• Proceedings of the Acoustical Society of Korea Conference
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• 1992.06a
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• pp.155-159
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• 1992

본 논문은 디지틀 음성통신 서비스의 품질기준 (통화품질, 접속품질)을 설정하기 위한 실험용 통화모델 시스템의 사용자 접속 규격을 구현한 것이다. 본 논문에서 구현한 사용자 접속 규격은 디지틀 음성통신망에서 사용하려는 접속 protocol을 그대로 적용하여 실제의 상황과 같도록 하기 위하여 종합정보통신망 (ISDN)의 표준규격인 사용자 - 망 접속 규격을 이용하여 구현하였다. CCITT 권고안 I series의 규격을 만족하는 Protocol Simulator 와의 연동실험을 통하여 구현한 모델 시스템에 대한 사용자 접속 규격의 처리 및 성능을 확인하였다.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.109-112
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• 1999

In this paper, we propose more effective method of label allocation on Multi-Protocol Label Switching (MPLS) which is IP over ATM integrated model. We research the problems, one is using downstream label allocation method case, the other is using both downstream and upstream label allocation method. Easily we can solve this problem through the downstream-on-demand label allocation method with RSVP(Resource ReSerVation Protocol). In experiment we can find 1.5~28% error which will be fixed by using downstream-on-demand label allocation method.

• Journal of Astronomy and Space Sciences
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• v.13 no.2
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• pp.134-148
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• 1996

In this paper, in order to verify KITSAT 1/2 packet communication protocols, we model the AX.25 protocol and PACSAT protocol by using an extended Petri net and then verify the correctness, boundedness, liveness and deadlock freeness of packet protocols by utilizing reachability trees.

• Journal of Communications and Networks
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• v.6 no.3
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• pp.226-234
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• 2004

This work presents a deterministic channel that rules according to inverse a power propagation law. The proposed channel model allows us to derive the lower bound and upper bound of packet's capture probability in Rayleigh fading and shadowing cellular mobile system. According to these capture probabilities, we analyze the system performance in the case of finite stations and finite communicated coverage of a base station. We also adopted a dynamic backoff window size to discuss the robustness of IEEE 802.11 draft standard. Some suggestions and conclusions from numerical results are given to establish the more strong CSMA/CA protocol.

• International Journal of Contents
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• v.1 no.2
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• pp.13-17
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• 2005

Base Station Controller which belongs to IMT-2000(International Mobile Telecommunication - 2000) network has several types of structure for efficient control protocol. This difference of structure occurs two different protocols for call handling. Recently the need of IMT-2000 is highly increasing, so it is important to analyze the performance of processors and IPC(Inter-Processor Communication) module with structure of BSC and protocol difference. This paper presents the performance comparison of different types of BSC in view of processor utilization, waiting time, queue length and QoS(Quality of Service) through the simulation model.

• The Transactions of the Korea Information Processing Society
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• v.5 no.9
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• pp.2248-2255
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• 1998

The property of connectivity between DBMS and application system developed in java is very important under the distributed object environments with heterogeneous systems. In these days, mostly used JDBC 3-tier model, which supports the connectivity, has two problems: the one is the restricted connectivity needed for the Java applet as application programs and the other is the additional efforts to design and implemtnt in linking any application program with the middleware from being deficit of standard protocol. In order to solve these problems, we have worked on Enlarging the properties of JDBC 3 tier model by applying CORBA distributed object environments. Thus, the enlarged 3-tier model has an ORB-JDBC sub protocol for the client sub-protocol and a middleware whose property is supported by CORBA.

• The Journal of the Korea Contents Association
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• v.8 no.6
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• pp.43-53
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• 2008

Hyper text transfer protocol (HTTP) over transmission control protocol (TCP) is currently used to transfer objects in the Internet. Stream control transmission protocol (SCTP), an alternative to TCP, which allows for independent delivery among streams, and can thus reduce the mean response delay of web object. We present an analytical model to find the mean response delay for HTTP over SCTP, therefore, estimate the effectiveness of SCTP over TCP. Typical TCP delay models assume the wired environment. On the contrary, the proposed model in this paper assumes the multiple packet losses and wireless environment where fast retransmission is not possible due to small window. The estimated mean response time can be used the benchmark to meet quality of service (QoS) at end-user. We validate the accuracy of our model using experiments. It is shown that the differences between the results from model and those from experimental are very small below 6 % on average. We also find that the mean response delay for HTTP over SCTP is less than that for HTTP over TCP.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.4
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• pp.118-129
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• 2008

This paper describes an IEEE 802.15.4-based hierarchical sensor network model for a VAWS(Vehicle Approach Warning System) which provides the drivers of vehicles approaching a sharp turn with the information about vehicles approaching the same turn from the opposite end. In the proposed network model, a tree-structured topology, that can prolong the lifetime of network is formed in a self-organizing manner by a topology control protocol. A simple but efficient routing protocol, that creates and maintains routing tables based on the network topology organized by the topology control protocol, transports data packets generated from the sensor nodes to the base station which then forwards it to a display processor. These protocols are designed as a network layer extension to the IEEE 802.15.4 MAC. In the simulation, which models a scenario with a sharp turn, it is shown that the proposed network model achieves a high-level performance in terms of both energy efficiency and throughput simultaneously.

• The KIPS Transactions:PartC
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• v.8C no.1
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• pp.68-74
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• 2001

This paper mentions a centralized approach based on SNMP protocol and distributed approach based on mobile agent in network management s system. And it presents a few Quantitative models for systematically evaluating those two different approaches. To do this, we propose model m that is applicable under a uniform network environment, and compare network execution times of each paradigms based on parameters from s simulation. The model is then refined to take into account non-uniform networks. We show that it can reduce overall network execution times b by determining the best interaction patterns to perfo$\pi$n network management operations from this model. We believe that the model proposed h here should help us to decide appropriate paradigms and interaction patterns for developing network management applications.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.2
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• pp.209-217
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• 2014

Of several approaches for future Internet, separating two properties of IP address into locator and identifier, is being considered as a highly likely solution. IETF's LISP (Locator ID Separation Protocol) is proposed for this architecture. In particular, the LISP model easily allows for device mobility through simple update of information at MS (Mapping Server) without a separate protocol. In recent years, some of the models supporting device mobility using such LISP attributes have emerged; however, most of them have the limitation for seamless mobility support due to the frequent MS information updates and the time required for the updates. In this paper, PMIPv6 (Proxy Mobile IPv6) model is applied for mobility support in LISP model. PMIPv6 is a method that can support mobility based on network without the help of device; thus, this we define anew the behavior of functional modules (LMA, MAG and MS) to fit this model to the LISP environment and present specifically procedures of device registration, data transfer, route optimization and handover. In addition, our approach improves the communication performance using three tunnels identified with locators between mobile node and corresponding node and using a route optimized tunnel between MN's MAG and CN's MAG. Finally, it allows for seamless mobility by designing a sophisticated handover procedure.