• Journal of information and communication convergence engineering
• /
• 제9권5호
• /
• pp.562-566
• /
• 2011

As telecommunication technologies in telemedicine services are developed, the expeditious development of wireless and mobile networks has stimulated wide applications of mobile electronic healthcare systems. However, security is an essential system requirement since many patients have privacy concerns when it comes to releasing their personal information over the open wireless channels. Due to the invisible feature of mobile signals, hackers have easier access to hospital networks than wired network systems. This may result in several security incidents unless security protocols are well prepared. In this paper, we analyzed authentication and authorization procedures for healthcare system architecture to apply secure M-health systems in the hospital environment. From the analyses, we estimate optimal requirements as a countermeasure to its vulnerabilities.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제5권9호
• /
• pp.1528-1543
• /
• 2011

With increasing the using of wireless technologies in essential fields such as the medical application, this paper proposes different scenarios for the transmission of images over wireless networks. The paper uses the IEEE ZigBee 802.15.4 for applying the proposed schemes. It is a Wireless Personal Area Network (WPAN). This paper presents a novel chaotic interleaving scheme against error bursts. Also, the paper studies the proposed interleaver with the convolutional code with different constraint lengths (K). A comparison study between the standard scheme and proposed schemes for image transmission over a correlated fading channel is presented. The simulation results show the superiority of the proposed chaotic interleaving scheme over the traditional schemes. Also, the chaotic interleaver packet-by-packet basis gives a high quality image with (K=3) and reduces the need for the complex encoder with K=7.

• 한국통신학회논문지
• /
• 제40권11호
• /
• pp.2178-2187
• /
• 2015

무선 개인화 네트워크 환경에서는 통신 장치의 경량화 정책으로 인하여 에너지 효율이 크게 요구되며, 이러한 시장 요구를 만족시키기 위하여 수많은 통신 프로토콜들이 연구되어 왔다. 특히 Bluetooth Low Energy 기술은 Duty Cycle 방식과 주파수 호핑 방식을 모두 채택하여 저전력 통신 기술의 대표 기술로 시장 선점을 주도하고 있다. 하지만 대부분의 저전력 통신 기술들은 Duty Cycle 채택 등의 이유로 Broadcast 통신 방식에서의 신뢰성 문제를 해결하기 힘들다. 본 논문에서는 IoT 환경에서 발생될 수 있는 Broadcast 통신 요구를 Bluetooth Low Energy 환경에서 해결하기 위한 에너지 고효율의 MAC 프로토콜을 제안하고, Master 장치와 Slave 장치의 Broadcast 전송 효율에 대한 분석을 통하여 제안 방식의 객관적 성능을 검증한다.

• Journal of Communications and Networks
• /
• 제16권1호
• /
• pp.36-44
• /
• 2014

Exploiting the energy-delay tradeoff for energy saving is critical for developing green wireless communication systems. In this paper, we investigate the delay-constrained energy-efficient packet transmission. We aim to minimize the energy consumption of multiple randomly arrived packets in an additive white Gaussian noise channel subject to individual packet delay constraints, by taking into account the practical on-off circuit power consumption at the transmitter. First, we consider the offline case, by assuming that the full packet arrival information is known a priori at the transmitter, and formulate the energy minimization problem as a non-convex optimization problem. By exploiting the specific problem structure, we propose an efficient scheduling algorithm to obtain the globally optimal solution. It is shown that the optimal solution consists of two types of scheduling intervals, namely "selected-off" and "always-on" intervals, which correspond to bits-per-joule energy efficiency maximization and "lazy scheduling" rate allocation, respectively. Next, we consider the practical online case where only causal packet arrival information is available. Inspired by the optimal offline solution, we propose a new online scheme. It is shown by simulations that the proposed online scheme has a comparable performance with the optimal offline one and outperforms the design without considering on-off circuit power as well as the other heuristically designed online schemes.

• 한국언론정보학보
• /
• 제39권
• /
• pp.506-543
• /
• 2007

본 연구는 문화 간 커뮤니케이션(intercultural communication) 관점에서 국가명성과 문화, 그리고 커뮤니케이션 간 관련성을 연구하였다. 연구대상으로 한국 거주 서구인 18명을 심층적으로 인터뷰하였으며 한국에 대한 이미지, 국가명성 구성요인과 커뮤니케이션 경로, 한국에 대한 호의적/비호의적 태도와 이유 등을 질문했다. 심층인터뷰 분석결과, 문화동화와 문화 간 커뮤니케이션은 국가명성과 매우 밀접한 연관성을 갖는 것으로 분석되었다. 한국에 대한 정보를 수집하기 시작하면서 자신의 문화적 정체성과 한국의 정체성 간의 갈등(conflict)이 발생하면서 분리유형과 통합유형, 동화유형으로 구분되는데, 문화동화유형별로 다른 정보를 수집하고 다른 커뮤니케이션 네트워크를 활용하면서 한국에 대한 대응전략과 태도를 달리하게 된다. 특히 동화유형은 '내집단 기대(in-group expectancy)'가 충족되면서 한국에 대한 로열티를 형성하게 된다. 이들의 커뮤니케이션 네트워크는 한국인 동료나 친구, 친지로 구성된 '내집단 공동체 네트워크(in-group community network)'이며, 보다 은밀하고 깊숙한 정보를 교환하게 된다. 특히 명성 차원에서는 한국에 대한 기대된 정체성(desired identity)과 전달된 정체성(communicated identity), 그리고 인지된 정체성(conceived identity) 모두가 일치하기 때문에 한국의 강점이 명성으로 구축되는 단계이기도 하다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 제39회 하계학술대회
• /
• pp.2269-2270
• /
• 2008

