• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.49 no.6
• /
• pp.9-17
• /
• 2012

High-quality multimedia on the Internet has attracted attention because of its wide application area. IP multicast has been proposed as a solution to use efficient network resources in these services. However, IP multicast has not been commonly used due to a number of practical issues such as security and management. As an alternative, an overlay multicast routing which is performed in upper protocol layers on legacy networks without changing hardware has been presented. Yet, the maximum data transmission capacity of the overlay multicast is not sufficient for real time transmission of multimedia data. In this paper, we have implemented an overlay multicast engine on NetFPGA which allows us to perform packet replication and tunneling which need high-speed. In addition, we have implemented extra portions which need low-speed in software. From now on, we will progress research which increase the number of terminal spots which can be replicated by improvement and amplify throughputs by optimization.

• Journal of KIISE:Information Networking
• /
• v.34 no.4
• /
• pp.239-245
• /
• 2007

New multimedia services over the cellular/WLAN overlay networks require different Quality of Service (QoS). In the cellular/WLAN overlay structure, the main issue of load balancing is to balance the available bandwidth among different networks. In this paper, we propose a new online network management scheme. Our proposed scheme is designed to improve bandwidth utilization by balancing the traffic load between the cellular network and WLANs. Simulation results indicate the superior performance of our proposed framework to strike the appropriate performance balance between contradictory QoS requirements under widely varying diverse traffic loads.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.1B
• /
• pp.27-38
• /
• 2005

IP Multicast has not been deployed because of hardware problems. So a new scheme that is called Overlay Multicast for group communication has been emerged. It supports IP Multicast functions, which is located on application level. For developing it, we have been focused on efficient overlay tree construction among group members with low stretch and stress. However, we should consider a variety of transmission or receipt condition since a real internet environment has users with various transmission/receipt rates. Thus, we make one-time source specific tree depending on required bandwidth informationof group members when a member requests data transmission. Our mechanism provides satisfied data quality limited maximum transmission rate of the source to each group members. Furthermore, we manage a large group enough as distributing control information to cores that are designated membersfor maintaining host member information. Lastly, we prove that our tree guarantees data quality to each group members, and show low tree consruction time is required. In addition, for evaluating group scalability, we analyze control information increasing rate via group size, and validate its scalability.

• Journal of Digital Convergence
• /
• v.19 no.4
• /
• pp.151-157
• /
• 2021

Recently, IoT technology has been applied to various cloud environments, requiring accurate verification of various information generated by IoT devices. However, due to the convergence of IoT technologies and 5G technologies, accurate analysis is required as IoT information processing is rapidly processed. This paper proposes a blockchain-based multi-IoT verification model for overlay cloud environments. The proposed model multi-processes IoT information by further classifying IoT information two layers (layer and layer) into bits' blockchain to minimize the bottleneck of overlay networks while ensuring the integrity of information sent and received from embedded IoT devices within local IoT groups. Furthermore, the proposed model allows the layer to contain the weight information, allowing IoT information to be easily processed by the server. In particular, transmission and reception information between IoT devices facilitates server access by distributing IoT information from bits into blockchain to minimize bottlenecks in overlay networks and then weighting IoT information.

• The Journal of the Korea Contents Association
• /
• v.9 no.12
• /
• pp.528-536
• /
• 2009

Recently, the importance of IPTV providing multimedia service over IP based networks managed to provide the required level of quality of service and experience, security, interactivity and reliability has been gradually increasing by the commercialization of its service. However, the original purposes of IPTV service - contents are produced and consumed anytime, anywhere, and over any device at the same time - have not been satisfied by service providers because most services offered by service providers depend on closed IPTV platform. In this paper, we propose an open IPTV service platform that an individual or small company can easily produce contents and offer IPTV service independently from the existing closed IPTV platform.. The proposed IPTV platform exploits overlay multicast scheme to offer reasonable service under the environment where network bandwidth and processor resource are limited. It also uses CDN-like scheme to ensure the quality of transmitted contents. The performance evaluation shows that the proposed IPTV platform has the possibility of being an open IPTV platform considering its results such as the quality of transmitted contents, the transmission rate, the channel zapping time, and so on. It also shows that proposed IPTV platform could be applied to real IPTV service with continuous enhancement of its functions and user interfaces.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.1
• /
• pp.85-91
• /
• 2013

Recently, the weight of high-quality multimedia contents is explosively growing out of the network total traffic. This steep increase of media contents to require huge traffic does not contribute to the generation of revenue streams and it leads to the situation of dumb pipe to trouble network providers into the big burden of investment on the network expansion. Accordingly, the transfer to the smart network to enable the effective delivery of large-scale media is imminently challenging issue to the network providers to seek the profitable business. The smart network revolves around the technologies to enhance end-to-end quality and fair usage with network resources and to optimize the traffic for the contents delivery over the concept of Content-Centric Network. In this paper, we propose an architecture and fundamental functions suitable for the smart network and suggest improved test results through the construction of an experimental network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2006.05a
• /
• pp.538-541
• /
• 2006

