• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.226-228
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• 2004

IEEE 802.15.3 High-Rate WPAN(Wireless Personal Area Network)는 l0m내외의 무선 환경에서 실시간 비디오, 고품질 오디오 및 대용량 파일 전송을 가능케 하는 기술이다 하나의 네트워크를 piconet 단위로 구성하고 하나의 Piconet에는 PNC(piconet coordinator)가 TOMA(Time Division Multiple Access) 방식으로 DEV(device)들에게 채널타임을 할당한다. 본 논문에서는 IEEE 802.15.3 High-Rate WPAN 환경에서 하나의 piconet 에 존재하는 각각 통신을 하려는 DEV 들이 서로의 신호에 간섭을 받지 않을 만큼 떨어져 있다면 한 개의 채널타임을 각각의 DEV 들에게 동시에 할당하여 여러 DEV들이 동시에 통신을 하는 공간 재활용방식을 통해 네트워크의 성능을 향상하는 방법을 제안하고 MAC의 공간재활용방식을 통한 네트워크의 성능향상 방법을 연구한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1249-1252
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• 2004

IEEE 802.15.3 고속률 WPAN(Wireless Personal Area Networks)은 네트워크 구성 시 인증을 받은 노드들에게만 통신 권한을 부여함으로써 보안성을 높였다. 그러나 IEEE 802.15.3 WPAN에서 제안한 인증 방법은 사전에 각 노드들이 중앙 집중적인 키 관리자로부터 오프라인 상으로 인증키를 분배 받는 것을 가정으로 하고 있다. 이 같은 가정은 WPAN이 무선 Ad Hoc 네트워크로서 중앙 관리 노드가 부재하고 위상 변화가 유동적인 특성을 고려하지 못한 것으로 WPAN의 확장성을 감소시킨다. 따라서 본 논문에서는 WPAN의 노드들이 온라인을 통해 협력적으로 인증키를 생성하는 분산 인증키 관리 방법을 제안한다. 이 방법은 WPAN 네트워크에 확장성을 제공할 뿐 아니라 마스터 노드에 대한 보안 의존성을 감소시켜 인증 서비스의 가용성을 증대시킨다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.3
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• pp.239-246
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• 2013

The IEEE 802.15.4 offers standard about PHY and MAC layer and features low power, low bandwidth, and low speed data communication. Because of this reason, IEEE 802.15.4 is only within a limited range such as sensor detection and home network; nevertheless, the research about transmission multimedia data like voice packet through wireless sensor networks is conducted widely. In this paper, we proposed the group communication system based on the sensor network. TDMA/TDD MAC based on the IEEE 802.15.4 PHY for voice communication on the sensor network is designed by improvement existing peer-to-peer voice communication on the sensor network and hardware is implemented for group communication. To measure the quality of designed system, mean opinion score (MOS) is obtained from the experiment and verified by using sine wave method. As a result of an experiment, we expect that a many cases of application solution can be developed using presented system.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.4
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• pp.26-33
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• 2012

Please WBAN(Wireless Body Area Networks) is wireless communication of within 3 m radius from inside and outside of the body. WBAN is many uses IEEE 802.15.4 MAC protocol for WBAN MAC protocol requirements. IEEE 802.15.4 MAC protocol applies GTS(Guaranteed Time Slot) allocation scheme for guarantee packet delivery of application which requests QoS(Quality of Service). However, GTS allocation scheme of IEEE 802.15.4 MAC protocol uses FIFS(First In First Service) queueing. So it reduces data transmission reliability and has many problems. Therefore, IEEE 802.15.4 applies not WBAN MAC protocol for emergency data transmission. In this paper, we proposes a priority based MAC protocol for emergency data transmission in wireless body area networks. the proposal MAC protocol sets priority the data. So GTS reqeuest throughput of emergency data increasing and GTS allocation delay of emergency data decreasing.

