• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.358-360
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• 2002

Bluetooth는 기기들간에 고정된 제어 장치를 갖지 않고 각각의 이동 기기가 스스로piconet 이라는 불리는 네트워크를 구성하게 되고, 이 piconet을 확장하여 scatternet을 구성하게된다. 이 scatternet의 형태는 Bluetooth 망 전체 성능에 큰 영향을 미치게 되는데. 본 논문에서는 지금까지 제시된 scatternet의 구성 방법들을 알아보고 scatternet을 구성하기 위해 piconet간에 공유되는 bridge 노드의 숫자를 2개까지 늘려서 원활한 통신과 안정적인 망 구성을 위한 방안을 제시한다. 또한, 성능 분석을 위하여 Bluetooth 전문 시뮬레이터인 IBM의 BlueHoc을 사용하여 bridge 노드수와 scatternet을 구성하는 piconet수의 변화에 따른scatternet의 성능을 모의 실험을 통해 측정하여 보았다.

• Journal of KIISE:Information Networking
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• v.31 no.3
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• pp.314-326
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• 2004

Bluetooth has been reputed as a wireless ad-hoc networking technology supplying scalable and extensible networks between digital devices. For that kind of networks, scatternet is a most essential part in bluetooth. But past researches on bluetooth scatternet has proposed only possibilities of scatternet algorithm based on simulation results. And many of the researches failed in guaranteeing extensibility and flexibility and had many difficulties in real hardware implementation. In this paper, we proposed node ring scatternet(NRS) algorithm guaranteeing extensible and flexible networks. NRS algorithm is designed for hardware implementation using real commercial bluetooth module. That algorithm is divided into initial formation and reformation. For initial formation, we proposed limited SEEK/SCAN algorithm. For reformation, we proposed DIAC algorithm and Reserved Recovery Node algorithm. And we proposed SFMP(Scatternet Formation ＆ Management Protocol) in protocol stack for real implementation. NRS algorithm is operated in SFMP. Finally, we performed real hardware experiments and evaluated the proposed algorithm. In that experiments, we succeeded in forming scatternet up to 20 nodes. In comparison with other similar algorithm, proposed algorithm have the improvement in scatternet formation delay and success rate.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4A
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• pp.411-417
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• 2008

This paper proposes BSFP (Bluetooth Scatternet Formation Protocol), which establishes a multi-hop bluetooth scatternet. BSFP independently operates on each bluetooth device, does not require any information on neighbor devices at the very beginning, and can establish a scatternet even though all the devices are spreaded beyond the bluetooth transmission range. BSFP is composed of the following three stages; 1) Init stage to investigate neighbor nodes, 2) Ready stage to establish a scatternet using gathered local information at each node, and 3) Complete stage to use the determined scatternet links. In BSFP, the scatternet formation time does not significantly affected by the number of bluetooth devices and a robust mobile ad hoc network is formed because BSFP formulates a scatternet with many adjacent links to neighbor devices.

• Journal of Communications and Networks
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• v.8 no.1
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• pp.59-69
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• 2006

Bluetooth is reputed as a wireless networking technology supplying ad-hoc networks between digital devices. In particular, Bluetooth scatternet is an essential part of dynamic ad-hoc networks. Yet, there have not been sufficient researches performed on scatternet environment. This paper proposes a scatternet reformation algorithm for ad-hoc networks for instances where some nodes enter or leave the scatternet. The proposed algorithm is a general algorithm that can be applied to many types of Bluetooth scatternet regardless of the topology. The proposed algorithm is made for two reformation cases, i.e., nodes leaving and nodes entering. For the reformation when nodes leave a scatternet, the recovery node vector (RNV) algorithm is proposed. It has short reformation setup delay because the process involves a single page process (not including inquiry process). For the reformation when nodes enter a scatternet, the entry node algorithm is proposed. This is a simple and easily implementable algorithm. In this paper, real hardware experiments are carried out to evaluate the algorithm's performance where the reformation setup delay, the reformation setup probability and the data transfer rate are measured. The proposed algorithm has shown improvement in the reformation setup delay and probability.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.592-594
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• 2004