Recently researches of P2P media streaming have been actively published, but the research what kind of P2P overlay networks are better to delivering media data has not been attended. This paper designs a P2P streaming media system model. In this system, we constructs a Half-Structure P2P overlay protocol based on node's capability as the infrastructure of streaming application, which utilizes the heterogeneity of the nodes to maintain topology, presents a active contents diffusing algorithm and Two-stage search algorithm, make it possible for nodes in P2P system to collect information according their capacity and reduces the number of forwarding packet compared with flooding. Also, we give an optimal scheme to scheduling media data.

• Journal of KIISE:Computing Practices and Letters
• /
• v.13 no.3
• /
• pp.153-164
• /
• 2007

The Access Grid (AG) provides collaboration environments over the IP multicast networks by enabling efficient exchange of multimedia contents among remote users; however, since lots of current networks are still multicast-disabled, it is not easy to deploy this multicast-based multi-party AG. For this problem, the AG provides multicast bridges as a solution by putting a relay server into the multicast networks. Multicast-disabled clients make UDP connections with this relay server and receive forwarded multicast traffics in unicast UDP packets. This solution is facing several limitations since it requires duplicate forwarding of the same packet for each unicast peer. Thus, in this paper, we propose an alternate solution for the multicast connectivity problem of the AG based on the UMTP (UDP multicast tunneling protocol). By taking advantage of flexibilities of UMTP, the proposed solution is designed to improve the efficiency of network and system utilization, to allow reuse of multicast-based AG applications without modification, and to partially address the NAT/firewall traversal issues. To verify the feasibility of proposed solution, we have implemented a prototype AG connectivity tool based on the UMTP, named as the AG Connector.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2008.11a
• /
• pp.1348-1351
• /
• 2008

최근 인터넷 사용자들의 요구는 멀티미디어로 집중되고 있으며 그중 라이브 미디어 스트리밍 서비스에 대한 요구가 증가하고 있다. 라이브 서비스에서는 적절한 시간에 사용자에게 데이터가 도착하는 것이 중요하다. 따라서 라이브의 시간적절성을 충족시켜 줄 효율적이고 신속한 데이터 전달구조와 전송기법이 요구된다. 이에 본 논문에서는 트리와 메시 구조를 혼합한 하이브리드 방식으로 네트워크 자원을 효율적으로 사용하면서 빠른 데이터 전송으로 라이브의 시간적절성을 충족시킬 수 있는 데이터 분할 전송 방식의 P2P(Peer-to-Peer) 오버레이 구조를 제안한다. 제안하는 ToG(Tree of Groups)는 n개의 피어들이 메시로 그룹을 형성하고, 그렇게 형성된 그룹들이 트리를 이루는 구조이다. ToG에서 그룹 내의 각 피어들은 상위그룹의 피어 한 개와 부모-자식으로 연결되어 있어서 그룹 사이에 여러 개의 연결이 존재하게 된다. 따라서 그룹 내에서 어느 한 피어가 그룹을 빠져 나가더라도 상위그룹과의 여러 연결에 의해서 서비스 지속성을 보장 할 수 있다. ToG는 그룹단위로 트리가 형성되기 때문에 피어의 개수가 같을 때 피어단위로 트리를 형성하는 구조보다 트리의 깊이가 줄어든다. 그에 따라 말단에 있는 피어들에게까지 빠른 시간에 데이터가 전달 될 수 있다. ToG의 데이터 전달은 소스로부터 세그먼트가 일정한 값 n으로 나뉘어져 각 피어들에게 전달된다. 세그먼트 조각은 소스로부터 나뉘어져 전송 될 때 책임적으로 전달해야할 피어와 전달 순서가 정해져있고, 데이터 전송 스케줄링을 위한 버퍼 맵 교환은 필요하지 않다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.7
• /
• pp.879-884
• /
• 2020

In the conventional video file system, videos are stored in a high performance server which has mass storage hard disks or disk arrays. For 3D internet broadcasting, real time operations are required to transmit video files to many clients. This paper describes the design of the 3D internet broadcasting system which can provide realtime streaming service to many users in the 5G environment. In reality, unicast is used to transmit multimedia contents over the internet rather than IP multicast since IP multicast has its own drawbacks in deployment, security, maintenance and so on. In addition, multimedia broadcasting service system like VoD has difficulties in applying to 3D internet broadcasting system since it requires a large amount of system and network resources. In this work, we develop a 3D internet broadcasting system which can construct effective data delivery by minimizing performance-degrading factors.