• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.4
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• pp.787-792
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• 2004

This paper shows the design, fabrication and performance of oscillator appled to 5.5GHz RF module for local wireless communication system. Super low noise HJ FET of NE3210S01 is used to obtain a good phase noise Performance. The design Parameters for the optimum operating performance are simulated with ADS simulation. The measured out Power is 10 dBm at 5.5GHz, the second harmonic suppression -31 dBc, and the phase noise characteristics -98.83 dBc at 100kHz offset frequency, respectively. This implemented oscillator is available to local wireless Communication system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.96-100
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• 2004

This paper shows the design, fabrication and performance of oscillator appled to 5.5GHz RF module for local wireless communication system. Super low noise HJ FET of NE3210S01 is used to obtain a good phase noise Performance. The design Parameters for the optimum operating performance are simulated with ADS simulation. The measured out Power is 10 ㏈m at 5.5GHz, the second harmonic suppression -31 ㏈c, and the phase noise characteristics -98.83 ㏈c at 100KHz offset frequency, respectively. This implemented oscillator is available to local wireless Communication system.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.82-86
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• 2001

This papers deals with feasibility study of wireless motion control. Wireless telecommunication advances with development of IT technology and extends more and more areas. So we selected Bluetooth out of the technologies(Bluetooth, SWAP(SharedWireless Access Protocol), IrDA(Infra Red Data Association), WLAN(Wireless Local Area Network)) which was developed for local data communication and set up simple experimental system for wireless data transfer and server and client program for wireless data transfer was wrote. We successfully transferred some data wirelessly with this program.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.4
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• pp.199-204
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• 1999

The continuing development of the sensors for the measurement of the safety of structures has been making a turning point in measuring and evaluating the larger civil structural system as well. However, there are still remaining problems to be solved for the extremely large structure because the natural damages of those structures are not so simple to be monitored for the reason of their locational and structural conditions. One of the most significant problems is that a number of cables which connect the measuring system to the analyzer are liable to distort actual data. This paper presents a new monitoring system for large structures by means of a local wireless communication technique which would eliminate the possibility of the distortion of data by noise in cables. This new monitoring system employs the wireless system and the software for data communication, along with the strain sensor and accelerometers which have been already used in the past. It makes it possible for the data, which have been chosen by the central controling system from the various sensors placed in the large civil structures, to be wirelessly delivered and then analyzed and evaluated by decision making system of the structures.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1055-1059
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• 2004

A RFID(Radio Frequency Identification) system is a kind of radio frequency communication system and a branch of automatic data collection system. RFID system consists of RFID tags(or transponders) and RFID readers(controllers). This paper deals with the wireless communication that acquires tag IDs through RFID readers, and show the implementation of the target system which transmits tag IDs and related information to the server on the Internet through the wireless local area network. Today's RFID systems are usually implemented with the wired communication environment. In this paper, however, RFID system is effectively realized with the widely deployed wireless local area network and various RFID data can be collected by the readers which are communicating with the wireless access points of the local area network. Through the Internet, users also can have easy access to the server on the web and retrieve, analyze, and utilize tags' information.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.998-1013
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• 2013

Wireless wearable sensor networks have emerged as a promising technique for human motion tracking due to the flexibility and scalability. In such system several wireless sensor nodes being attached to human limb construct a wearable sensor network, where each sensor node including MEMS sensors (such as 3-axis accelerometer, 3-axis magnetometer and 3-axis gyroscope) monitors the limb orientation and transmits these information to the base station for reconstruction via low-power wireless communication technique. Due to the energy constraint, the high fidelity requirement for real time rendering of human motion and tiny operating system embedded in each sensor node adds more challenges for the system implementation. In this paper, we discuss such challenges and experiences in detail during the implementation of such system with wireless wearable sensor network which includes COTS wireless sensor nodes (Imote 2) and uses TinyOS 1.x in each sensor node. Since our system uses the COTS sensor nodes and popular tiny operating system, it might be helpful for further exploration in such field.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.12A
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• pp.1349-1355
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• 2004

In tile wireless communication networks although the modulation and demodulation structure with proposed BOWLIS algorithm is a little confusing but we certified that it is fit structure in fast operation processing and high speed wireless LAM system that is more strong on frequence and electro magnetic interference because it process the inputted data within 2.8Us that is faster 0.4Us than 3.2Us in standard form. Also we certified that in the sigtlt of consuming power it is better than pipe-lined structure because of reducing the processing step to 4.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.1
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• pp.50-57
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• 2000

By supporting wireless communication technology, there is gradually expansion of the commercial application for Wireless Local Loop(WLL) technology, which is to replace existing telephone line with wireless one. The WLL system application helps a operator to have merits of the installation and maintenance of line and also a subscriber to make a high speed value-added service. As mentioned above reasons for both sides, many manufactories and operators are concerned with development and application respectively. This paper presents hardware implementation of Radio Port Controller(RPC) and also describes the system configuration, functions, and Inter Processor Communication(IPC) structure of RPC. We performed inter-module communication test via IPC backplane bus. And inter-module integration test also completed through data communication and signal waveform measurement repeatedly.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.4
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• pp.764-771
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• 2005

As high-speed class broadband communication services have come in earnest broadband communication services are well regularized, utilizing not only wire but also wireless. One of wireless communication systems named B-WLL system, which provides high-speed broadband communication services, gives users inconvenience because it utilizes wire in the service area. In order to overcome this drawback, local wireless construction with ubiquitous environment has been considered in a new service demand area. We bring forth a scheme of cell Planning with 2 GHz frequency for wireless LAN construction which provides connection and mobility with no restrictions in time and locations.

• Journal of the Semiconductor & Display Technology
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• v.3 no.4
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• pp.13-17
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• 2004

As the usage of wireless LAN becomes common in working environment, the number of database systems that support both wired and wireless users increases rapidly. The characteristics of wireless LAN that its speed is slow relatively comparing to wired network and the users in its environment connects to different communication points as they moves creates another challenge to be resolved in database systems. In the environment of hybrid communication systems, wired and wireless for voluminous data amount and a number of users, the two layer architecture of the conventional client-server database systems has limitation in the system performance. This is due to that server is the only point of data service in client-server database systems. In this paper, we discuss a new extended database system architecture that data services are distributed among servers and clients based on user database access patterns in order to improve system performance. We analyze the expected system performance by using simulation technique and prove the practical utilization of the system by demonstrating experimental results.