• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.337-339
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• 2005

The demand for a real-time image surveillance system using network camera server is increasing as the network infra has been grown and digital video compression techniques have been developed. The image surveillance system using network camera server has several merits compared to existing real-time image surveillance system using CCTV. It would be more convenient if wireless realtime image transmission were possible. In this paper, a bluetooth module is designed and implemented for a real-time image surveillance system to send and receive informations wirelessly. It may simplify the system development procedures and increase the productivity by low power consumption, low cost, and simple wireless installation. A scatter-net formation is proposed using dynamic and distributed algorithm so that the network connection is reliable.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.713-718
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• 2006

이전의 스캐터넷 관련 연구들은 특정 지역내의 모든 장치들을 단시간 내에, 또는 최적의 성능을 내도록 형성하는 방법을 제안하였다. 그러나 실제 응용에서는 같은 사회적 그룹에 속한 사람들간의 통신이 더 빈번하게 일어나기 때문에, 같은 사회적 그룹에 속하는 장치를 먼저 소규모의 스캐터넷으로 연결하고 이렇게 형성된 스캐터넷을 터널로 연결하는 것이 더 효율적이다. 기존 스캐터넷을 평가하기 위해 제안된 APC는 병목현상을 고려하지 않기 때문에 스캐터넷의 성능을 나타내는 평가 기준으로 부적절하다. 따라서 우리는 성능에 압도적인 영향을 미치는 트래픽을 제외한 나머지 트래픽의 전송 성능 평균을 스캐터넷을 평가하는 기준으로 제안하였다. 그리고 터널의 개수와 위치가 전체 네트워크에 어떤 영향을 미치는지 알아보았다.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.492-496
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• 2006

WPAN(Wireless Personal Area Network)은 NEMO(Network Mobility) 환경에서 모바일 네트워크의 좋은 예가 될 수 있다. 특히, Piconet은 WPAN의 전형적인 형태이다. 이러한 Piconet의 모바일 디바이스는 배터리에 의해 전력을 공급받기 때문에 제한적인 에너지를 효율적으로 이용하는 것이 중요한 문제가 될 수 있다. 우리는 이 논문을 통해 Piconet이 모바일 네트워크를 형성할 때 에너지를 효율적으로 사용하기 위한 방법을 제시한다. 이를 위해 우리는 에너지 모델을 제시하고, Piconet 단위의 모바일 네트워크에서 Scatternet 형성을 통해 새로운 경로를 생성하여 전체 네트워크의 에너지 소비를 줄일 수 있음을 보인다.

• Annual Conference of KIPS
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• 2002.11b
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• pp.1411-1414
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• 2002

블루투스는 본래 이동전화 핸드셋, 헤드셋, 그리고 휴대형 컴퓨터와 같은 장치를 연결하는 케이블을 제거하기 위해 개발된 것으로 저가, 저 전력, 단거리의 무선 기술이다. 그러나 전자 제품간에 표준화된 무선 통신이 가능하게 됨으로 인하여 블루투스는 휴대전화나 PDA, 노트북 PC 와 같은 모바일 기기에 부착되어 무선 ad-hoc 네트워크를 구성할 수 있게 되었다. 블루투스는 시분할 다중화 시스템(TDM) 방식으로 최대 8 개의 블루투스 기기가 모여 하나의 채널을 공유하는 '피코넷(piconet)' 을 형성할 수 있고 여러 개의 피코넷을 연결하여 '스캐터넷(scatternet)' 이라는 더 큰 네트워크를 구성할 수 있다. 이러한 블루투스 네트워크에서 기존의 브로드캐스트 서비스는 단순한 재전송 방식으로 인해 신뢰성과 효율성에 있어서 많은 문제점을 안고 있으며 블루투스의 특징을 고려하지 못하고 있다. 따라서 본 논문에서는 블루투스 네트워크에서 브로드캐스트 패킷의 수신을 보장하면서 대역폭을 효율적으로 사용하는 브로드캐스트 패킷 전송 기법을 제시하고자 한다.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.476-479
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• 2003

Recently, Bluetooth has been regarded as a new technology for short-range wireless connection. Although initial application of Bluetooth technology has been focused mainly on replacing cables between hand-held devices due to a limited packet size and short-range, general wireless telecommunication such as PAN and Ad hoc networks via Bluetooth-equipped devices is expected to be one of the most popular applications. Wireless equipments have been used to exchange data between host and mobile unit. The exchanging data may be several bytes of control command and the value of sensors with ultra-sonic, vision sensor, and encoder from mobile robot. However, most wireless equipments have some drawbacks such as lack of authentication, large size and high price. On the other hand, the benefits of Bluetooth are small size, low power, low price except short-range. Especially, there are some difficulties when wireless modules are used in indoor environments. In this paper, a method of using wire network in Bluetooth network is investigated as a solution to overcome the short-range problem of Bluetooth and difficulty in indoor environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3B
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• pp.112-122
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• 2008

