• Journal of Information Technology Applications and Management
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• v.13 no.2
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• pp.87-97
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• 2006

Due to limited radio resource, an effective paging strategy is essential for improving the utility of radio channels. In current mobile communication networks, when a mobile-terminated call occurs, the network locates the mobile by paging all cells within the location area simultaneously. In this study, we introduces paging strategies that can page some cells or only one cell within the location area to reduce paging cost on radio channels using paging agents. We propose another new paging strategy that can page only one cell within the location area and may have better performance. We also compare the performance of our proposed paging strategy with the performance of the current simultaneous paging strategy and some new paging strategies using paging agents. This paper suggests the most effective paging strategy using mathematical models. The result of this research will be used to select a proper paging strategy in the mobile communication networks.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.115-118
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• 2003

In this paper, we analysed the technical characteristics of power line communications interfering marine mobile services. The various radio services including marine mobile potentially affected by unwanted radiation from telecommunication networks as PLT, VDSL, ADSL, etc. The radio spectrum is unique resource. In particular, the frequency range below 30MHz has extremely favourable propagation conditions allowing economic long range as well as low power communication radio services. The paper were as follows to identify marine mobile service that are likely to be affected by PLC and evaluate the protection needs and to investigate methods of measuring the emissions from PLC.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.12
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• pp.1240-1247
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• 2011

The localization of mobile robot in environment is a major concern in mobile robot navigation. So, many kinds of localization techniques have been researched for several years. Among them, the positioning system using ultrasound has received attention. Most of these ultrasonic positioning systems to synchronize the transmitters and receivers are used for RF (Radio Frequencies). However, due to the use of RF, the interference problems can not be avoided and the performance of radio frequencies directly affects the positioning performance. So we proposed the ultrasonic positioning system without synchronizing RF. The proposed system is based on existing USAT (Ultrasonic Satellite System) adopted infrastructure transmitting type, and consists of transmitter and receiver synchronizing modules instead of the radio frequency transmitters and receiver. The ultrasonic transmitters and receivers are synchronized individually by the transmitter and receiver synchronizing modules. In order to calculate the bias between the transmitter and receiver synchronizing modules, new positioning algorithm similar to GPS was proposed. The positioning performance of the improved USAT without synchronizing RF and the validity of the proposed positioning algorithm are verified and evaluated by experiments.

• 한국ITS학회:학술대회논문집
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• v.2006 no.10
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• pp.191-194
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• 2006

• ETRI Journal
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• v.26 no.5
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• pp.493-496
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• 2004

An effective paging strategy is essential for improving the utility of radio channels. This paper proposes a two-step paging strategy which involves using base station paging agents to page a single cell at each paging. An analytical model is used to evaluate the performance of the proposed strategy. The proposed strategy is compared with the traditional simultaneous paging strategy and a recent proposal using the base station paging agents. The numerical results showed that the proposed strategy proficiently reduces paging cost on radio channels compared with other paging strategies.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.273-278
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• 2007

In the next generation wireless mobile network, various methods are studied to offer interworking and mobility between various radio networks. To offer these harmoniously, network adaptation methods based on IP is generalized, and specifications of host-based mobility method with Mobile IPv4 and Mobile IPv6 to offer IP's mobility are defined in IETF specially. However, it is insufficient to satisfy quality of service that should be offered in wireless mobile network environment. Alternatively studies about Network-Based Mobility of Proxy Mobile IPv4, Proxy Mobile IPv6 etc. are preceded. This paper presents optimum plan that can offer mobility in the next generation radio transfer communication network by comparing and analyzing IP mobility methods divided by Host-based Mobility and Network-based Mobility.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.5
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• pp.431-441
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• 1997

In this paper, a performance evaluation method for the Trunked Land Mobile Radio System, so called TRS(Trunked Radio System), is presented. The proposed evaluation method employs LCD(Lost Call Delayed) system model and Erlang-C distribution. In this system, queues are used to hold call requests that are initally blocked. When a user attempts a call and a channel is not immediately available, the call request may be delayed until a channel becomes available. For evaluating system performance, therefore, the probability that any caller is delayed in the queue for a waiting time greater than t seconds is derived and simulated by using such parameters as total number of available channels, traffic load and average duration of a call. Furthermore, the performance of the message and the transmission trunked channel assignment strategies is compared. The performance simulation results show that transmission trunking is shown to be more efficient than message trunking.

• ETRI Journal
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• v.29 no.5
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• pp.569-595
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• 2007

Particularly in wireless communications, link errors severely affect the quality of the services due to the high error probability and the specific error characteristics (burst errors) in the radio access part of the network. In this work, we show that thorough analysis and appropriate modeling of radio-link error behavior are essential to evaluate and optimize higher layer protocols and services. They are also the basis for finding network-aware cross-layer processing algorithms which are capable of exploiting the specific properties of the link error statistics, such as predictability. This document presents the analysis of the radio link errors based on measurements in live Universal Mobile Telecommunication System (UMTS) radio access networks as well as new link error models originating from that analysis. It is shown that the knowledge of the specific link error characteristics leads to significant improvements in the quality of streamed video by applying the proposed novel network- and content-aware cross-layer scheduling algorithms. Although based on live UMTS network experience, many of the conclusions in this work are of general validity and are not limited to UMTS only.

• Journal of Multimedia Information System
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• v.7 no.3
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• pp.221-230
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• 2020

Used optimization techniques as solution for mobile network have been implemented as a reference systems for various applications against fading and signals perturbation, in addition each transition to 5th generation telecommunication standards require a deep studies in order to park an applied instantaneous process. The paper describes a preliminary planning and a careful preparation to update both subscriber radio access network as well as data transmission network this approach conducts to make network resource updates invisible for customers and with minimal costs for mobile operators basically in terms of delay. In addition, network operators transit to mobile networks, multimedia services efficient delivery are considered the challenging application and the most promising for mobile network operators today, this work conduct to optimize video consumption of mobile users which are exponentially increasing. The interference is a complex phenomenon in mobile radio telecommunication system, and a mobile phone can be a source of interference to another one. Actual advances in technology necessitate the need for the complicated software solution that can take several unexpected phenomena in consideration to rise to a level higher than ever. The capability needs today require the use of Drive test which is used to take the performance of network in the field by using a special software called TEMS investigation, it have been implemented as standalone systems for various applications. The paper focuses on considering as the best technical for optimization of mobile networks, analysis and processing of signal, a Drive Test is the method used to take the performance of network in the field by using a special software called TEMS investigation. Most used in the world, this software is reputed to detect and analyze many problems of mobile network between the mobile phone and the transmitter: BTS in case of GSM and Node B for UMTS. An example of that is interference in radio communication. It exists permanently and it degrades considerably the quality of received signal when it exceeds certain levels.

• ETRI Journal
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• v.19 no.3
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• pp.202-227
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• 1997

This paper describes the development of the CDMA mobile station to support non-speech, mobile office services such as data, fax, and short message service in addition to voice. We developed some important functions of layer 2 and layer 3. To provide non-speech services, we developed a terminal adapter and user interface software. The description of development process, software architecture and external interfaces required to provide such services is given. The description of a TTA-62 message analysis tool, a mobile station monitoring software, and an automatic test system developed for integration tests and performance measurements is also given.