• Journal of the Korea Society of Computer and Information
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• v.16 no.10
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• pp.73-81
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• 2011

The WBAN(Wireless Body Area Network) technology is a short distance wireless network which provides each device's interactive communication by connecting devices inside and outside of body located within 3 meters. Standardization on the physical layer, data link layer, network layer and application layer is in progress by IEEE 802.15.6 TG BAN. The The WBAN servides consists of both medical and non-medical applications. The medical application service uses the sensor that transfer the periodic traffic and have different data rates. It uses GTS method to guarantee QoS. In this paper, a new method is proposed, which are suitable design for MAC Protocol. Firstly, MAC frame structure and a primitive based on the WBAN are proposed. Secondly, we proposed the GTS algorithm improved the channel utilization based on the WFQ(Weighted Fair Queuing). The proposed scheduling method is improved channel utilization compared with i-Game(Round Robin scheduling method).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.5A
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• pp.290-297
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• 2012

In this paper, we proposed new modulation schemes, Offset Phase Rotation Shift Keying (OPRSK) and Phase Shift Rotation Shift Keying (PSRSK), for medical in-body wireless body area network (WBAN) systems. In IEEE, the WBAN system is assigned as 802.15. Task Group (TG) 6, and the related standardization is being progressed. Recently, in this Group, Phase Silence Shift Keying (PSSK), Phase Silence Position Keying (PSPK) and Phase Rotation Shift Keying (PRSK), which can obtain higher power efficiency, are proposed as new modulation schemes for low-power operation of WBAN system. However, they have a disadvantage for non-linear amplifier distortion. Therefore, in this paper, we proposed OPRSK and PSRSK, which are robust to non-linear amplification, by employing a phase offset in constellation and a power distribution in symbol duration, and verified that the proposed methods have good perfomance and stable operation through performance evaluation.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.5
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• pp.92-105
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• 2015

WBAN (Wireless Body Area Network) is a network which is to consistently monitor body signals with implanted or attached sensor nodes. Especially, nodes that are used in medical services have to operate with low power consumption since they are hard to replace, and have to guarantee high data rate and low transmission delay for consistent signal monitor. In this paper, we propose an algorithm that aims to reduce transmission delay and power consumption, and guarantees stable throughput, by assuming the number of active nodes, and followed by dynamically adjusting the random access period and transmission possibilities in a superframe. The assumed number of active nodes may be incorrect since it only relies on the channel status of a previous superframe. Therefore, we assume the number of active nodes and define a pattern. And revise the number of the active nodes with the defined pattern. To evaluate the performance of the proposed algorithm, we have implemented a WBAN environment with the MATLAB. The simulation results show that the proposed algorithm provides better throughput, low power consumption, and low transmission delay when compared to the slotted ALOHA of the IEEE 802.15.6.

• Information and Communications Magazine
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• v.25 no.2
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• pp.6-10
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• 2008

WBAN(Wireless Body Area Network)은 인체를 기준으로 하여 인체내부 및 인체로부터3미터 이내의 무선통신으로 정의하고 있다. 이에따라 WBAN은 현재 다양한 용도로 응용되고 있는데 크게 분류하면 의료용과 비의료용 무선기기로 구분할 수 있다. 즉 가전기기(Comsumer Electronics)들간 의 통신을 목적으로 하는 비의료용 분야와 인체내부에 이식되어 인체내부의 건강상태에 대한 모니터링이나 인체에 이상이 발생시 대처해 주는 인체이식형 무선기기와 인체외부 3미터 이내에서 의료용 sensor로부터 송수신하는 인체외부 기기로 구분할 수 있다. IEEE802.15.6에서 2006년 하반기부터 WBAN(Wireless Body Area Network)시스템에 대한 표준화를 진행하고 있으며, 2008년도에는 표준 제안서를 각국에서 받아 2009년도에 완료할 예정에 있다. 본 고에서는 기존 WBAN으로 사용하고 있던 무선장비들에 대한 각국의 인체내부와 외부의 주파수 분배동향을 분석한 후 WBAN표준화시 대두될 PHY/MODEM/MAC제안에 결정적 영향을 미치는 WBAN의 주파수에 대한 방향을 제시하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.5
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• pp.315-327
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• 2013

Wireless Body Area Network (WBAN) is a network around a human body within 3~5m which consists of medical or non-medical device. WBAN has to satisfy many kinds of demands such as low-power, a variety of data rate and a data priority. Especially, it is hard for the nodes for monitoring vital signs to replace battery. Thus energy and channel efficiency is important because the battery power is limited. In this thesis, a novel algorithm for reducing the energy consumption is proposed. The proposed algorithm adjusts transmission period according to traffic. by means of determining transmission period by amount of data, the node can reduce energy consumption. Energy detection is performed in order to guarantee data priority before attempting to transmit. In case of failing to transmit, it is proposed that energy consumption is reduced through avoiding collision by changing priority. The comparison result shows that the proposed algorithm reduces power consumption and increasing maximum channel efficiency by avoiding collision.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.6
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• pp.1447-1453
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• 2014

