• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.6
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• pp.11-17
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• 2001

Design and implementation of the MAC protocol processor prototype for high speed wireless LAN, which has interface with 5GHz OFDM PHY layer, is presented. We analyze the IEEE 802.11 MAC protocol specification and then separate the MAC protocol functions to be implemented by hardware and firmware and define the interface in which frames can be exchanged. That is, it is considered that high speed queue processing and interfaces with RISC processor and OFDM PHY layer. Protocol control and transmission/reception functions of the MAC functions are implemented in hardware in order to guarantee high speed processing in MAC layer. The developed MAC hardware block operates at 10MHz main clock. Therefore, transmission rate in PHY layer is about 80Mbps because data transmission/reception between MAC layer and PHY layer is performed as unit of octet. The designed FPGA MAC function chip has been implemented in wireless LAN test board and it is verified that DCF function is operated correctly.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.10
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• pp.108-117
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• 2007

RConsumer Portal is defined as "a combination of hardware and software that enables two-way communication between energy service providers(ESP, like KEPCO) and equipment within the consumer's premises". The portal provides both a physical link(between wires, radio waves, and other media) and a logical link(translating among language-like codes and etiquette-like protocols) between in-building and wide-area access networks. Thus, the consumer portal is an important, open public shared infrastructure in the future vision of energy services. This paper presents an XML based standard specification of service-oriented, open protocol for consumer portal system architecture. In the framework level, the XML protocol provides a useful bridge between services and platforms. The proposed standard protocol has been implemented into our developing consumer portal pilot system. The results imply the potential of global standards for consumer portal system by its minimum overhead in network and processor. The reposed XML is designated psXML in this paper.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11A
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• pp.1253-1262
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• 2004

The Data Over Cable System Interface Specification (DOCSIS) protocol enables the delivery of Internet Protocol(IP) traffic over Cable TV networks with significantly higher data rates. In this paper, we assessed the performance of the DOCSIS protocol using the OPNET. The simulation can be used to predict the upstream system throughput, mean access delay and channel utilization on varying packet size and transmission stream and wid/without concatenation, and it has shown that maximum system throughput is 4.6 Mbps for channel capacity of 5.12 Mbps and packet size of 1500 bytes. The mean access delay varies depending on the offered load, and it is assumed that the offered load does not exceed the capacity of the channel. Excess offered load causes service starvation according to the assigned priority.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1527-1537
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• 2006

The server system of digital contents has to how the context information about client devices to provide the appropriate contents for each device effectively. CC/PP standard specification is an agreement for describing and transmission of the information related with a client device. In this case, the information on device hardware and software, networks and user's preference is included here. In the mean time, WAP forum defined W-HTTP protocol to transmit the CC/PP profile information of a client device to a server system. However, the client devices which use existing HTTP protocol to transmit their information cannot provide the CC/PP profile information to a server. In this paper, we propose an effective method to create and provide the CC/PP profile in the clients which use not only HTTP protocol but also W-HTTP protocol to transmit device information.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.205-208
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• 2011

In recent years, the user interest has increased for DDS (Data Distribution Service) which is a data centric middleware based on publish-subscribe communication as the demands for real-time data exchange in distributed systems have been growing rapidly. To reflect these needs, many vendors and research groups provide their DDS middleware. However, there has been a problem with interoperability between DDS middlewares because of a lack of common communication rules such as the message exchange and the discovery manner. For this reason, OMG defines RTPS (Real-Time Publish-Subscribe) specification which is the standard network protocol used to exchange data between different implementations of DDS. In this paper, we analyze and design the SDP (Simple Discovery Protocol) of RTPS which enable DDS middleware to provide interoperable discovery mechanism.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.6
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• pp.597-604
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• 2019

In this paper, we propose an improved method on an adaptive application of the CPP(Chinese Postman Problem) algorithm to the protocol test suite generation for conformance testing. Also, we present an example application of this CPP algorithm to B-ISDN Q.2931 call/connection control procedure for the purpose of showing how it can be adapted to generate a test suite for conformance testing of a communication protocol. The proposed method has an advantage of an optimization technique which finds a minimum cost of test suite from a standardized specification, so this optimization technique of the CPP algorithm can be practically applied to a real environment for testing a conformity of a protocol implementation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1B
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• pp.75-85
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• 2012

In this paper, we introduce the case study on the certificate system for Auto Meter Reading protocol, Device Language Message Specification which is a common language between metering devices and protocol with compatibility and conformance to the IEC 62056 standards. KEPCO has contributed to improve interoperability between different devices of multi vendors through the DLMS standard tests and led the smart metering industry in Korea. KEPCO has AMR system and successful business model for 550 thousands of households based on 24Mbps broadband powerline communications using its infrastructure. We have plan to continue on standardization activities stratagemically by participating in IEC working groups for the purpose of occupying the core technology of Smart Gird.

• Journal of KIISE:Information Networking
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• v.36 no.3
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• pp.184-190
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• 2009

WiBro has advantages when both WLAN and 3G UMTS are adopted. Much research is being carried out in this area. However, the WiBro specification does not consider end-to-end security. Hence, another security protocol has to be adopted to support secure communication. Most previous research only focused on WiBro MAC performance improvement or security. In this paper, we adopt a security protocol such as IPsec, TLS, and DTLS, well known end-to-end security protocols, to make full use of WiBro in the IP network. Using NS-2 we simulated the adoption of end-to-end security protocol and evaluated performance and usability. Simulation shows DTLS had some performance advantages. All the protocols, TLS and IPsec are also suitable for use in WiBro.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.1
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• pp.1-9
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• 1986

This is the third part of the four-part paper describing the development of a packet-switched computer communication network named the KORNET. In this paper we describe the design and implementation of the X.25 protocol connecting packet mode data terminal equipments(PDTE's) with data circuit terminating equipments(DCE's). In the KORNET, the X.25 protocol has been implemented on the line processing module-A(LPMA) of the network node processor(NNP). In the implementation of X.25, we have divided the software module according to the service function, and have determined the the rules that interact between the modules. Each layer protocol has been developed using the technique of the finite state machine. Before the actual coding of softwares, we hafve used formal software development tools based on the specification and description language (SDL) and program design languate (PDL) recommended by the CCITT. In addition, for the efficient operation of the X.25 protocol system we have analyzed the system performance and the service scheduling method of each module. The results will also be given.

• The Transactions of the Korea Information Processing Society
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• v.4 no.7
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• pp.1821-1841
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• 1997

This paper presents an automated protocol conformance test sequence generation based on formal methods for LOTOS specification by using and applying many existing related algorithms and technique, such as the testing framework, Rural Chinese Postman tour concepts. We use the state-transition graphs obtained from LOTOS specifications by means of the CAESAR tool. This tool compiles a specification written in LOTOS into an extended Petri net, from which a transition graph of a event finite-state machine(EvFSM) including data is generated. A new characterizing sequence(CS), called Unique Event sequence(UE sequence) is defined. An UE sequence for a state is a sequence of accepted gate events that is unique for this state. Some experiences about UE sequence, partial UE sequence and signature are also explained. These sequences are combined with the concept of the Rural Chinese Postman Tour to obtain an optimal test sequence which is a minimum cost tour of the reference transition graph of the EvFSM. This paper also presents a fault coverage estimation experience of an automated method for optimized test sequences generation and the translation of the test sequence obtained by using our tool to TTCN notation are also given. A prototype of the proposed framework has been built with special attention to real application in order to generated the executable test cases in an automatic way. This formal method on conformance testing can be applied to the protocols related to IN, PCS and ATM for the purpose of verifying the correctness of implementation with respect to the given specification.