• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1B
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• pp.1-8
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• 2006

Currently, there are many efforts underway to provide Internet service on integrated wireless and wired networks. Supporting IP mobility is one of the major issues to construct IP based wireless network. Mobile IP has been proposed to solve the IP Mobility problem. But, in processing frequent handoffs in cellular based wireless access network, Micro mobility protocols have been proposed to solve these problems. Micro mobility protocols proposed the Cellular IP, HAWII, and Hierarchical Mobile IP. Cellular IP attracts special attention for it's seamless mobility support in limited geographical areas. New BS must be known to occur begging of handoff in Cellular IP indirect handoff. Therefore during perceiving of hanoff, packet loss or packet duplication still can occur in Cellular IP indirect handoff, which results in the degradation of UDP and TCP performance. In this paper, we propose a enhanced indirect handoff scheme for Cellular IP. Proposed handoff scheme is using a crossover node to minimize the signalling procedure and using a buffering to minimize the packet loss or packet duplication.

• Journal of Korea Society of Digital Industry and Information Management
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• v.4 no.4
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• pp.63-69
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• 2008

Recently, every student would take lessons without knowing no lecture in campus life. And, If you are a university student, you tired a course to register in a crowded. For solving this problem, we choose the cellular phone. Nowadays peoples have one cellular phone to one person in korea. Using cellular phone, you can use cellular phone anywhere any time. In this paper, we studied mobile synthesis system using mobile cellular phone. According to use mobile campus system, the university and students can use easy an one to one service in ubiquitous.

• Journal of information and communication convergence engineering
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• v.8 no.1
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• pp.1-5
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• 2010

In this paper, we propose for improving QoS in wireless micro cellular network using Cellular-IP/PRC(Paging Route Cache) with Paging Cache and Route Cache in Cellular-IP and propose for performance of realtime and non-real time handoff service using Handoff state machine Paging Route Cache. Although the Cellular-IP/PRC technology is devised for mobile internet communication, it bas its vulnerability in frequent handoff environment. On the other hand, Cellular IP combines the capability of cellular networks to provide high performance handoff and efficient location management of active and idle mobile users with the inherent flexibility, robustness and scalability found in IP networks. Also Cellular-IP/PRC use semi-soft handoff. During semi-soft hand off a mobile host may be in contact with either of the old and new base stations and receive packets from them. Packets intended to the mobile node are sent to both base stations and buffered, so when the mobile host eventually moves to the new location it can continue to receive packets without interruption. It should be suitable for realtime service such as multimedia traffic. But, much waste of resource will occur in this method, especially for non-real time services such as FTP and E-mail. Therefore, a new algorithm that performs different handoff according to characteristic of each traffic by use of reserved field in IP packet is proposed in this thesis. This hand off state machine using differentiated handoff improves quality of services in Cellular-IP/PRC. Suggested algorithm shows better performance than existing technology in wireless mobile internet communication environment. Matlab simulation results are improving QoS, show call drop and call blocking provided to Paging Router Cache during handoff state machine in Cellular-IP/PRC.

• Journal of Information Technology Applications and Management
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• v.13 no.1
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• pp.39-66
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• 2006

In a few years, a variety of mobile devices are expected to be utilized as a necessity for business as well as personal communications. Thus it is needed to conduct a comprehensive study on the acceptance of mobile devices in the mature market like Korea. This paper develops an extended technology acceptance model by including functional attributes of cellular phone and examines the determinant factors causing accepting cellular phones. Our empirical analysis through the internet survey shows that 1) among the determinant factors, perceived usefulness, perceived enjoyment or fun, and social pressure have positive direct impacts on the intention of accepting cellular phone, and 2) functional attributes of cellular phone affect the determinant factors differently.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.6A
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• pp.351-360
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• 2003

To provide good-quality services of multimedia in wireless mobile networks, QoS for multimedia traffic should be guaranteed. However, since the existing QoS guaranteed schemes are designed for fixed networks, they are inadequate in the wireless network environments. Recently, as the size of cells like micro cell or pico cell becomes smaller. Mobile hosts on micro cellular networks, change their location frequently. It causes many drawbacks such as delayed delivery, packet losses and signaling overheads. Because the existing schemes supporting interoperability between RSVP and Mobile If are designed for macro cell environments. Their uses in micro cellular networks can be restricted. In this paper, we propose the CRSVP(Cellular RSVP Protocol) which supports QoS in micro cellular network environments.

