• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.345-348
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• 2004

Every bridge node participating in multiple piconets and forming a scatternet should schedule the inter-piconet traffics in an efficient manner. Frequent piconet switching due to short polling intervals for the links of a bridge node leads to considerable time slots loss caused by the guard time and power consumption for transceiving and processing. On the other hand, restrained piconet switching may result in failures of fulfilling QoS (Quality of Service) requirements for some links. Tn this paper, we present a QoS aware inter-piconet scheduling scheme minimizing the piconet switching events within guaranteed QoS requirements. According to simulation results, the proposed scheme is confirmed to have great improvement in throughput and number of switching events over the credit scheme as current inter-piconet scheduling scheme for the scatter mode.

• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.38-47
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• 2003

Communication between Bluetooth devices is based on TDD by a master unit. In this discipline, the transmission of slave packets can be made only when the master transmits a packet to the slave. Thus, some slots may be wasted when there is no user data in the master's or slave's queue due to the transmission of a POLL or NULL packet. Therefore a scheduling scheme which can minimize the slot waste is required in Bluetooth intra-piconet communication. However, since the master is responsible for the intra-piconet scheduling, it must be provided with an information on each slave's queue length to apply traditional scheduling schemes. which is impossible in Bluetooth. This paper presents a new Bluetooth intra-piconet scheduling scheme that is efficient and does not require the information on each slave's queue length. The scheduling is done based on the information about the existence of data in the master and slave queues which is derived by the master identifying the type of packets transmitted. The master schedules to communicate with the slaves according to the priorities determined based on this information. We Presents simulation results which indicate a significant improvement in the performance when our proposed scheme is used.

• 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.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 Communications and Networks
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• v.9 no.3
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• pp.229-235
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• 2007

This paper analyzes the performance of a Bluetooth piconet in error-prone environments. A statistical characterization of a waiting time, an end-to-end delay, and a goodput are derived analytically in terms of the arrival rates, the number of slaves, and the packet error rate (PER). For simplicity, half-symmetric piconet is assumed in this analysis. Both exhaustive and limited scheduling are considered. The analytic results are validated by simulations.

• 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.

• 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

• Journal of the Semiconductor & Display Technology
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• v.12 no.4
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• pp.1-7
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• 2013

This paper presents the AMR (Automatic Meter Reading) system using the binary CDMA (Code Division Multiple Access) radio technology. The binary CDMA is the new radio technology in domestic research. Main implementation topics includes the binary CDMA remote meter reading system, the wireless piconet configuration for the wireless automatic meter reading, and the transmission scheduling for sending and receiving data. Also, the wireless packet data encryption is very important topics for the wireless automatic meter reading. The proposed AMR system is implemented as a pilot project in Jeju and Gangwon. It can be seen that the wireless remote reading using the binary CDMA wireless technology can be applied to the AMR system.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.4
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• pp.239-244
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• 2012

In this paper, we first introduce our own binary CDMA technology. Then we propose a wireless distribution automation system using the binary CDMA technology. The major research items are the binary CDMA distribution automation system, piconet configuration for remote control and monitoring, scheduling for the transmission and reception of data, and ways of applying encryption to protect wireless packet. To verify the possibility of applying wireless transmission to the distribution automation system, we experiment the implemented system in terms of the transmission rate by applying it to a real-world environment.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.414-417
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• 2003

In this paper, a performance of Bluetooth piconet is analyzed. Average cycle time, average waiting time, average transfer delay and average queue length are used for measure of performance (MOP). Simple round robin (RR) scheduling policy with exhaustive service is used for the analysis. Packet loss is considered because of noise environments of wireless communication. Numerical results have been presented. Simulation is performed to validate the correctness of analysis.y and its maximum operating frequency is 800MHz.