• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.3
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• pp.1-11
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• 1997

Since the radio spectrum is limited, future wireless system will have micro cellular architecture in order to provide multimedia traffic services on personal communicatons network. The small coverage area of micro cellular systems results in frequent hadnoffs and location updates. We focuse on network load and terminal power due to frequent location updates and propose a location tracking scheme using embedded-pager PCS terminals. The proposed scheme is expected to minimize theconsumption of PCS terminal powr and improve the receiving rate of callee because of the power saving mechanism and the embedded-pager PCS terminal. This paper proposes signaling flows among the network elements for the proposed location tracking scheme. The signaling flows are accomodated to not only the existed network architectures but alsothe ATM backbone network arcitecture. To verify the signaling flows, we used petri-Net model. The resutls show that the signaling flows are suitable to our proposed location tracking scheme.

• The KIPS Transactions:PartD
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• v.10D no.6
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• pp.1041-1048
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• 2003

This paper implements a remote image based metering(IBM) system which capture meter image, recognizes number automatically, and send the data wirelessly through PCS data network. We use existing gas/water meter and get NTSC camera image by installing small monochrome CMOS camera on the meter closely. For remote data transfer, we use SMS (short message service) that is provided by commercial PCS network. We developed DVR(digital video recorder) for capturing meter image and character recognition algorithm. In addition, hardware and software for SMS and meter selector were developed.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.630-632
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• 1998

The basic user location strategies proposed in current PCS(Personal Communication Services) Network are two-level Database strategies. These Databases which exist in the Signalling network always maintain user's current location information, and it is used in call setup process to a mobile user. As the number of PCS users are increasing, this strategies yield some problem such as concentrating signalling traffic on the Database, increasing Call setup Delay, and so on. In this paper, we proposed RCP(Reverse Connection setup Protocol) model, which apply RVC(Reverse Virtual Call setup) algorithm to PCS reference model, and CRCP(Cache algorithm in RCP) model, which adopt Caching strategies in the RCP model. When Cache-miss occur, we found that CRCP model require less miss-penalty than PCS model. Also we show that proposed models are always likely to yield better performance in terms of reduced Location Tracking Delay time.

• Journal of electromagnetic engineering and science
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• v.12 no.1
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• pp.1-7
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• 2012

In this paper, we investigated the throughput of a cognitive radio network where two primary frequency channels (PCs) are sensed and opportunistically accessed by N secondary users. The sharing sensing member (SSM) protocol is introduced to sense both PCs simultaneously. According to the SSM protocol, N SUs (Secondary User) are divided into two groups, which allows for the simultaneous sensing of two PCs. With a frame structure, after determining whether the PCs are idle or active during a sensing slot, the SUs may use the remaining time to transmit their own data. The throughput of the network is formulated as a convex optimization problem. We then evaluated an iterative algorithm to allocate the optimal sensing time, fusion rule and the number of members in each group. The computer simulation and numerical results show that the proposed optimal allocation improves the throughput of the SU under a misdetection constraint to protect the PCs. If not, its initial date of receipt shall be nullified.

• Journal of the Korea Safety Management & Science
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• v.1 no.1
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• pp.145-157
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• 1999

In this paper, a research on the structure and the network configuration of the location register(LR), which database of new locations and service informations of subscribers according to the movement of subscribers in personal communication system(PCS). since the traditional PCS manages all the databases with the location informations as a centralized type. The service informations of the subscribers are centrally controlled by the HLR. So there have been the heavy signal traffic and the call setup delay. In order to relieve such problem, the proposed types of the configurations are the distributed type of PCS scheme and the hierarchical PCS scheme. In the distributed scheme, each PCS has its own LR and in the hierarchical PCS scheme, several LR are grouped to from a layer so that overall structure is a tree style.

• Information and Communications Magazine
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• v.12 no.8
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• pp.53-64
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• 1995

In this article, criteria and considerations for selecting a domestic Personal Communications Services (PCS) system in Korea are presented and upbanded IS-95 Common Air Interface (CAI) is asserted to be appropriate as a result of evaluation by the criteria. And Shinsegi Telecomm, Inc. (STI) is claimed to be a suitable operator to provide PCS by upbanded IS-95 considering the experiences as the cellular operator adopting IS-95 CDMA technology. The PCS R&D plan and strategies of STI are given and the joint R&D plan with domestic manufacturers to develop PCS systems are explained. The results from R&D so far are mentioned. The PCS network architecture and various services-basic voice service, value-added services and wireless data services-are discussed.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.2
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• pp.123-131
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• 2009

Process Control Systems (PCSs) or Supervisory Control and Data Acquisition (SCADA) systems have recently been added to the already wide collection of wireless sensor networks applications. The PCS/SCADA environment is somewhat more amenable to the use of heavy cryptographic mechanisms such as public key cryptography than other sensor application environments. The sensor nodes in the environment, however, are still open to devastating attacks such as node capture, which makes designing a secure key management challenging. Recently, Nilsson et al. proposed a key management scheme for PCS/SCADA, which was claimed to provide forward and backward secrecies. In this paper, we define four different types of adversaries or attackers in wireless sensor network environments in order to facilitate the evaluation of protocol strength. We then analyze Nilsson et al. 's protocol and show that it does not provide forward and backward secrecies against any type of adversary model.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.6
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• pp.363-644
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• 1997

This paper presents the design and fabrication of a shaped-beam array antenna which will be used for a PCS basestation using structure that is coupled to a microstrip line by an aperture on the interening ground plane. The shaped-beam pattern is obtained by an antenna synthesis method. An array antenna considering the mutual coupling between array elements patches) and a feeding network are designed by CAD tools. The feeding network is designed by using the Wilkinson power divider to obtain the optimized shaped-beam. The designed results are compared with the measured data.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.359-362
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• 2002

The increase in the number of PCS base station and repeater has increased the level of interference between PCS carriers. In this paper, interference of singular PCS repeater out-of-band noise power on mobile phone is analysed and compared with that of unified PCS repeater for multiple PCS carriers. It is shown that unified PCS repeater provide about 2∼3dB signal gain in comparison with conventional PCS repeater. As a result, the interference of out-of-band noise power on mobile phone is reduced. It is expected that PCS carriers are able to build an environmentally-friendly communications infrastructure and reduce the cost by using unified PCS revealer and apply it for the deployment of IMT-2000 network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.214-217
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• 2001

This paper presents an implementation methodology of common Rf- integrated PCS base station system which, is capable of providing PCS services for 3 PCS carriers concurrently and wireless system performance evaluation data is shown. We have built up a common PCS base station system using a commonization module, which is consisted of a multi-channel combiner, duplexer, LNA, power divider, feeder line, and a common set of antennas. It was shown that the performance of the system within the total 30MHz PCS frequency range is uniformly acceptable and measured signal quality and coverage are equivalent to that of the individual PCS base station. It is expected that PCS carriers are able to save a huge amount of installation and maintenance expenses by installing and sharing this base station system. This paper forms a groundwork for deploying efficient and economical IMT-2000 network.