• Journal of Industrial Technology
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• v.20 no.B
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• pp.227-232
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• 2000

ISDN AO/DI provides efficient communication. It dynamically allocates channels for bandwidth, which is key component for packet data communication. In this paper, we analyze performance improvement of ISDN AO/DI system with buffering scheme and compare with AO/DI system without buffering scheme. From the simulation of AO/DI with buffering scheme, we see that the required bandwidth is less than of the AO/DI system without buffering scheme.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.699-700
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• 2008

In this paper, we implement Mobile AP system, which has Multihoming function providing vertical handover between WiBro and HSDPA networks. We monitor packet drop in networks during binding updates(BU) and acknowledgement(BA) and analyze handover latency. We propose methodology to reduce handover latency and describe the further development direction of Mobile AP system.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1B
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• pp.1-12
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• 2002

In the multimedia CDMA mobile communication service, it is required to support various applications, such as voice, video, file transfer, e-mail, and Internet access, with guaranteed QoS. In the mixed traffic environment ,which consists of voice, stream data, and packet data, we analyze the network where preemptive priority is granted to delay-intolerant voice service and a buffer is offered to delay-tolerant stream data service. And, for best-effort packet data service, the access control by transmission permission probability is applied to obtain prominent throughput. To analyze the multimedia CDMA mobile communication system, we build a 2-dimensional markov chain model about prioritized-voice and stream data services and accomplish numerical analysis in combination with packet data traffic based on residual capacity equation.

• Journal of the Korea Society of Computer and Information
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• v.28 no.11
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• pp.81-87
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• 2023

Intrusion detection systems that learn metadata of network packets have been proposed recently. However these approaches require time to analyze packets to generate metadata for model learning, and time to pre-process metadata before learning. In addition, models that have learned specific metadata cannot detect intrusion by using original packets flowing into the network as they are. To address the problem, this paper propose a natural language processing-based intrusion detection system that detects intrusions by learning the packet payload as a single sentence without an additional conversion process. To verify the performance of our approach, we utilized the UNSW-NB15 and Transformer models. First, the PCAP files of the dataset were labeled, and then two Transformer (BERT, DistilBERT) models were trained directly in the form of sentences to analyze the detection performance. The experimental results showed that the binary classification accuracy was 99.03% and 99.05%, respectively, which is similar or superior to the detection performance of the techniques proposed in previous studies. Multi-class classification showed better performance with 86.63% and 86.36%, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6B
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• pp.527-533
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• 2006

In this paper, we analyze the performance of MAC (Media Access Control) layer in DSRC (Dedicated Short Range Communication). It will be widely applied for ITS (Intelligent Transportation System) services; for example ETC (Electric Toll Control), BIS (Bus Information System) etc., needed to small packet size. But If ITS service is evolving to advance ITS, ADIS (Advanced Driver Information Systems) and AVHS (Advanced Vehicle Highway System) etc, be needed larger packet size. In the future, it may offer more various services such as traffic information, collection, and multimedia information. There are two kind of physical media, IR(Infrared) and RF(Radio frequency). And each system has their own protocol that is adaptive in special characteristics of physical medium for using efficiently limited radio resources. In this paper, we analyze the special characteristics of each system. And we study practical use of some related services expected to be used in the near future, by analyzing the transmission efficiency in each DSRC system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7B
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• pp.469-476
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• 2008

In this paper we analyze the packet interference probability and the aggregated throughput of a WPAN in which a number of Bluetooth piconets share the ISM band with WLANS. Using an Adaptive Frequency Hopping algorithm, when the AFH is employed, the number of hops available to the Bluetooth piconets varies depending on the number of independent WLANs within the piconet's radio range. Using a packet collision model in a piconet cluster, we give an analysis of the packet interference probability and the aggregated throughput as a function of the available hops for the AFH algorithm. We also present an analytical model of packet interference with multi-path fading channel in a cluster of piconets. Through analysis, we obtain the packet collision probability and aggregated throughput assuming capture effect. Numerical examples are given to demonstrate the effect of various Parameters such as capture ratio, Rice factor and cluster size on the system performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.2857-2863
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• 2014

IR-UWB has been developed as a standard of indoor ranging technology, because it has robust and good transmission characteristics in indoor environments and it can be operated with low power. In this paper, a IR-UWB packet analyzer is designed and implemented based on IEEE 802.15.4a, which is useful in developing IR-UWB real time location system with resolution of a few ten centimeters. A sniffer device of the packet analyzer monitors IR-UWB wireless networks, captures MAC packet frames, and transmits packet frames to the packet analyzing computer. The packet analyzing program in a computer analyzes received MAC packet frames and displays parsed packet information for developing engineers. Developed packet analyzer is used to analyze IEEE 802.15.4a MAC protocol, and also it can be used in other IEEE 802 series MAC protocol by modifying some functions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.3
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• pp.577-585
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• 2004

System Packet Interface Level 4 Phase(SPI-4.2) is an interface for packet and cell transfer between a physical layer(PHY) device and a link layer device, for aggregate bandwidths of OC-192 ATM and Packet Over Sonet/SDH(POS), as well as 10Gbps Ethernet applications. In this paper, we performs the research for SPI-4.2. Also we analyze the performance of SPI-4.2 interface module after modeling using C programming language. This paper shows that SPI-4.2 interface module with 512-word FIFO depth is able to be adapted for the offered loads to 97％ in random uniform traffic and 94％ in bursty traffic with bursty length 32. SPI-4.2 interface module can experience an performance degradation due to heavy overhead when it massively receives small size packets less than 14-byte. SPI-4.2 interface module is suited for line cards in gigabit/terabit routers, and optical cross-connect switches, and SONET/SDH-based transmission systems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.434-437
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• 2021

Canopen over EtherCAT(CoE) is a Canopen protocol that operates based on EtherCAT in industrial sites. In order to analyze a CoE network system and a performance through packet sniffing and reversing, it is necessary to know Data Objects structure and changes of its value. However, since Data Objects in Canopen is dependent on the devices, there is a limitation by using an existing packet analysis program like a Wireshark. Therefore, we designed and developed a system that infers Data Objects structure and system configuration.