• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.1 s.307
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• pp.7-12
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• 2006

In this paper we proposed a real-time remote monitoring system for interoperability between local area and wide area for wireless data communication. In local area, we used a miniaturized low-power wireless module and in wide area used CDMA Cellular System's Packet Data Service. The measurement results can be spread via Internet access in real-time

• Journal of information and communication convergence engineering
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• v.11 no.2
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• pp.82-94
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• 2013

In this paper, we propose a novel tunnel-free scheme in a proxy mobile IPv6 (PMIPv6)-based nested network mobility environment; several mobile nodes (MNs) and mobile routers (MRs) compose a hierarchical wireless network topology. Because tunnels created by several MRs overlap and data packets travel along several local mobility anchors (LMAs), the utilization of the wireless section is reduced and the packet forwarding path of the wire-line section is not optimal. In our tunnel-free scheme, the mobile access gateway (MAG) plays an important role in both the wireless and wire-line sections. Using a local binding update, this tunnel-free scheme forwards data packets with a host-based routing table without any tunnel. Establishing a direct tunnel between the MAG and the last LMA, this scheme removes nested tunnels between intermediate LMAs and MRs, and optimizes the forwarding path to the MN in the wire-line section.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.6
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• pp.15-21
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• 2009

The goal of wireless sensor networks is to collect sensing data on specific region over wireless communication. Sink node gathers all local sensing data, processes and transmits them to users who use sensor networks. Generally, senor nodes are low-cost, low power devices with limited sensing, computation and wireless communication capabilities. And sensor network applies to multi-hop communication on large-scale network. As neighboring sensor nodes have similar data, clustering is more effective technique for 'data-aggregation'. In cluster formation technique based on multi-hop, it is necessary that the number of cluster member nodes should be distributed equally because of the balance of cluster formation To achieve this, we propose a method to customize cluster member nodes for energy-efficiency in wireless sensor networks.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.43-48
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• 2012

In As the proliferation of wireless LAN and smart devices like smart phone, the importance of the wireless Internet local broadcasting service is increasing. In order to provide broadcasting data for the multiple devices, one-way roadcasting technology which could not support re-transmission, should be used and the receiving frame error is major problem. Furthermore unlicense devices cause interference to the receiver, burst frame error tends to be happened. In this paper, new method to overcome the burst and random frame error is proposed and the effect is analyzed.

• Journal of the Korea Society of Computer and Information
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• v.25 no.12
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• pp.109-117
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• 2020

In this paper, we analyze LADN(Local Area Data Network) that provides high throughput, low latency and service localization for 5G wireless networks and propose an enhanced control protocol design for LADN in 5G wireless networks. The concept of LADN is newly introduced in 3GPP 5G communication system and the LADN is a data network to which the UE(User Equipment) can connect with a specific LADN session only when the UE is located in a certain service area. If the LADN information between the UE and core network is not identical, the LADN session cannot be properly established. The proposed approach promplty synchronizes the LADN information between the UE and core network by using the specific registration procedure and appropriately establishes the LADN session, when the establishment of the LADN session is failed. Consequently, the proposed enhanced control protocol design(ECP) can prevent unnecessary signalling overhead and communication delay for LADN in 5G wireless networks.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.2
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• pp.67-73
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• 2008

Reconfigurable radio technology is needed to reconstruct frequency and modem functionality, which can be different within various regions. In addition, it makes it possible for a single mobile handset to support various standards of wireless communication, and thus plays a key role inmobile convergence. A MMIC VCO(Monolithic Microwave Integrated Circuit Voltage Controlled Oscillator) has been developed to produce high power and wide bandwidth that adapts the Clapp-Gouriet type oscillator for series feedback. We were fabricated based on the 0.15um pHEMT from TRW. The MMIC VCO was connected to an alumina substrate on the carrier for testing. This MMIC VCO module shows good performance when compared with existing VCOs. Futhermore, it has potential as a reconfigurable MMIC VCO for ubiquitous communications such as LMDS (Local Multipoint Distribution Service), VSAT, Point to Point Radio and SATCOM.

• Electronics and Telecommunications Trends
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• v.39 no.1
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• pp.25-35
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• 2024

Wireless communication, including mobile networks and local area networks, has become an essential service in the society. Wireless communication is evolving to include sensing services, as demonstrated by the increasing attention in organizations and standards such as 3GPP and IEEE 802.11. This survey presents technology trends in the integration of sensing and communication. The standardization status along with use cases provided by standards are explained. In addition, core and supporting technologies such as channel modeling, waveform design, and artificial intelligence are analyzed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.10
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• pp.1508-1517
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• 1993

In this paper, we propose the modeling of a wireless communication system using CSMA protocol, present analytical evalution and simulation as a function of arrival rate and mean END-to-END delay in the distributed packet radio network. Asynchronous 1-persistent CSMA protocol is used in wireless communication system with half duplex. We assume that all terminals are to be in the close range of each other, suitably located in the local area. The traffic presented to a common channel is assumed to be poisson distribution. Analytical model is based on a M/D/1 with breakdown. In conclusion for wireless network model proposed in this paper is suitable for packet arrival rate of 2 packet/sec with mean packet delay time less than 2 times the packet transmission time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1103-1108
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• 2003

In this paper, the characteristics of an inverted-F antenna for the 2.4GHz local wireless communication system have been analysed in terms of the variation of design parameters. The antenna can be integrated on printed circuit board, and the characteristics in terms of the variation of the gap between feed line and shorting stub, gap between antenna's leg and ground plane, antenna leg's width, substrate's height and dielectric constant are analysed. By using these characterization plot of design parameter, the tuning techniques are proposed to design optimum antenna. The designed antenna has 6.4 % frequency bandwidth for VSWR under 1.5 and 3dB gain.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.7
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• pp.1558-1564
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• 2004

This paper shows the design of Active antenna which appled to 5.5GHz RF module for local wireless communication system. The LNA, which was designed Super low noise HJ FET of NE3210S01, is used to obtain a good noise figure characteristics. And the microstrip patch antenna was designed to obtain omnidirectional antenna characteristics. The measured LNA gain is 15 dB, input & output return loss is under -20 dB and VSWR under 1.5. The Single microstrip patch antenna input return loss is under -29 45, VSWR under 1.2.