Bluetooth 칩셋의 생산량을 보면, 보이지 않는 곳에서 Bluetooth의 성장은 계속 되고 있다. [1] 그리고 Bluetooth는 Scatternet을 구성하여 Personal Area Network의 영역을 넘어 Senssor network에 적용하는 것이 가능하다. 그러나 Bluetooth specification[2]에서는 Scatternet Formation 방법에 대해 제안하지 않는다. 이를 개선하기 위해 BTCP (Bleutooth Topology Construction Protocol)[3], Bluetree[4], Bluenet[5], TPSF(Two-Phase Scatternet Formation) protocol[6]이 제안되었다. 본 논문에서는 이러한 protocol들을 개략적으로 설명하고 그에 대한 장단점을 알아보겠다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10A
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• pp.838-846
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• 2003

In Bluetooth networks, the scatternet is defined as the internetworking of multiple piconets. Currently, Bluetooth standardization does not include the formation issue of scatternet by piconets. The existing formation algorithms of scatternet do not support the features of ad-hoc networks, which cause the performance degradation of systems when the nodes have certain degree of mobility. Therefore, as the formation of scatternet gets complicated, the throughput is lowered and the delay increases due to the inefficient architectural problems. In this paper, we propose the distributed formation scheme for bluetooth in scatternet, in which the nodes are spread out to form scatternet. Simulation results show that the proposed algorithm outperforms the conventional schemes.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.251-259
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• 2007

A Bluetooth ad hoc network can be formed by interconnecting piconets into scatternet. Many algorithms of scatternet formation have been proposed so far. However, these have a problem that takes a long time to reform scatternet, especially for the case of master moving out. In this paper we propose a Fast-Recovery algorithm. which aims at reducing the time of scatternet reformation owing to master moving out. In the algorithm, we select a slave with the weigh similar to its master as Sub-Master from a piconet device table created by the master When a master leaves its piconet is detected by its slaves, the Sub-Master becomes the new master of the piconet instead of the old and directly connect to other slaves and bridge(s) through piconet device table in page state.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.9 s.339
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• pp.57-64
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• 2005

A Piconet consists of Master device and several Slave devices. Master and Slave devices are transmitted using TDD (Time Duplex Oivision) in a Piconet. A Scattemet constructed by several Piconets communicates by a Piconet. Bluetooth Specification defines the meaning of a Scatternet. But the formation and scheduling method is not defined. For the efficient formation of a Scatternet, the preceding research proposes a tree-shape topology Scatternet. But this research passes over the characteristic of Bluetooth transmission carried out by a Piconet in the Scattemet. So this Paper proposes a efficient throughput tree formation Scatternet algorithm To improve the throughput of a Scatternet, this paper proposes a tree tolopology that guarantees the efficient throughput of a Piconet

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.63-67
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• 2001

본 논문에서는 블루투스 Scattenet 환경에서 임펄스 잡음의 영향을 분석하였다. 임펄스 잡음은 Middleton의 A급 임펄스 환경을 가정하였고, Scatternet에 의한 동일채널 간섭과 라이시안 페이딩을 고려하였다. 임펄스 잡음이 존재하는 블루투스 Scatternet에서 PER (Packet Error Rate)과 ARQ 기법을 적용한 처리율 (Throghput) 향상을 임펄스 파라미터 A와 I'에 따라서 알아 보았다. 시뮬레이션 결과 임펄스 파라미터 A와 I'에 따라 PER 성능에 미치는 영향이 큰 것을 알 수 있었고 SAW-ARQ 방법을 사용하여 성능이 향상됨을 알 수 있었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1233-1236
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• 2002

다수의 Bluetooth 장치가 사용되는 곳에서의 데이터 통신에는 scatternet의 형태가 데이터 전송 효율성에 크게 영향을 미친다. 본 논문에서는 과도한 지연시간을 초래하지 않으면서도장치 간 평균 홉 횟수를 기존 방법보다 감소시킬 수 있는 scatternet 형성 알고리즘을 제시하고 시뮬레이션을 통해 기존 알고리즘과 비교한다.