• ETRI Journal
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• v.10 no.1
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• pp.3-13
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• 1988

With the contunuing trends towards an information based society, telecommunications services are becoming an integral part of social activities. So, emphasis on ISDN is growing rapidly and placed on supporting integrated services delivery of different levels to the end user. The end user’s perception of an integraged services delivery(in particular, ISDN services) should reflect three interrelated capabilities, ISDN access capabilities and ISDN network capabilities. For turning the ISDN concept of above capabilities into reality, we have implemented the experimental system on user-network interfaces, which are three kinds of implementations in user access arrangements, namely basic access, intermediate rate multiplexed access and primary rate multiplexed access. Through these implementations, NTE(Network Terminating Equipment) is used for single basic access [2B+D], IMUX (Intermediate rate Multiplexer) for 4 basic accesses [4X(2B+D)] and PMUX(Primary rate Multiplexer) for [10/12 X (2B+D)]. This paper describes the outlines of system features on user access equipments, system architectures of testbed and experiment result of each access arrangements.

• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.248-251
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• 2000

The ATM-PON is regarded as an effective access network because the system transmits the various user's information through the passive optical splitter in a single platform. The ranging technology is to place all ONUs at the same distance virtually in order to form ATM-PON based on the Time Division Multiplexing (TDM). In This paper, We show the steps about ranging protocol based on ITU-T G.983.1 and ranging procedure modeling. Also, We implement the simulator that considers various environments to verify the time specifications of G.983.1. By using the simulator, We find out the wasted bandwidth which influences active ONUs during the ranging procedure.

• The KIPS Transactions:PartA
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• v.11A no.6
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• pp.433-438
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• 2004

In this paper, we describes the development of Bluetooth network Access Point(AP) for the access network connection of Bluetooth devices at home. Unlike headset, mouse, and keyboard, the AP should have capability to support multiple connection and stabilized network throughput. Our AP allows various kinds of Bluetooth terminals to access the access network like xDSL and PSTN(Public Swithced Telephone Network) stably. Especially, users can access the PSTN at home instead of expensive CDMA network through the AP by using the one-phone which is the cellular phone with the Bluetooth module.

• Journal of Korea Technology Innovation Society
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• v.4 no.2
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• pp.157-171
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• 2001

This paper discusses the economics of local loop architecture focusing on existing technologies, ADSL, HFC, and new one, PLC, and suggests a new modeling approach of access network system and the numerical equations. To modelize access network system and drive the numerical equations, we consider the double star and the tree & branch architecture and made block diagram of each access system. In addition, we introduce the density of subscriber as a variable and the equation of seeking the optimal number of cell in a service area. The economics of local loop architecture is analyzed in two ways, i.e. with and without consideration of the cost of cable and infrastructure. From the numerical analysis, we find that in case of not including the cost of cable and infrastructure, there is no much difference in the cost per one subscriber, while, in case of including it, there is remarkable difference among technologies. Therefore we conclude that the economics of local loop architecture is depend on the density of subscriber and existing network infrastructures.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.39-42
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• 2006

There are various analysis functions(including prediction of path loss, analyzing of capacity and coverage, etc.) of simulation tool to design and optimize the mobile communication network. Its reliability absolutely effects the performance of mobile communication network. Especially as the wireless network highly advancing focused on data service, it more needs to research and develop on the standard establishment of reliability of the simulation tool. Also it is important the systematic research how to improve the reliability of simulation tool. In this paper, to give the concrete process and skill about how to improve reliability, we define the kinds of reliability at first. And then we explain the comparison results between real field measurement data and theoretic simulation data.

• ETRI Journal
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• v.28 no.4
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• pp.513-516
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• 2006

Experimental demonstration of bipolar spectral encoding code-division multiple-access with modified pseudorandom noise codes is presented. Bipolar spectral encoding is achieved with an erbium-doped fiber amplifier amplified spontaneous emission source and arrayed waveguide gratings. The bit-error rate performance of 1.25 Gbps signal transmission over 80 km single mode fiber is measured in a multiple-user environment.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.5
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• pp.491-498
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• 2016

An ACL(: Access List), a list that determines network access, is used for the security of the network. An ACL if applied to a interface of router can filter particular packets. Also it can block or allow the access of certain unauthorized IPs or ports, based on the source address, destination address, and TCP/UDP port. This paper presents a simulation case to verify the effect of a router-based network applying Standard ACL or Extended ACL. The network was created through designing topology and then making a common virtual network using a Packet Tracer.

• Journal of Advanced Navigation Technology
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• v.10 no.4
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• pp.306-311
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• 2006

When the WiBro/WLAN hierarchical network is structured, a dual mode access terminal should keep WLAN module with power on state for operating in WiBro network outside of WLAN hotspot zone. Power consumption of user's access terminal can be increased to maintain WLAN module power on state of dual mode access terminal in WiBro network outside of the hotspot zone. This paper focuses on power saving strategy for a dual mode access terminal in WiBro/WLAN Hierarchical network to overcome problems regarding power. We will apply information about hotspot in WiBro network to establish the efficient power saving strategy for dual mode access terminal.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.778-781
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• 2005

In this paper, we describe a development of a Bluetooth Access Point for the WAN connection of home network devices. Especially, users can access the PSTN at home instead of expensive digital cellular network through the AP, using the 'one-phone', which is the Bluetooth enabled cellular phone. The simultaneous benchmark test about telephone service and LAN access service shows the perfect compatibility and reasonable performance of the access point. The one-phone service can become a convergence of wired and wireless communication through the AP.

• Journal of information and communication convergence engineering
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• v.10 no.2
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• pp.156-161
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• 2012

An increasing number of people who use a smart phone or tablet PC are accessing wireless networks in public facilities including cafes and shopping centers. For example, iPhones and Android Phones have been available since 2010. However, security incidents may occur through all sorts of malicious code infection of users' personal information during the use of an insecure wireless network. In this paper, we will describe the Wi-Fi protected access (WPA) and WPA2 encryption systems used to access a wireless network from a smart phone and tablet PC, and demonstrate the access point (AP) hacking process in a wireless network to which a password is applied on the basis of the analyzed WPA and WPA2 passwords. We will analyze the method of successful AP hacking and propose an approach to enhancing wireless LAN security. This study will contribute to enhancing the security and stability of wireless networks.