• Convergence Security Journal
• /
• v.15 no.1
• /
• pp.83-89
• /
• 2015

In the wide area surveillance system including many CCTVs, application for remote realtime monitoring is designed and implemented. The applications using Xcode provide secure administrator interface from headquarters. Through the efficient and intuitive interface, it delivers real-time context reports and inference results. For the user convenience, it includes push alarm of events, SNS, Media streaming service for real-time monitoring uses Wirecast and Wowza media server. Wowza stream engine provides URL accommodating development specification. Mobile devices can receive real-time stream data. Performance evaluation in the processing is provided.

• International Journal of Contents
• /
• v.4 no.4
• /
• pp.12-17
• /
• 2008

The web 2.0 is leading a rapid change of internet services. The UCC(User Created Contents) service is one of the representative internet services with web 2.0 paradigm. In this paper, we design and implement the UCC services prototype system for image and video. The proposed system does not need to install ActiveX and client programs on devices of users to edit their contents. All processes for editing UCC are conducted on the server. Our proposed system consists of the two components such as the multimedia editing subsystem and the metadata management system. They provide the API to UCC service developers or vendors. The multimedia editing subsystem supports editing for image and video, and the streaming services of video. The metadata management subsystem supports the metadata management and retrieval of image and video.

• Journal of Digital Convergence
• /
• v.12 no.2
• /
• pp.335-341
• /
• 2014

To play the networked video contents in a client's mobile device in real time, the contents should be delivered to it by the contents server with streaming technology. Generally, in a server-client based commerce model, the server is in charge of both the authentication of the paid customer and distribution of the contents. The drawback of it is that if the customers' requests go on growing rapidly, the service quality would be degraded results from the problems of overloaded server or restricted network bandwidth. On the contrary, in P2P based networks, more and more the demand for service increasing, the service quality is upgraded since a customer can act as a server. But, in the P2P based network, there are too many servers to manage, it's possible to distribute illegal contents because the P2P protocol cannot control distributed servers. Thus, it's not suitable for commercial purposes. In this paper, the dymanic group authentication scheme is proposed which is suited to P2P based applications. The proposed scheme consists of group based key generation, key update, signature generation and verification protocols. It can control the seeder's state whether the seeder is joining or leaving the network, and it can be applied to hybrid P2P based commerce model where sales transactions are covered by the index server and the contents are distributed by the P2P protocol.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.2S
• /
• pp.721-732
• /
• 2000

Multimedia communication systems require not only high-performance computer hardwares and high-speed networks, but also a buffer management mechanism to process many data efficiently. Two buffer handling methods, Push and Pull, are commonly used. In the Push method, a server controls the flow of dat to a client, while in the Pull method, a client controls the flow of data from a server. Those buffering schemes can be applied to the data transfer between the packet receiving buffer, which receives media data from a network server, and media playout devices, which play the recived media data. However, the buffer management mechanism in client-sides mainly support either one of the Push or the Pull method. Consequently, they have some limitations to support various media playout devices. Futhermore, even though some of them support both methods, it is difficult to use since they can't provide a unified structure. To resolved these problems, in this paper, we propose an efficient and flexible Push/Pull buffer management mechanism at client-side. The proposed buffer management scheme supports both Push and Pull method to provide various media playout devices and to support buffering function to absorb network jitter. The proposed scheme can support the various media playback devices using a single buffer space which in consequence, saves memory space compared to the case that a client keeps tow types of buffers. Moreover, it facilitates the single buffer as a mechanism for the absorbing network jitter effectively and efficiently. The proposed scheme has been implemented in an existing multimedia communication system, so called ISSA (Integrated Streaming Service Architecture), and it shows a good performance result compared to the conventional buffering methods in multimedia communication environments.

• The KIPS Transactions:PartB
• /
• v.10B no.1
• /
• pp.87-94
• /
• 2003

A study on the characteristics of server workloads based on user access pattern offers insights for the strategies on continuous media caching and network workloads distribution. This paper analyses characteristics of continuous media filet in each fervor and user access requests to each of them, using log data of three commercial sites, which are providing continuous media files in the form of real time streaming on the Internet. These servers have more continuous files than ones in the previously reported studies and are processing very large number of user access requests. We analyse the characteristics of continuous media files in each server by the size of files. playback time and encoding bandwidth. We also analyse the characteristics of user access requests by the distribution of user requests to continuous media files, user access time, access rate based on the popularity of the files and the number if access requests to serial continuous media files.

