• Journal of IKEEE
• /
• v.7 no.2 s.13
• /
• pp.288-298
• /
• 2003

We consider a window-controlled selective-repeat ARQ scheme for error control between two adjacent nodes lying on a communication path. In this scheme, each packet to be transmitted is endowed with a serial number in a cyclic and sequential fashion. In turn, the transmitting node is not allowed to transmit a packet belonging to a window before every packet in the previous window is positively acknowledged. Such postponement of packet transmission incurs a degradation in throughput and delay performance. In this paper, aiming at improving packet delay performance, we employs a supplement scheme in which a serial number is duplicated within a frame. Classifying duplication rules into fixed, random and adaptive categories, we present candidate rules in each category and evaluate the packet delay performance induced by each duplication rule. From numerical examples, we observe that duplicating serial numbers, especially ADR-T2 effectively reduces mean packet delay for the forward channel characterized by a low packet error rate. We also reveal that such delay enhancement is achieved by a high probability of hitting local optimal window size.

• Proceedings of the Korean Information Science Society Conference
• /
• 2011.06a
• /
• pp.420-421
• /
• 2011

This paper derive an optimal distributed power control strategy under both the probability of dropping a packet due to buffer overflow constraints at the secondary users and the interference constraints to the primary users.

• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.10
• /
• pp.1013-1017
• /
• 2010

This paper proposes a systematic approach to the rate-based feedback control based on the supervisory control framework for discrete event systems. We design the supervisor to achieve the desired behavior for TCP wireless networks. From the analysis and simulation results, it is shown that the controlled networks guarantee the fair sharing of the available bandwidth and avoid the packet loss caused by the buffer overflow of TCP wireless networks.

• ETRI Journal
• /
• v.26 no.6
• /
• pp.653-656
• /
• 2004

This paper presents an effective algorithm for inserting an MPEG-2 transport stream (TS) into a Digital Audio Broadcasting (DAB) ensemble without any bandwidth waste in a Digital Multimedia Broadcasting (DMB) transmission system. The key technologies of this algorithm include packet rate control and program clock reference correction, which are important for TS processing. The proposed algorithms are applied to the various DMB transmission systems based on Eureka-147, and the performance of the proposed algorithm is confirmed through the experimental DMB broadcasting.

• Proceedings of the KIEE Conference
• /
• 2004.11c
• /
• pp.231-233
• /
• 2004

Queuing is waiting lines which play routing service when packet entered. Queuing is decide how and whom is going to provide priority service. This is kind of first in first out(FIFO) or weighted fair queuing(WFQ) method. In this study, UDP design using WFQ way to serve to provide service evenly and rapidly in network. Also in actuality internet, datagram analyzed by packet captured. Queuing services through the requesting port number, input, output, output queuing creation & delete, message request by internet control message protocol(ICMP). Queuing designed in control block module, input queues, input/output module composition. In conclusion, I have confirm queuing result of WFQ method by the datagram information analyzed.

• Proceedings of the IEEK Conference
• /
• 2003.07d
• /
• pp.1629-1632
• /
• 2003

Generally an increasing number of recent applications have found TCP too limiting. There are some characteristics in the transmission of document and binary data which some transmission delay are tolerant but the content must completely be transferred. However voice signals are more sensitive with not some packet loss but some transmission delay. Therefore, Stream Control Transmission Protocol(SCTP) is proposed to minimize the delay and packet loss in the field of delivery of voice signal. SCTP is designed to transport PSTN signalling messages over IP networks, but is capable of broader applications. In this paper, the architecture of SCTP implementation is designed and some interface of SCTP software library which are implemented are specified.

• Journal of KIISE:Information Networking
• /
• v.29 no.5
• /
• pp.495-500
• /
• 2002

We propose a new estimation method for rate adjustment in the face of a packet loss in the TFRC protocol, a TCP-Friendly congestion control protocol for UDP flows. Previous methods respond in a sensitive way to a single packet loss, resulting in oscillatory transmission behavior. This is an undesirable for multimedia services demanding constant bandwidth. The proposed TFRC provides more smooth and fair (against TCP flows) transmission through collective response based on multiple packets loss events. We show our "Exponential smoothing method" performs better than known "Weight smoothing method" in terms of smoothness and fairness.

• ETRI Journal
• /
• v.28 no.6
• /
• pp.709-720
• /
• 2006

In this paper, we suggest a simple and efficient multiple-forwarder-based file distribution method which can work with a tree-based application layer multicast. Existing multiple-forwarder approaches require high control overhead. The proposed method exploits the assumption that receivers join a session at different times. In tree-based application layer multicast, a set of data packets is delivered from its parent after a receiver has joined but before the next receiver joins without overlapping that of other receivers. The proposed method selects forwarders from among the preceding receivers and the forwarder forwards data packets from the non-overlapping data packet set. Three variations of forwarder selection algorithms are proposed. The impact of the proposed algorithms is evaluated using numerical analysis. A performance evaluation using PlanetLab, a global area overlay testbed, shows that the proposed method enhances throughput while maintaining the data packet duplication ratio and control overhead significantly lower than the existing method, Bullet.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.8
• /
• pp.19-30
• /
• 1995

For the efficient interconnection between SMDS and LAN, an interconnection protocol architecture in the router is proposed in this paper. A control method of xongestion which is produced by this interconnection of SMDS and LAN is also proposed. Especially, the SIP level 3 of SMDS is devided into CS-SIP3 sublayer and CLNAP sublayer in order to circumvent the problems which are producted by the protocol difference of two networks and to consider the interconnection with B-ISDN in the future. In this way, the interconnection of SMDS and LAN is transparentlly achieved through CLNAP layer, and the interconnection protocol architecture becomes simple. To test the performance of the router, amodel of interconnection protocol which is proposed by this paper is simulated using sliding window flow control. The simulation results show that the throughput of router is increased. The packet delay and the rate of packet discard are also decreased.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.11 no.3
• /
• pp.58-66
• /
• 2008

In this paper, we have proposed a method and procedure which can find out the unknown network protocol. Although it seems to be difficult to identify the protocol, we can find out the rule in the packet according to the method we have proposed. We have to recognize functions of the system and make the list of events first. Then we capture the network packet whenever the event are occurred. The captured packets are examined by means of the method that is finding repeated parts, changed parts according to the input value, fixed parts and changed parts according to regular rules. Finally we make the test program to verify the protocol. We applied this method and procedure to upgrade Electronic Warfare Test System which is operated by ADD. We have briefly described the redesign of control and analysis software for Electronic Warfare Test System