• Journal of Communications and Networks
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• v.4 no.4
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• pp.321-335
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• 2002

Emergence of the fourth generation mobile communication system (4G system) is now in its dawn. This article proposes a perspective framework on the 4G system, and discusses various kinds of system aspects and technological requirements in terms of novel service features, spectrum management, radio access technologies, wired access integration, core network, and mobile terminal. The focus of the article is to define the scope and features of the 4G system in an overall system/network viewpoint. From the foreseeable development trends, it is highly expected that whatever emerges in the 4G system will be some kind of constantly evolving and grand recursive concatenation of all the existing system/network developments.

• Journal of the Korea Safety Management & Science
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• v.9 no.1
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• pp.85-93
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• 2007

Recently, RFID technology is being widely embraced in the supply chain, by manufacturers, retailers, and logistics firms. This study shows the RFID system to provide location based service for commercial vehicle by integrating tracking function of GPS with Mobile service. For this, we configured PC-based terminal for vehicle and developed application consisted of RFID and GPS manager program. In web service module which uses mobile service, commodity information acquired from each vehicle at real-time is added at database and it is analyzed in various aspects to support management decision through the Legacy system.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.247-250
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• 2003

Mobile wire technology is a publicly available general purpose for Radio Frequency(RF) communication for short-range and point-to-multi point voice and data transfer. In this paper, we proposed a new technology of the synchronized frame structure which is based on the CDMA technique, and it's implemented into the VLSI design by FPGA. The developmental technique consists of an assigned coded type mobile communication equipments and available local mobile or wireless communication scheme quasi BT(Blue Tooth)'s functions as multiplexer or do-multiplexer for each other applications. We implement this architecture with special proposed frame structure in the local area network. Also, we expect the above proposed structure extend into the DS3 network architecture and applicable to the TE(Terminal Equipment) in the local communication area and the other one etc.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.407-410
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• 2001

Recently, wireless technology is widely used with mobile phone like Handhold terminal, PDA. The technology in internet is moving into wireless internet. The mobile platform technology is especially important as well as internet world. In this paper, commercial mobile products are described and standardization trends are also shown for the new future platform development. M-commerce application service is possible to spread over the mobile platform.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.1289-1292
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• 2002

The number of connected computers in the Internet, which has reached a state in which its address space is becoming insufficient is exponentially increased. Also nowadays modern Laptops and Mobile terminal are being used more and more. As hewn, the number of available IPv4 address is limited and many organizations have limited budget to use the global address. So the way to overcome such problems is using private addresses in their networks. In addition, the use of private address makes the system more secure. Moreover, we have considered about supporting of the scalability of data forwarding processes of nodes in their network especially Mobile IP data communication. Thus, we propose the integration of MPLS and Mobile IP network. Also we propose the security services of a constrained LSP for the MPLS payloads.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.1
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• pp.1-6
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• 2006

Previous to do business computerization of industry field, it isn't efficient for write down all account book. Recently many companies competitive is raised from competence improvement for a task and cost-cutting for electronic data processing system. Moreover, sudden increase of internet-user need effective management information system and share information because of network connection. Accordingly, it needs to get out of text base information system from multimedia base system and it need to introduce E-catalog system of merchandise information. In addition, it is required technological development and merchandising with movement, real time omnipresent. carrying. In this paper, established portable B2B system with movement of precious metals and jewels field's portable terminal from mobile technology.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.11
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• pp.57-66
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• 2004

It is widely accepted that the coverage with high user densities in mobile multimedia environments can only be achieved with small cell such as micro- and pico-cell. The smaller cell size causes frequent handovers between cells and a decrease in the permissible handover processing delay. This may result in the handover failure, in addition to the loss of some packets during the handover. In these cases, re-transmission is needed in order to compensate errors, which triggers a rapid degradation of throughput. In this paper, we propose a new handover scheme in the next generation mobile communication systems, in which the handover setup process is done in advance before a handover request by predicting the handover cell based on mobile terminal's current position and moving direction. Simulation is focused on the handover failure rate and packet loss rate. The simulation results show that our proposed method provides a better performance than the conventional method.

• Journal of Distribution Science
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• v.16 no.4
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• pp.67-74
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• 2018

Purpose - Most of the amendments to the law on the improvement of the distribution structure of mobile communication terminal equipment, the fully self-sufficient system of terminals, and the separated disclosure system on the terminals are aimed at securing transparency of the distribution structure by eliminating or reducing handset subsidies. This study investigates what items are important for the purchase of mobile phones in various and rapidly changing mobile phone markets from the consumer's point of view and tries to make a strategic suggestion for future mobile distribution strategies. Research design, data, and methodology - The procedure of this study takes place in four steps. In step 1, only the SF type respondents selected for this study were extracted through MBTI analysis. In step 2, they were divided into three hierarchies for the AHP analysis and each element was arranged. In step 3, the AHP analysis was converted to a Fuzzy-AHP number using the trigonometric centroid method. This was to eliminate the ambiguity of the response by converting into a fuzzy number even if data consistency was maintained with CI value below 0.1. In step 4, the number of converted 2-layer and 3-layer was combined to derive the priority when the final handset is selected. Results - First, the highest importance among the four items in the second tier was the terminal function item, followed by brand, price, and design item. Second, in the third tier, the highest importance was level of after-sales service, followed by device price, processing speed, ease of use, usefulness, and rate system. Third, the arithmetic average of the determinant of the fuzzy function showed that processing speed, ease of use and usefulness in the function item, level of after-sales service in the brand item, and device price in the price item were the five most important factors among 16 choice factors. Conclusions - First, there will be a change in the consumption patterns of consumers who have compared distributors and dealers to purchase handsets with more subsidies. Second, it is highly likely that people will purchase new handsets only when they need to change their devices because they can not receive subsidies by switching phone brands any more.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.5A
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• pp.294-304
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• 2003

For an efficient software download in cellular CDMA systems, session admission control based on area (SACA) is presented. In the SACA scheme, the base station only allows mobile terminal to start session when the mobile locates near the base station of a cell. A mobile that is located near cell center can request software download session, but the mobile that is far away from the center can request session only after arriving near the cell center. Session duration time follows exponential and Pareto distribution. Performance is analyzed in terms of handoff rate, mean channel holding time, session blocking probability and handoff forced termination probability. As analysis results, handoff rate between cells in the proposed scheme is reduced to 30 ~ 250 % compared to conventional scheme, according to traffic characteristics such as terminal speed, session duration time and the size of the allowable zone area in a cell for the start of the session. And new session blocking probability slightly decreases to 5 ~ 20 %, but handoff session forced termination probability drastically decreases to 35 ~ 220 %.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9A
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• pp.1295-1305
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• 1999

In this paper, we present the implementation and performance analysis of H.324M mobile multimedia terminal which s under standardization. The H.324M is the mobile extension of H.324 which is the standard for low bit rate multimedia terminals operating over GSTN. For H.324M, the multiplexing protocol (H.223) of H.324 is enhanced to protect data from the transmission errors over mobile channels. The multiplexing protocol of H.324M is classified into Levels 0, 1, 2, and 3 depending on the level of error protection. Each Level is analyzed according to different types of the data loss elements. Simulation results show that the loss caused by the corrupted flag and header produces the most serious performance degradation. Levels 1 and 2 which protect the header and flag are effective in reducing the total loss. Furthermore, the optimal flag length and threshold value for Levels 1 and 2 are determined.