• The Journal of Korean Institute of Next Generation Computing
• /
• v.15 no.4
• /
• pp.18-29
• /
• 2019

A dynamic adaptive streaming server consumes high processor power because it handles a large amount of transcoding operations at a time. For this purpose, multi-processor architecture is mandatory for which effective transcoding task distribution strategies are essential. In this paper, we present the design and implementation details of the transcoding workload distribution schemes at a 2-tier (frontend node and backend node) transcoding server. For this, we implemented four schemes: 1) allocation of transcoding tasks to appropriate back-end nodes, 2) task scheduling in the back-end node and 3) the communication between front-end and back-end nodes. Experiments were conducted to compare the estimated and the actual power consumption in a real testbed to verify the efficacy of the system. It also proved that the system can reduce the load on each node to optimize the power and time used for transcoding.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.3
• /
• pp.603-612
• /
• 2010

Recently, with the advance of computing and networking technique, the high speed internet becomes widespread, however, it is still hard job to do streaming the media which requires high network bandwidth over the internet. Previous VoD system researches for streaming over the internet mainly proposed techniques that controls the QoS(Quality of Service) of the media in proportion to the network status. Though, this could be the solution for the service provider while the service user who wants constant QoS may not satisfy with variable QoS. In the paper, we propose greedy precedent frame transmission technique, GPFT, for guarantee of constant QoS. In GPFT, Streaming VoD server prefetches precedent frames and transmits the frame greedily by increasing the frame transmission rate while the available network bandwidth is high. The GPFT uses the prefetched precedent frames to guarantee the QoS while the available network bandwidth is low. The experiment result shows that the proposed GPFT could guarantee the constant QoS by prefetching the frames adaptively to the network bandwidth with the characteristic of video stream.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.7B
• /
• pp.608-618
• /
• 2006

The increasing popularity of multimedia streaming services introduces new challenges in content distribution. Especially, it is important to provide the QoS guarantees as they are increasingly expected to support the multimedia applications. The service providers can improve the performance of multimedia streaming by caching the initial segment (prefix) of the popular streams at proxies near the requesting clients. The proxy can initiate transmission to the client while requesting the remainder of the stream from the server. In this paper, in order to apply the prefix caching service based on IETF's RTSP environment to the wireless networks, we propose the effective RTSP handling scheme that can adapt to the radio situation in wireless network and reduce the cutting phenomenon. Also, we propose the traffic based caching algorithm (TSLRU) to improve the performance of caching proxy. TSLRU classifies the traffic into three types, and improve the performance of caching proxy by reflecting the several elements such as traffic types, recency, frequency, object size when performing the replacement decision. In simulation, TSLRU and RTSP handling scheme performs better than the existing schemes in terms of byte hit rate, hit rate, startup latency, and throughput.

• KIPS Transactions on Computer and Communication Systems
• /
• v.10 no.2
• /
• pp.29-38
• /
• 2021

The Internet including mobile networks is developing to overcoming the limitation of physical distance and providing or acquiring information from remote locations. However, the systems that use video as primary information require higher bandwidth for recognizing the situation in remote places more accurately through high-quality video as well as lower latency for faster interaction between devices and users. The emergence of the 5th generation mobile network provides features such as high bandwidth and precise location recognition that were not experienced in previous-generation technologies. In addition, the Mobile Edge Computing that minimizes network latency in the mobile network requires a change in the traditional system architecture that was composed of the existing smart device and high availability server system. However, even with 5G and MEC, since there is a limit to overcome the mobile network state fluctuations only by enhancing the network infrastructure, this study proposes a high-definition video streaming system in ultra-low latency based on the SRT protocol that provides Forward Error Correction and Fast Retransmission. The proposed system shows how to deploy software components that are developed in consideration of the nature of 5G and MEC to achieve sub-1 second latency for 4K real-time video streaming. In the last of this paper, we analyze the most significant factor in the entire video transmission process to achieve the lowest possible latency.

• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.35C no.4
• /
• pp.60-68
• /
• 1998

In this paper, content addressable momory(CAM) using neural network algorithm is proposed to decrease cell loss and process the large amount of data in streaming mode connectionless server at high speed. To overcome problems of area and power dissipation in look-up table using conventional CAM, the proposed neural network CAM is designed to increase linearly address storage bit about increase of address input bit. Its design and imulation is performed by using VHDL and Compass Tool. Also, its layout is performed by using chip compiler, cell-base P&R tool of compass, in 0.8 .mu.m design rule environment.