• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8A
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• pp.613-619
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• 2003

Bluetooth is a communication technology enabling short-range devices to be wirelessly connected. A master and one or more slave devices are connected to form a piconet, and piconets are joined to form a scatternet. The units participating in two or more piconets in a scatternet, is called bridge or gateway nodes. In order to operate the scatternet efficiently, both piconet scheduling for the master and slaves of a piconet, and scatternet scheduling for the bridge nodes are playing important roles. In this paper, we propose a traffic-adaptive dynamic scatternet scheduling algorithm based on rendezvous points and rendezvous windows. The performance of the proposed algorithm is compared and analyzed with that of a static scheduling algorithm via simulations. Simulation results show that our algorithm can distribute wireless resources efficiently to bridge nodes depending on the traffic characteristics.

• The KIPS Transactions:PartC
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• v.11C no.4
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• pp.555-562
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• 2004

We consider differentiated bandwidth allocation for a piconet in short-range wireless personal network systems : Bluetooth. Since bandwidth requirements nay vary among applications/services, and/or it may change over time, it is important to decide how to allocate limited resources to various service classes to meet their service requirements. We propose a simple and efficient bandwidth allocation mechanism which meets bandwidth requirements of various service types while saving power consumption by a Power saying mode, i.e., sniff node. We compare our proposed mechanism with a conventional (weighted) round-robin polling scheme and show that it achieves significant improvement of hroughput, delay, and power consumption.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.187-189
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• 2002

본 논문에서는 효율적인 인터 피코넷 스케줄링 방식과 현재까지 연구된 인트라 피코넷 스케줄링을 인터 퍼코넷 스케줄링으로 적용할 때의 성능을 분석한다. 스캐터넷에서 피코넷 간의 통신이 가능한 블루투스 시뮬레이터를 구현하여 실험하며, 이때 평균 패킷의 전송 지연 시간을 측정하여 각 인터 피코넷 스케줄링의 성능을 분석한다. 비교 분석을 위해 PRR, ERR, LWRR 스케줄링 방범을 블루투스 시뮬레이터에 구현만다. 인트라 피코넷 스케줄링을 PRR, ERR, LWPR 방식으로 동작시킬 때 각각 인터 피코넷 스케줄링으로 PRR, ERR, LWRR을 적용한다. 실험결과는 스니프 모드 사용방식의 PRR을 인터 피코넷 스케줄링으로 적용 할 때 인트라 피코넷 스케줄링에 독립적으로 제일 낮은 평균 패킷 전송지연 시간을 가짐을 보인다.