Basing on Piconet, The Bluetooth System forms network and transmits data. There is one Master and maximum 7 Slave bluetooth devices in one piconet. A job scheduler performed by Master bluetooth device, gives the chance of data transmission to Slave bluetooth devices, which connected to Master, using polling method in piconet. The maximum data rate is 723.2 kb/s when it uses ACL link with DH5 packet type in a piconet which is constructed by two bluetooth devices. However, if there are one master and two slave devices in a piconet, then the maximum data rate is reduced to a half(361.6kb/s), because a master device has to support same data rate for all connected devices. And, there is the defect in scatternet when data transmission rate becomes low(Maximum rate: 302.2kb/s). This paper proposals the new ad-hoc network topology called "DoublePico"for overcome the low data transmission in scatternet which is constructed by piconets. The method of doublepico that represented in this paper makes high data transfer rate(Maximum rate: 457.57kb/s) in bluetooth ad-hoc networks.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.11
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• pp.1052-1057
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• 2004

Bluetooth technology is essentially a method for wireless connectivity of a diverse set of devices ranging from PDAs, mobile phone, notebook computers, to another equipments, The bluetooth system both point-to point connection and point-to multipoint connection. In point-to multipoint connection, the channel is shared among several bluetooth devices. Two or more devices sharing the same channel form a piconet. There one master device and up to seven active slave devices in a piconet. The radio operates in the unlicensed 2.45GHz ISM band. This allows users who travel world-wide to use bluetooth equipments anywhere. Since the link is based on frequency-hop spread spectrum, multiple channels can exist at the same time. The bluetooth standard ha s been suggested that bluetooth equipments can be used in the short-range, maximum 100 meters. It has been defined that the time takes to setup and establish a bluetooth connection among devices is 10 seconds. It is a long time and may be a cause to lose a chance of finding other non-fixed devices. We propose a routing protocols for scatternets which can be used to control a mobile units(MUs) in this network. The proposed routing protocol is composed of two kinds of bluetooth information, access point(AP) and MU.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.5
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• pp.173-178
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• 2010

In this paper, we analyze the performance of multilink Bluetooth service and design the multilink application between various Bluetooth devices. There are many restrictions for the Bluetooth based multilink services. Especially, these restrictions occur due to SCO and ACL which construct logical links. In forming ake a scatternet, only one SCO link can be utilized. Also, the number of ACL link depends on the number of RFCOMM channels. High quality audio data streaming cannot be supported by using SCO link. In that case, ACL link should be used for the audio streaming and the data rate of other data links decreases. We implemented the multilink services to verify the considerations for the multilink service.

• Journal of Advanced Navigation Technology
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• v.11 no.3
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• pp.281-287
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• 2007

The Bluetooth technology represents an attractive approach to enable short distance wireless connectivity. The Bluetooth standard operates at the 2.4 GHz ISM band and offers the advantage of establishing ad hoc networks, called piconet and scatternet. The spread of Bluetooth implementation in consumer products opens up a new short range wireless networking applications. Bluetooth MAC avoids packet collision within a piconet by simple time multiplexing. But lack of synchronization among independent neighboring piconets introduces packet overlapping within a time slot. In this paper, the wireless network throughput of Bluetooth packet transmission system applying the pure-ALOHA and slotted-ALOHA MAC is investigated according to the impact of channel environment. From the obtained results, the throughput of the Bluetooth MAC protocol shown to offer good performance in wireless channel, and the results are useful for the implementation of Bluetooth networks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.7
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• pp.1262-1268
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• 2016

Bluetooth has been developed to be applied over the course of several versions in different environments. Especially low is moving to address the constraints, it gives a high utilization rate is faster than the Zigbee wireless LAN communication. To gather information on children's environmental copper transition to multiple versions. There is one limitation of Bluetooth requirements to effectively apply the information collected by Bluetooth. At the same time need to collect several information actions, Bluetooth can not connect to one of only seven Slave Master. In this paper, in order to take advantage of the many benefits of Bluetooth to gather the information by operating the Bluetooth operates in Beacon deliver packets of 168 bits, and the pairing between the master and slave unnecessarily generate a regular signal a large number of connections simultaneously Information We consider how to apply the effective policy that can be collected.