• Proceedings of the Korea Contents Association Conference
• /
• 2007.11a
• /
• pp.60-64
• /
• 2007

Increasing using multimedia services as VoIP, Video conference, DMB, IPTV, etc, it is necessary to increase network traffics and develop the mechanism about a flow control for real time traffic transmission. In order to transfer realtime multimedia data, the transfer rate can be control on network state data measuring packet losses of a receiver and delay time of packets through getting periodical feedback RTP/RTCP packet. This paper describes using efficiant flow control on multicast that can reduce errors according to getting feedback tranfer delay and proposes the mechanism that can adapt dynamic change of network. In simulation, the transfer rate can efficiently be control on dynamic change of network and it makes the maximum of the use of a bandwidth and the minimum of packet losses.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.10
• /
• pp.2150-2164
• /
• 1997

Two distinct features required in transport service and protocol to meet new multimedia applications requirements are multicast transmission capability and enhanced QoS facility. In this paper, we presents major functions and facilities of enhanced communications transport service definition supporting these requirements. At first, major fundamental issues, that should be handled to design multi-peer communcation service and protocol, are resoved and applied to design service definition. Secondly, we proposed several new functions for enhanced transport service such as heterogeneous TC establishment, invitation capability, TC-ownership transfer, restriction of transmit concurrency. The detils of proposed enhanced transport service are TC creation, TC invitation, TC join, multicase data transfer, pause of data transfer, resulme of data transfer, report of specific status, TC leave, TC termination, TC-ownership transfer, Token transfer services. The proposed transport service was submitted and accepted as a draft text for committee draft of international standard by the international standradization body such as JTC1/SC6 and ITU-T SG 7.

• The Transactions of the Korea Information Processing Society
• /
• v.2 no.1
• /
• pp.81-94
• /
• 1995

By intergrating technologies for protable computers, radio communications, and computer networking, the Land Mobile Computer Network(LMCN) is supposed to overcome the time and space limitation of present computer communication network. However, because the MHs(mobile hosts) do move any time, the network connectivity is often changed causing temporarily duplicated lost, or out-of-sequenced message delivery as well as frequent communications for maintainning the network connectivity. Previous works solved the problems through message flooding, used also in multicasting, resulting in high communication cost(i.e., number of communication messages). In this paper, new protocols for efficient mobility management and multicasting are proposed. The protocols define location update, handover, and multicasting procedure of a MH over a hierarchical LMCN architecture. The protocol specification is presented, and it is shown that the communication cost of the new protocols is superior to the existing ones in terms of the communication cost.

• The Journal of the Convergence on Culture Technology
• /
• v.4 no.1
• /
• pp.285-290
• /
• 2018

Vehicular ad hoc network (VANET) is one of the future communication technologies in which it offers safe-driving information and Internet access for both drivers and passengers by communicating among cars on the road. In case of applying Content Centric Network (CCN) rather than TCP/IP over VANET, called VCCN, it can provide efficient multicast communication of shared information among participating cars as well as offer corresponding one-to-one communications. This paper introduces SUMO for simulating traffic flows, VANET for car-to-car ad hoc communications, and CCN for a future Internet architecture. In addition, it compares and analyses the transmission performance of moving cars over VCCN. According to the simulation results using SUMO and VCCN, the larger the packet size, the better the transmission performance. In addition, VCCN provides higher packet transmission rate than that of TCP/IP when the clients shares the same contents. Furthermore, the overall data reception rate exceeds the physical transmission channel rate.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.1
• /
• pp.131-143
• /
• 1996

In this paper, we propose the improved structure of fully interconnected ATM Switch to develop the small sized switch element and represent practical implementation of switch network. As the part II of the full study about structure and implementation of fully interconnected ATM Switch, this paper especially describes the implementation of an ATM switching element with 8 input port and 8 output port at 155 Mbits/sec each. The single board switching element is used as a basic switching block in a small sized ATm switch for ATM LAN Hub and customer access node. This switch has dedicated bus in 12 bit width(8 bit data + 4 bit control signal) at each input and output port, bit addressing and cell filtering scheme. In this paper, we propose a practical switch architecture with fully interconnected buses to implement a small-sized switch and to provide multicast function withoutany difficulty. The design of switching element has become feasible using advanced CMOS technology and Embedded Gate Array technology. And, we also represent Application Specific Integrated Circuit(ASIC) of Switch Output Multiplexing Unit(SOMU) and 12 layered Printed Circuit Board for interconnection network of switch.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.8A
• /
• pp.625-632
• /
• 2009