• Journal of the Semiconductor & Display Technology
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• v.10 no.3
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• pp.7-13
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• 2011

In Korea, the car mobile phone service had started in 1961 and with this Korea Mobile Telecommunications Services was established in 1984. Its service was mainly focused on the mobile phone service for the car which led the popularity of the full-scale mobile phone service. There are many kinds of materials, colors and patterns which are the elements of surface coating techniques. In light of that, we are focused on the UV coating that is ranked as an important part of the techniques in this study. In the first, the use of various materials for the cellular phone and surface processing techniques for the cellular phone were searched. On the basis of the results, the experiments of actual consumer experience with the exfoliation of the surface were done and through that we proposed the best way of processing the surface for the cellular phone and the materials. The result of the Wear Test showed that thick coating was detached more slowly and each company differed in their results with UV paints despite the same thickness of UV coating. The seal (UV) exfoliation of cellular phone is deeply related with the film thickness and the film formation when the users use the cellular phones and the exfoliation of the cellular phone surface will be decreased if the manufacturers meet the best conditions for the cellular phone.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.3
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• pp.79-89
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• 2010

Cellular and Smart phone through the business and real life is associated with an increasing number of information processing, Breaches associated with mobile terminal Tile has occurred and cause Crime and damage. In this paper, Cellular and Smart phone for mobile forensics SYN scheme and JTAG scheme to target Cellular and Smart phone for the extraction of forensic data will be studied. SYN, JTAG approach to forensic analysis indicate with the process, Every Smart phone's OS specific performance and data extraction were compared. In the laboratory, Cell and smart phone with the SYN scheme and JTAG scheme to extract forensic data Improvement compared to the extraction is presented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.912-919
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• 2005

The Growth in wireless Internet has made Networking possible at anytime and anywhere. So mobile devices like cellular phone and PDA are now used in various fields. In particular, the mobility of mobile devices has a great advantage in remote control. This paper designed and implemented a Mobile VNC system that transmitted the screen image of a remote computer, control the remote computer GU and monitor all by cellular phone. The proposed system consists of a Mobile Viewer un on the cellular phone, VNC Server m on a number of remote computers and a VNC Monitor. For communication between the VNC Server and the Mobile Viewer the MRFB protocol is used. The screen image transmitted to the Mobile Viewer is encoded in the PNG format supported by SK-VM, the Java execution environment of the Cellular phone. According to implementation results, the image is about $2KB\~8KB$. According to the 65 times transmission test, the average frame per second is 4.93fps in the emulator and a real cellular phone takes 0.8fps. Therefore, the proposed system is more efficient than existing systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9B
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• pp.774-782
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• 2003

Generally, in the Mobile IP technologies, the use of RSVP(Resource ReSerVation Protocol) is recommended in order to provide a mobile node real-time service. However, the handoff of a mobile node increases the registration delay, RSVP reservation delay and signalling overhead in the Mobile IP and RSVP interworking. Specially, the resource reservation on the path between a mobile node and a correspondent node is the duplicated reservation and then causes unnecessary creation of the signalling overhead and waste of the resource, since the majority of the path before handoff and after handoff is same. If the radius of a cell providing a wireless interface to a mobile node is small, the number of handoff will increase and also signalling overhead and duplicated resource reservation will increase. In this paper, we proposed the integration model of Cellular IP and RSVP with RSVP proxy scheme. Here, Cellular IP protocol minimizes registration delay, transfer delay, and loss by handoff in micro cell network, the RS VP proxy that minimizes the duplication of resource reservation prevents the path for RSVP session from change using the address for reservation of a mobile node. Proposed scheme was evaluated in comparison with the existing Mobile IP and RSVP interworking scheme using the probability of resource reservation fail to the radius of a cell and the handoff rate.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.65-69
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• 2006

Cellular network evolution and development of multi-function cellular phones introduce new mobile business mode. Cellular operators provide mobile internet services using the mobile browser such as ME and WAP and the mobile multimedia platform such as WIPI, J2ME, and BREW. New mobile applications are developed using mobile platforms provided by cellular operators as cellular phones having multimedia solutions such as camera, MP3, MPEG, 3D game engine, DMB, PAN such as bluetooth, IrDA, W-LAN, and location information using GPS are developed. Content providers have problems of redevelopment of a mobile application for different mobile platforms. In this paper, we propose a conversion solution for interoperability of applications developed on different mobile platforms of WIPI and BREW. We analyze APIs of WIPI and BREW and develop conversion solutions.