• Journal of Digital Contents Society
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• v.7 no.3
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• pp.139-145
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• 2006

Short-range wireless transmission and networking technologies are becoming increasingly important in enabling useful mobile applications. Bluetooth and IEEE 802.11b standards are the most commonly deployed technologies for WPAN and WLAN. This paper investigates the effect of short range wireless channel on the performance of MC-CDMA/BPSK system and Bluetooth GFSK signal transmission in AWGN and Rician fading environments. And we investigate performance degradation due to interference effects in short range wireless channel. We firstly derive a equation for the bit error probability in additive white Gaussian noise depending on MC-CDMA/BPSK signal and GFSK modulation signal parameters according to the Bluetooth RF standard. Then, from this error rate expression we calculate the mean error probability for MC-CDMA/BPSK signal and Bluetooth GFSK signal in Rician fading and interference channel. In particular, the impacts of the Rician fading depth and interference level on the error probability is shown in BER performance figures.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.167-170
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• 2015

In this paper, we propose the Micturition training and Automatic feeding system to enable busy modern people can grow pets more efficiently. This system will be able to operate a smart phone application with a Bluetooth, furthermore, by using the Wifi access the Internet from anywhere and to operate remotely. This system is divided micturition board feeding unit. micturition board consists of a water pressure sensor for detecting micturition and recorder module, speaker for voice output, feeding unit consists of two servo motor for auto feeding and Bluetooth sensor for remote control. Both micturition board and feeding unit produced Arduino board and C language-based Arduino sketch program, feeding unit was able to communicate with the library to support Bluetooth communication.

• Journal of the Korean Society of Radiology
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• v.2 no.1
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• pp.5-10
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• 2008

This study developed a PDA based wireless communication radiation measuring instrument using Bluetooth. The proposed system is composed of Student Radiation Monitor of Vernier using GM (Geiger Mueller) counter tube as a radiation measuring sensor, LabPro of Vernier as a module for data collection, Promi SD 101 of Initium, which can make Bluetooth communication up to 30 m, for wireless data transmission, and HP 5550 embedded with Pocket PC 2003 as OS for data storage and display. Because GM counter tube is used as a radiation measuring sensor, the system cannot measure radiation energy but measures count volume and count rate. When the result of natural radiation measuring by the PDA based system was compared with that by a PC based system, it was found that the proposed system transmits and receives data without distortion.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.309-315
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• 2017

Recently it has drawn much attention on the technologies about Internet of Things (IoT) which connects objects with constrained resource and heterogenous communication module in order to communicate information via internet. We propose a real-time sensor monitoring system based on IPv6 over Bluetooth Low Energy (BLE), which is included in Bluetooth 4.2 Specification. Since this system uses a publish-subsribe based IoT protocol, so called Message Queueing Telemetry Transport (MQTT), neither transforming network data nor any proxy server is needed in order to transmit data. Through the web client connected to this system, you can monitor sensor data sent by BLE device in real-time, intermediated via MQTT broker and then delivered to the client via HTTP and websocket protocol. In this paper we evaluated network capacity and availability of the implemented test platform. Thus by using this system it is possible to make development cost low and to construct IoT network with heterogenous devices easily.

• The KIPS Transactions:PartC
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• v.10C no.2
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• pp.185-190
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• 2003

Bluetooth communication is based on piconet, which is composed by one master and maximum seven slaves. Several piconets can be interconnected via an inter-piconet Bluetooth unit called a bridge unit to form a Bluetooth scatternet. This bridge node can make its presence in each piconet by switching. This switching must be carefully scheduled so that slot wastage and, hence, packet delays are minimized. In this paper, we introduce an efficient inter-piconet scheduling scheme based on sniff mode. This scheme tries to minimize the wastage of slots by having the bridge unit sniff with its peering masters with time limits and communicate with its slaves in remaining slots. The sniff time limits are determined adaptively based on the amount of traffic in each piconet. Simulation results show this scheme outperforms round-robin scheme based on sniff intervals of equal lengths.