Wireless Body Area Networks (WBAN), standardized as IEEE 802.15.6, enable digital devices on/around the human body to communicate with one another. WBAN is essentially a person's piconet consisting of a master (mobile) device and several slave devices, which follows his/her mobility pattern, and hence, occasionally collides with another piconet as people meet or pass by. As such, a mechanism to detect collision and avoid interference is needed for intra-piconet communications. In this paper, we focus on this notorious problem of piconet collision and propose Distributed Time Division Piconet Coexistence (DTDPC) using local time offset exchange as a simple, attractive solution. The proposed DTDPC provides different level of services for various applications. Besides our simulation results have shown that the proposed solution outperforms the conventional CSMA protocols.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.6A
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• pp.395-404
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• 2012

In general, WBAN environment which use wearable devices on the human body show the different characteristics from other personal area networks. It is usually composed of sensors contacting the body and user terminal collecting the data from the sensors. The sensors are under the significant constraint of the energy resources, but the user terminal is different because it can be recharged and relatively have large energy resources. Under this characteristics, we design a new MAC protocol considering this requirements. The proposed MAC protocol can increase the energy efficiency of sensors and loads the unavoidable energy consumption to the user terminal for high energy efficiency of sensors. Additionally, the proposed MAC protocol provides the low delivery delay of the emergency information for the differentiated QoS because the emergency data requires more rapid transmission than the periodic sensed data. For this requirement, we employ the IFS (Inter Frame Space). For the efficient and objective evaluation of the proposed MAC protocol, IEEE 802.15.6 MAC is used to compare with it and we show that the advantage of the proposed MAC meet our expectation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.2
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• pp.323-335
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• 2015

Mobile healthcare is a fusion of information technology and biotechnology and is a new type of health management service to keep people's health at anytime and anywhere without regard to time and space. The WBAN(Wireless Body Area Network) technology that collects bio signals and the data analysis and monitoring technology using mobile devices are essential for serving mobile healthcare. WBAN consisting of users with mobile devices meet another WBAN during movement, WBANs transmit data to the other media. Because of WBAN conflict, several nodes transmit data in same time slot so a collision will occur, resulting in the data transmission being failed and need more energy for re-transmission. In this thesis, we proposed a MAC protocol for WBAN with mobility to solve these problems. First, we proposed a superframe structure for WBAN. The proposed superframe consists of a TDMA(Time Division Muliple Access) based contention access phase with which a node can transmit data in its own time slot and a contention phase using CSMA/CA algorithm. Second, we proposed a network merging algorithm for conflicting WBAN based on the proposed MAC protocol. When a WBAN with mobility conflicts with other WBAN, data frame collision is reduced through network reestablishment. Simulations are performed using a Castalia based on the OMNeT++ network simulation framework to estimate the performance of the proposed superframe and algorithms. We estimated the performance of WBAN based on the proposed MAC protocol by comparing the performance of the WBAN based on IEEE 802.15.6. Performance evaluation results show that the packet transmission success rate and energy efficiency are improved by reducing the probability of collision using the proposed MAC protocol.

• Information and Communications Magazine
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• v.25 no.2
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• pp.26-31
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• 2008

WLAN, WPAN 기술에 이어 최근에는 인체영역에서의 의료용/비의료용 통신을 위한 무선 기술인 Wireless Body Network (WBAN)이 주목을 받고 있다. 이러한 추세에 따라 IEEE 802.15.6을 비롯한 여러 표준화 단체에서 인체영역의 무선 전송 기술 표준제정을 위해 활발한 활동을 벌이고 있다. 본 고에서는 이러한 인체영역 무선통신 기술의 표준화 동향과 MAC프로토콜 설계 시 고려해야 할 사항 및 적용 가능한 기법에 대해 살펴본다.

• Journal of Digital Contents Society
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• v.15 no.6
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• pp.663-673
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• 2014

The WBAN technology means a short distance wireless network which provides each device interactive communication by connecting devices inside and outside of body. Standardization on the physical layer, data link layer, network layer and application layer is in progress by IEEE 802.15.6 TG BAN. Wireless body area network is usually configured in energy efficient using sensor and zigbee device due to the power limitation and the characteristics of human body. Wireless sensor network consist of sensor field and sink node. Sensor field are composed a lot of sensor node and sink node collect sensing data. Wireless sensor network has capacity of the self constitution by protocol where placed in large area without fixed position. In this paper, we proposed the efficient addressing scheme for improving the performance of routing algorithm by using ZigBee in WBAN environment. A distributed address allocation scheme used an existing algorithm that has wasted in address space. Therefore proposing x, y and z coordinate axes from divided address space of 16 bit to solve this problems. Each node was reduced not only bitwise but also multi hop using the coordinate axes while routing than Cskip algorithm. I compared the performance between the standard and the proposed mechanism through the numerical analysis. Simulation verified performance about decrease averaging multi hop count that compare proposing algorithm and another. The numerical analysis results show that proposed algorithm reduced the multi hop better than ZigBee distributed address assignment