• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.868-870
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• 2001

본 논문에서는 WPAN(Wireless Personal Area Network)의 종단 사용자 기기의 한계적 계산 능력 및 무선 링크의 대역폭과 기존 외부 네크워크와의 연결을 고려하여 선택적 신뢰 기관(Trusted Third Party. TTP) 서비스를 수용한 보안 관리 서비스 프로토콜을 제안하였다. 제안한 서비스는 종단 사용자 기기의 한계적 능력에 대해 해당 내부 네트워크의 TTP와 공개키를 기반으로 인증 서비스를 수행하도록 하였으며, 이후 종단 사용자는 해당 인증 결과를 기반으로 외부 네트워크의 전자 상거래 주체와의 상호 메시지 교환을 위한 보안 관리 서비스 프로토콜을 수행하도록 하였다. 또한 사전에 외부 네트워크에 대한 전자 상거래 서비스 요청에 한하여 TTP의 부분적 서비스를 수행하도록 허용하여 시스템의 대단위 계산 능력에 대한 효율성을 보장할 수 있다.

• Journal of information and communication convergence engineering
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• v.9 no.4
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• pp.405-410
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• 2011

In this paper, a conflict-avoided resource reservation scheme for UWB (Ultra Wide Band) WPAN (Wireless Personal Area Network) with D-MAC (Distributed Medium Access Control) is proposed. Since distributed characteristic of the WiMedia D-MAC supporting DRP (Distributed Reservation Protocol) scheme may cause lots of conflicts, overall performances of the WiMedia D-MAC can be deteriorated. In addition, once a DRP conflict occurs, only one of the DRP reservations involved in that DRP conflict maintains the reserved MASs, while the other DRP reservation must be terminated and DRP negotiations for them have to be re-started. Such DRP termination and renegotiation time delays due to the DRP conflicts can be a critical problem to the mobile devices transceiving real-time QoS traffic streams. Therefore, we propose a mechanism to avoid DRP conflicts by providing a kind of path diversity using relay transmission scheme and demonstrate its performance improvements via simulation results.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1363-1365
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• 2009

현대 사회에서 유비쿼터스 센서 네트워크 환경을 제공하기 위해 활발한 활동이 이루어지고 있다. LR-WPAN 기술인 IEEE802.15.4가 표준화 되면서 유비쿼터스 센서 네트워크의 중심 기술로 자리 매김하게 되었다. IEEE802.15 표준은 WPAN(Wireless Personal Area Network) 즉, 비교적 짧은 거리에서 휴대하여 이동할 수 있는 장치들이 근처의 다른 장치들과 통신이 가능하도록 만든 무선 네트워크 통신 표준이다. 이러한 IEEE802.15 표준들은 PHY와 MAC에 대해서만 표준을 정의 하고 있다. 센서 네트워크에서 가장 중요한 이슈중의 하나는 제한된 자원 즉, 센서 노드에 주어진 에너지를 활용하여 네트워크의 수명을 최대로 연장 하는 것이다. 본 논문에서는 NS-2 시뮬레이션을 통해 WPAN에서 노드의 전송거리에 따른 에너지 효율을 분석한다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.10
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• pp.35-42
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• 2011

WPAN(Wireless Personal Area Network) have many advantages such as using low power and cheap price, small size. So it is recently increasing application range such as personal portable device, home network and sensor network so and on. IEEE 802.15.3 basically has the point to point or peer to peer UM(Usage Model). But using devises that need data transmission is increasing in the house and office. Therefor UM of point to multipoint is proposed. In this paper, I proposed Multicast ACK mechanism on the point to multipoint UM. So it is able to transfer data to multiple devices as this Multicast transfer method at a time. Thus, throughput performance is improved. But the problem that increases data transfer delay is appeared because of adding Multicast ACK traffic. We compared the performance between standard and proposed mechanism through a numerical analysis.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.20-28
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• 2007

Zigbee sensor network base on IEEE802.15.4 has local address of 2 byte on transmit packet data which is pick up the address for each sensor node. Sensor network is requested low power, low cost, many nodes at hues physical area. There for Zigbee is very good solution supporting for next Ubiquitous generation but the Zigbee sensor network has address allocation problem of each sensor node. Is established standard from Zigbee Alliance, to the address allocation method uses Cskip algorithm. The Cskip algorithm use the hazard which allocates an address must blow Hop of the maximum modification and child node number. There is to address allocation and from theoretically it will be able to compose a personal 65536 sensor nodes only actual with concept or space, only 500 degree will be able to compose expansion or the low Zigbee network. We proposed an address allocation method using coordinate value for Zigbee sensor network.

