposes a model for content insertion system in heterogeneous network environment using broadcasting and communication networks, and verifies the validity of the proposed technology by checking the result of content insertion.

• Journal of Information Processing Systems
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• v.19 no.6
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• pp.817-829
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• 2023

Variable wireless channel is a big challenge for real-time video applications, and the rate adaptation of realtime video streaming becomes a hot topic. Intra-video coding is important for high-quality video communication and industrial video applications. In this paper, we proposed a novel adaptive scheme for real-time video transmission with intra-only coding over a wireless network. The key idea of this scheme is to estimate the instantaneous remaining capacity of the network to adjust the quality of the next several video frames, which not only can keep low queuing delay and ensure video quality, but also can respond to bandwidth changes quickly. We compare our scheme with three different schemes in the video transmission system. The experimental results show that our scheme has higher bandwidth utilization and faster bandwidth change response, while maintaining low queuing delay.