This paper presents the mobile IPTV system for the transmission of FGS-encoded video stream over WiMAX network. The proposed system is implemented to provide more subscribers with an improved mobile IPTV service considering the scarce resource constraint. The proposed system pursues an efficient tradeoff between the number of subscribers that receive the enhancement layer stream and their IPTV service quality. In the proposed system, some parts of the enhancement layer are transmitted with the modulation scheme and the coding rate adaptive to wireless link states of subscribers. Finally, experimental results are provided to show the performance of proposed mobile IPTV system.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.10C
• /
• pp.956-963
• /
• 2006

This research studies multi participant consistency and dynamic data shared through 3D scenes in virtual network environments. In a distributed virtual environment of client-server structure, consistency is maintained by the static information exchange; as jerks occur by packet delay when updating messages of dynamic data exchanges are broadcasted frequence, the network bottleneck is reduced by predicting the movement path by using the Dead-reckoning algorithm. In Dynamic data path prediction, the tests the location prediction error between Dead-reckoning convergence interval and error of prediction and actual condition one time above threshold it interpolates a previously location. The shared dynamic data of the 3D virtual environment is implementation using the VRML EAI.

• Journal of Communications and Networks
• /
• v.15 no.2
• /
• pp.198-206
• /
• 2013

Recent advances in forward error correction (FEC) coding techniques were focused on addressing the challenges of multicast and broadcast delivery. However, FEC approaches can also be used for unicast content delivery in order to solve transmission control protocol issues found in wireless networks. In this paper, we exploit the error resilient properties of Raptor codes by proposing Raptor-based content delivery protocol (RCDP) - a novel solution for reliable and bidirectional unicast communication in lossy links that can improve content delivery in situations where the wireless network is the bottleneck. RCDP has been designed, validated, optimized, and its performance has been analyzed in terms of throughput and resource efficiency. Experimental results show that RCDP is a highly efficient solution for environments characterized by high delays and packet losses making it very suitable for intelligent transport system oriented applications since it achieves significant performance improvements when compared to traditional transport layer protocols.

• Journal of Satellite, Information and Communications
• /
• v.1 no.1
• /
• pp.40-47
• /
• 2006

The next-generation mobile communication system are required to provide high-data-rate and high quality transmission over hostile radio channels. Orthogonal Frequency Division Multiplexing(OFDM) technique regarded as a most promising solution in mobile environment. This paper considers the issue of efficient subcarrier allocation for OFDM system in multi-service application. Proposed algorithm can consider channel gain of each service and divide subchannel. Proposed method considers priority of service and divide more subchannels in high priority service. When proposed algorithm compares with existent algorithm, the convergence rate improves and the calculation amount is decreased.

• International Journal of Computer Science & Network Security
• /
• v.21 no.7
• /
• pp.341-349
• /
• 2021

Many emerging mobile ad-hoc network application communications are group-oriented. Multicast supports group-oriented applications efficiently, particularly in a mobile environment that has a limited bandwidth and limited power. Energy effectiveness along with safety are 2 key problem in MANET design. Within this paper, MANET is presented with a stable, energy-efficient clustering technique. In this proposed work advanced clustering in the networks with ticket ID cluster manager (TID-CMGR) has formed in MANET. The proposed routing scheme makes secure networking the shortest route possible. In this article, we propose a Cluster manager approach based on TICKET-ID to address energy consumption issues and reduce CH workload. TID-CMGR includes two mechanism including ticket ID controller, ticketing pool, route planning and other components. The CA (cluster agent) shall control and supervise the functions of nodes and inform to TID-CMGR. The CH conducts and transfers packets to the network nodes. As the CH energy level is depleted, CA elects the corresponding node with elevated energy values, and all new and old operations are simultaneously stored by CA at this time. A simulation trial for 20 to 100 nodes was performed to show the proposed scheme performance. The suggested approach is used to do experimental work using the NS- simulator. TIDCMGR is compared with TID BRM and PSO to calculate the utility of the work proposed. The assessment shows that the proposed TICKET-ID scheme achieves 90 percent more than other current systems.