• Journal of Korea Multimedia Society
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• v.19 no.12
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• pp.1981-1991
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• 2016

In recent, the advancement of wearable devices and wireless body area networking technologies motivate researchers to pay attention to remote healthcare system for monitoring patients health and disease progression effectively. However, in order to implement a practical remote healthcare system, we must consider the security and privacy of patient's personal health information transmitted to healthcare servers through the network. Hence, in this paper, we propose a secure health data transmission protocol in remote healthcare monitoring system to protect patient's health information and prevent privacy from eavesdropping on the network. To achieve our security goals, we design an efficient secure protocol based on the identity-based cryptography with key evolution technique, and then confirm the superiority and the efficiency of the proposed protocol as compared with the existing protocol of Yang et al.

• Journal of KIISE:Information Networking
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• v.34 no.3
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• pp.175-185
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• 2007

In IEEE 802.15.4 (Low-Rate Wireless Personal Area Network) specification, a successful reception and validation of a data or MAC command frame can be confirmed with an acknowledgment. However, the specification does not support security for acknowledgment frame; the lack of a MAC covering acknowledgments allows an adversary to forge an acknowledgment for any frame. This paper proposes an identity authentication mechanism at the link layer for acknowledgment frame in IEEE 802.15.4 network. With the proposed mechanism there is only three bits for authentication, which can greatly reduce overhead of device. The encrypted bit stream for identity authentication will be transmitted to device by coordinator within association process. Statistical method and simulation results prove that our mechanism is successful in handling MAC layer attack.

• The KIPS Transactions:PartC
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• v.11C no.3
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• pp.395-400
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• 2004

Being aware of growing needs for wireless communication led to the development of UWB systems, this study proposed an impulse for single band UWB systems which does not count a carrier; analyzed the characteristics and the problems of pulses suggested by the existing poise of the Un system; finally, proposed TDMG(Time Delay Multiple Gaussian) pulse that generates signals of UWB without attenuation of pulse width. The hardware structure of the TDMC pulse for the single band UWB system was modelled after describing the pulse in a mathematical method in an attempt to compare with performances of the existing pulses through computer simulation. The outcome of the test unveiled the fact that each center frequency of the TDMG pulse rose approximately 1GHz, and also each l0dB fractional bandwidth of the TDMG pulse was widened over 1GHz. In the case of derivative, center frequencies of the TDMG pulse rose over 1GHz each. As a consequence, the TDMG pulse appeared to have better quality frequency, satisfying the characteristics of spectrum and the band of frequency recommended by the FCC and decreasing interference with other wireless communication systems.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.8
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• pp.1349-1355
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• 2008

Recently many short-range transceiver systems, such as ZigBee, Bluetooth and RFID(Radio Frequency Identification), have been developed. These systems are mostly low-power transceivers. In the near future many more low-power transceivers are appeared for WPAN(Wireless Personal Area Network) and interference mitigation technologies are necessary to the low-power transceivers for using frequency resources efficiently. In this paper we consider two methods for sharing frequency resources. The first case is that a frequency band previously assigned fer a certain system is shared and the second case is that the white frequency band is shared. We study the method and conditions for sharing frequency resources in the above two cases. When a frequency band is shared with ZigBee, RFID, DCP (Digital Cordless Phone) and Bluetooth as an example for the first case, the sharing conditions are investigated and the results are presented. We propose a balancing factor to maintain an equal transmitting conditions between systems having a different interference mitigation technique. In the interference simulation we use FH(Frequency Hopping) as a reference system and 0.9 of a balancing factor for LBT(Listen Before Talk) and 0.8 for DS(Direct Spreading). From the simulation results we know that a balancing factor reduces interference probability therefore many more systems can be operated in the same frequency bands compared with the case without using a balancing factor.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.6B
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• pp.350-357
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• 2007

The IEEE 802.15.3 high-rate WPAN has been developed to communicate with devices within l0m. A piconet consists of one Piconet Coordinator (PNC) and several devices. The devices associated with a parent piconet can become child PNCs in order to form child piconets. A mesh network made up of a parent piconet and several child piconets can support multi-hop communications. In this paper, we analyze the maximum level and the avaliable superframe size to make the best use of bandwidth for multi-hop communications, and compare the analysis with the simulation results in terms of time to discover devices for multi-hop communications. The average number of levels in mesh networks is shown to be about 1.9 when the number of devices increases within a fixed area. We have also shown that the maximum available superframe size is 52ms and the discovery time is approximately 155ms.