Zigbee that is the wireless personal area networks communication technology for low power consumption is low-cost, low-power consumption, and small size and program code. From the present paper symbol and chip sequence of existing Zigbee module undergarment PN code generators which are a 1:1 mapping method it uses shift register and it plans the method which it proposes. The experimental result used Xilinx ISE and it measured synthesis and timing and power.

• Advances in aircraft and spacecraft science
• /
• 제9권6호
• /
• pp.525-536
• /
• 2022

The current state of telecommunications infrastructure in the Arctic does not allow providing a wide range of required services for people, businesses and other categories, which necessitates the use of non-traditional approaches to its organization. The paper proposes an innovative approach to building a combined communication network based on tethered high-altitude platform station (HAPS) located at an altitude of 1-7 km and connected via radio channels with terrestrial and satellite communication networks. Network configuration and composition of telecommunication equipment placed on HAPS and located on the terrestrial and satellite segment of the network was justified. The availability of modern equipment and the distributed structure of such an integrated network will allow, unlike existing networks (Iridium, Gonets, etc.), to organize personal mobile communications, data transmission and broadband Internet up to 100 Mbps access for mobile and fixed subscribers, rapid transmission of information from Internet of Things (IoT) sensors and unmanned aerial vehicles (UAV). A substantiation of the possibility of achieving high network capacity in various paths is presented: inter-platform radio links, subscriber radio links, HAPS feeder lines - terrestrial network gateway, HAPS radio links - satellite retransmitter (SR), etc. The economic efficiency of the proposed solution is assessed.

• 한국통신학회:학술대회논문집
• /
• 한국통신학회 2004년도 추계종합학술대회 논문 초록집
• /
• pp.179-179
• /
• 2004

• ETRI Journal
• /
• 제32권5호
• /
• pp.713-721
• /
• 2010

E-textile technology has earned a great deal of interest in many fields; however, existing wearable network protocols are not optimized for use with conductive yarn. In this paper, some of the basic properties of conductive textiles and requirements on wearable personal area networks (PANs) are reviewed. Then, we present a wearable personal network (WPN), which is a four-layered wearable PAN using bus topology. We have designed the WPN to be a lightweight protocol to work with a variety of microcontrollers. The profile layer is provided to make the application development process easy. The data link layer exchanges frames in a master-slave manner in either the reliable or best-effort mode. The lower part of the data link layer and the physical layer of WPN are made of a fabric serial-bus interface which is capable of measuring bus signal properties and adapting to medium variation. After a formal verification of operation and performances of WPN, we implemented WPN communication modules (WCMs) on small flexible printed circuit boards. In order to demonstrate the behavior of our WPN on a textile, we designed a WPN tutorial shirt prototype using implemented WCMs and conductive yarn.

• 전자공학회논문지CI
• /
• 제44권3호
• /
• pp.49-56
• /
• 2007

IEEE 802.15.4 저속 무선 개인 통신망(low rate wireless personal area network)은 유비쿼터스 센서네트워크를 구성하는데에 적합한 프로토콜이다. 그러므로, 최근에 다양한 응용네트워크에서 IEEE 802.15.4 프로토콜에 대한 관심이 증대하고 있다. 본 논문에서는 실시간 트래픽 처리를 위하여 보장 시간 슬롯(Guaranteed time slots, GTS)을 할당하며, 이러한 할당방식을 적용시에 IEEE 802.15.4 프레임 및 부프레임과 관련된 최적의 파라미터들을 획득하는 방법을 제안한다. 네트워크에 있는 각 노드에 할당된 대역폭과 주기값에 대한 요구사항들이 주어질 때, 이들 요구사항들을 만족시키는 비콘 주기(beacon period)와 활성/비활성 부프레임 시간들의 후보들을 선택하고, 이들 중 가장 낮은 듀티 사이클(duty cycle)을 낼 수 있는 파라미터를 선택한다. 이들 최적 파라미터를 기반으로 하여 본 논문의 분석 결과는 소모전력 절약을 포함한 네트워크 자원을 효율적으로 이용할 수 있는 방식을 제공한다.