• The KIPS Transactions:PartC
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• v.16C no.3
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• pp.407-416
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• 2009

Recently, various application services in wireless sensor networks are more considered than before, and thus reliable and secure communication of sensor network is turning out as one of essential issues. This paper studies such communication in IEEE 802.15.4 based sensor network. We present IMHRS (IEEE 802.15.4 MAC-based Hybrid hop-by-hop Reliability Scheme) employing EHHR (Enhanced Hop-by-Hop Reliability), which uses Hop-cache and Hop-ack and ALC (Adaptive Link Control), which considers link status and packet type. Also, by selecting security suite depending on network and application type, energy efficiency is considered based on HAS (Hybrid Adaptive Security) Framework. The presented schemes are evaluated by simulations and experiments. Besides, the prototype system is developed and tested to show the potential efficiency.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.216-219
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• 2003

In this paper, we present performance analysis of an IEEE P802.15.3a high rate wireless personal area network transceiver. This physical layer standard uses QOSK as its sub-channel modulation scheme and orthogonal frequency domain modulation (OFDM) for sub-bands. OFDM is used for each sub-band so that multi-path effects are absorbed by equalizer and guard, and fading can be approximately modeled as additive white Gaussian noise. In multi-band ultra-wideband system, DAC quantization error is important noise source since high resolution conversion cannot be used due to high power consumption. Simulation result shows that, to get 640-Mbps throughput, at least 5-bits precision is necessary to maintain bit-error rate under 10$\^$-2/, which can be lowered, with channel coding, to 10$\^$-6/ that is the bit-error rate required by IEEE 802.15 upper protocol layer, in 4-meter LOS fading channel.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.3-6
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• 2009

IEEE 802.15.4 기반의 무선 PAN(WPAN: Wireless Personal Area Network)환경에서 기존에 제안된 전송 전력 제어(TPC: Transmission Power Control) 알고리즘은 수신 신호의 세기를 기반으로 반복 전송을 통하여 적합한 최소 전송 전력을 결정하는 방법으로 진행되어 왔다. 이러한 방법은 통신 채널의 변화가 잦은 지역에서는 재전송률이 높아지고 전송 품질이 떨어지는 단점을 가지고 있다. 따라서 본 논문에서는 IEEE 80215.4에서 제공하는 링크 품질 지표(LQI: Link quality indicator)값을 바탕으로 최소 전송 전력을 결정하여 재전송률을 줄이고, 통신 채널 변화에 보다 능동적으로 대응할 수 있는 새로운 전송 진력 제어 방법을 제안하고자 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.7B
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• pp.892-896
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• 2011

This paper proposes a two-stage synchronization scheme using a serial search non-coherent correlator appropriate for the IEEE 802.15.4a system. The proposed method improved the synchronization performance by using multi-pulse signals unlike the conventional method using single-pulse signals. It also compensated for the degradation of performance at low SNR resulting from the use of fixed threshold by applying the adaptive threshold technique. The proposed method showed a detection probability that is higher by approximately 0.2-0.3 compared with the conventional method in the IEEE 802.15.4a channel model.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.667-669
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• 2004

IEEE 802.15.3 High-Rate WPAN(Wireless Personal Area Network)은 TDMA방식을 사용하며 10m내외에서 멀티미디어와 같은 실시간, 대용량 데이터의 전송을 목적으로 한 기술이다. TDMA방식을 사용하는 기술은 디바이스들이 통신을 하기 전에 미리 채널시간을 할당받아야 한다. IEEE 002.15.3 High-Rate WPAN 환경에서 TCP stream을 전송할 경우 TCP ACK을 전송하기 위해 새로운 채널시간을 할당받아야 한다 송신단은 전송할 데이터와 할당받은 채널시간이 남아있더라도 TCP ACK을 수신할 때까지 아무런 전송도 할 수 없게 된다. 본 논문에서는 High-rate WPAN환경에서 TCP stream을 효과적으로 지원하기 위해 송신단이 할당받은 채널시간동안 송신단과 수신단이 충돌없이 채널을 사용하며 네트워크의 성능을 향상시키는 방법을 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.3
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• pp.1462-1476
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• 2017

The current literature on discrete-time Markov chain (DTMC) based analysis of IEEE 802.15.6 MAC protocols for wireless body area networks (WBANs), do not consider the ACK timeout state, wherein the colliding nodes check the ill fate of their transmissions, while other contending nodes perform backoff check that slot as usual. In this paper, our DTMC model accurately captures the carrier sense multiple access with collision avoidance (CSMA/CA) mechanism of IEEE 802.15.6 medium access control (MAC) and allows the contending nodes performing backoff to utilize the ACK timeout slot during collisions. The compared rigorous results are obtained by considering a non-ideal channel in non-saturation conditions, and CSMA/CA parameters pertaining to UWB PHY of IEEE 802.15.6 MAC protocols.