• Journal of Internet Computing and Services
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• v.9 no.1
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• pp.159-170
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• 2008

The ubiquitous network revolution is beginning with the onset of digital convergence, whereby computers, horne appliances, and communications and broadcast media are being unified into digital media with the founding of the information super high speed. This technical advancement is creating a new culture and a new space and accelerating society's transition to the new and unique social paradigm of a 'ubiquitous society'. In particular, studies on ubiquitous communications are well underway. Lately, the focus has been on the Bluetooth technology due to its applicability in various environments. Applying Bluetooth connectivity to new environments such as ubiquitous or sensor networks requires finding new ways of using it. Thus, the scalable Bluetooth piconet scheme with independent slave device is proposed. It follows from work by Sea et al. But extended scatternet is not considered is Kiisc05 paper. Therefore, we propose secure bridge connection scheme for scalable Bluetooth scatternet.

• Journal of Information Processing Systems
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• v.5 no.4
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• pp.167-174
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• 2009

Nowadays, it has become common to equip a device with Bluetooth. As such devices become pervasive in the world; much work has been done on forming them into a network, however, almost all the Bluetooth Scatternet Formation Algorithms assume devices are homogeneous. Even the exceptional algorithms barely mentioned a little about the different characteristics of devices like computational abilities, traffic loads for special nodes like bridge nodes or super nodes, which are usually the bottleneck in the scatternet. In this paper, we treat the devices differently not only based on the hardware characteristics, but also considering other conditions like different classes, different groups and so on. We use a two-phase Scatternet Formation Algorithm here: in the first phase, construct scatternets for a specified kind of devices; in the second phase, connect these scatternets by using least other kinds of devices as bridge nodes. Finally, we give some applications to show the benefit of classification.

• ETRI Journal
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• v.25 no.5
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• pp.328-336
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• 2003

Bluetooth is a specification for short-range wireless communication using the 2.4 GHz ISM band. It emphasizes low complexity, low power, and low cost. This paper describes an area-efficient digital baseband module for wireless technology. For area-efficiency, we carefully consider hardware and software partitioning. We implement complex control tasks of the Bluetooth baseband layer protocols in software running on an embedded microcontroller. Hardware-efficient functions, such as low-level bitstream link control; host controller interfaces (HCIs), such as universal asynchronous receiver transmitter (UART) and universal serial bus (USB)interfaces; and audio Codec are performed by dedicated hardware blocks. Furthermore, we eliminate FIFOs for data buffering between hardware functional units. The design is done using fully synthesizable Verilog HDL to enhance the portability between process technologies so that our module can be easily integrated as an intellectual property core no system-on-a-chip (SoC) ASICs. A field programmable gate array (FPGA) prototype of this module was tested for functional verification and realtime operation of file and bitstream transfers between PCs. The module was fabricated in a $0.25-{\mu}m$ CMOS technology, the core size of which was only 2.79 $mm{\times}2.80mm$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1115-1122
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• 2003

In this paper we fabricated microchip antenna operating in bluetooth frequency bands(2.402∼2.480GHz). The antenna has a size of about 54mm${\times}419mm${\times}40.8mm, giving a total bluetooth PCB for support and chip of about 11mm${\times}44mm${\times}41.6mm. Bandwidth of the designed and fabricated chip antenna for bruetooth is 10.71 % at the resonated frequency of 2.45GHz and the resonant frequency and bandwidth versus change of any arbitrary feed point is observed. also, E-plane and H-plane in the Measured radiation pattern characteristic of chip antenna is compared and analyzed.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.9 no.1
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• pp.10-15
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• 2009

With the development of techniques, robots are getting smaller, and the number of robots needed for application is greater and greater. How to coordinate large number of autonomous robots through local interactions has becoming an important research issue in robot community. Swarm Robot Systems (SRS) is a system that independent autonomous robots in the restricted environments infer their status from pre-assigned conditions and operate their jobs through the cooperation with each other. In the SRS, a robot contains sensor part to percept the situation around them, communication part to exchange information, and actuator part to do a work. Especially, in order to cooperate with other robots, communicating with other robots is one of the essential elements. Because Bluetooth has many advantages such as low power consumption, small size module package, and various standard protocols, it is rated as one of the efficient communicating technologies which can apply to small-sized robot system. In this paper, we will develop Bluetooth communicating system for autonomous robots. And we will discuss how to construct and what kind of procedure to develop the communicating system for group behavior of the SRS under intelligent space.