• 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.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.51-56
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• 2014

TETRA(TErrestrial Trunked RAdio) provide specialized disaster radio communication services as a standard European for digital TRS(Trunked Radio System). Especially, DMO(Direct Mode Operation) feature is used effectively in the radio shadow areas which base station does not propagate radio signal because it can communicate directly with terminal to terminal without base station's relay function. However, to effectively used DMO feature, radio coverage prediction information should be provided to users. Therefore in this paper, we were calculated link budget of TETRA DMO terminals which were distributing and operating in the country and then predicted reaching distance about radio propagation to be applied with path loss model.

• Journal of IKEEE
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• v.13 no.3
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• pp.87-94
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• 2009

TETRA(TErrestrial Trunked RAdio) is the wireless communication system generally adopted to public network and backbone network, as the technology of Trunked Radio System specified by ETSI(European Telecommunications Standards Institute) and currently adopted to the Electric Power IT Backbone Network in Korea. IEC 61850 is the protocol proposed for SAS(Substation Automation System) of SCADA(Supervisory Control And Data Acquisition) system. In this paper, IEC 61850 Server and Client simulator are used based on Linux operating system. The multi-functional gateway, which transforms the communication based on TCP/IP between IEC 61850 Server Simulator and Client Simulator to the one based on TETRA Packet Data Service, is developed such that IEC 61850 SCADA system is constructed based on TETRA.

• Journal of IKEEE
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• v.13 no.3
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• pp.95-102
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• 2009

TETRA(TErrestrial Trunked RAdio) is wireless communication system generally adopted to public network and backbone network, as the technology of Trunked Radio System specified by ETSI(European Telecommunications Standards Institute) and currently adopted to the Electric Power IT Backbone Network in Korea. DLMS(Device Language Message Specification) is used in order to meter an electric measuring instrument value. In this paper, DLMS Server and Client simulator are used based on Window operating system. The multi-functional gateway, which transforms the communications based on RS-232C between DLMS Server Simulator and Client Simulator to the one based on TETRA PEI(Peripheral Equipment Interface), is developed such that DLMS SCADA(Supervisory Control And Data Acquisition) system is constructed based on TETRA.

• Journal of the Korean Society for Railway
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• v.12 no.1
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• pp.45-54
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• 2009

TETRA(Terrestrial Trunked Radio) is the standard of D-TRS(Digital Trunked Radio System) developed by the ETSI(European Telecommunications Standards Institute). Currently, TETRA has been selected as Electric Power IT Wireless Backbone Network. Traditional distribution automation system has used the wireless network of Mobile Service Provider using CDMA(Code-Division Multiple Access) and WCDMA(Wideband CDMA) modem. Therefore, the development of gateway platform is indispensable according to the change to TETRA network. In this paper, we propose an embedded Linux-based Gateway platform for transmitting Industrial Electric Power IT protocol using TETRA network.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.210-215
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• 2003

At present, communication network for subway is making use of the train radio system for main network and normally established a base station every three subway station. It is talk over the telephone between a locomotive and the traffic control for careful train service. Besides, mobile telephone equipment is using for service improve and convenience to passengers such as 011, 016, 017, 019 and what not. However, the train radio system has been occurring a various problems when a state of emergency because it is able to compose only one communication route each base station zone. We could have improving like this problems through induce the TRS(Trunked Radio System), though because have been able to compose multilateral communication route in case of linking with LCX(Leaked Coaxial) cable which is established. Therefore, we could be able to a fitting meet the emergency as train firing etc.. and efficient use of limited frequency resources.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.5
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• pp.356-364
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• 2019

The Ministry of Science and ICT recently announced its policy direction that involves charging the economic value of radio spectrum for promoting its efficient usage. According to the policy, there will be much efforts to estimate the economic values of various usages of radio spectrum. In this study, the economic value of radio spectrum is estimated for trunked radio system(TRS) by employing the least cost alternative methodology. The proposed methodology estimates the value of radio spectrum according to the cost of an alternative that can be employed for providing the same service. The value of radio spectrum for TRS was determined on the basis of the cost associated with the provision of TRS through the LTE network, wherein the value of radio spectrum for TRS comprises the LTE network cost, capital expenditure for the LTE service, subsidy for the LTE handset, and compensation cost for migration. Results obtained from this study can aid in calculating the economic values of radio spectra for other services and applications.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.420_421
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• 2009

The digital TRS(Trunked Radio System) is an excellent alternative for the transmission medium for the DAS(Distribution Automation System). KEPCO(Korea Electric Power Corporation) made the power IT network with digital TRS system. The main function of the radio network is transmitting and receiving information for the DAS. KEPCO's digital TRS is based on TETRA standard. The digital TRS supports data communication for the electric power control and monitoring systems in various ways.

• Journal of Information Technology and Architecture
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• v.10 no.1
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• pp.93-100
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• 2013

The purpose of this paper is to present Smart Virtual TRS(Trunked Radio System) service that gives the TRS function in mobile network with smart phone application and server. TRS is essential equipment of logistics vehicle so, most of trunk drivers uses TRS frequently. Developed service is based on smartphone without TRS equipment. Therefore, Smart virtual TRS included in TMS(Transportation Management System) has some effects for logistics company. i) Smart Virtual TRS gives better communication environment between office and drivers. ii) Smartphone App gives flexibility to TMS functions. iii) Smart Virtual TRS gives cost reduction effect.

• Journal of Advanced Navigation Technology
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• v.17 no.5
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• pp.497-505
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• 2013

In TETRA(TErrestrial Trunked RAdio) standard, TMO(Trunked Mode Operation) communicates with the UE through the base station and it has a higher priority than DMO(Direct Mode Operation) which communicates with UE directly for channel allocation. As a result, the UE needs an algorithm which restricts the frequency allocation by TMO so that DMO can have a successful communication within the network. However, the TETRA DMO standard does not consider this issue. In this paper, we propose an active DMO channel selection algorithm which allocates a channel based on some additional information such as channel usage state of TMO and channel utilization of DMO. The experimental results show that the proposed algorithm outperforms existing DMO channel allocation scheme in terms of the transmission efficiency.