• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
• /
• pp.276-278
• /
• 2005

This paper introduces the testbed configuration for telematics wireless communications using WiBro network, one of the next generation wireless communication networks. We review the architecture and core technology of WiBro network, and investigate WiBro based telematics services, WiBro testbed configuration, and function verification and test method for WiBro wireless communication access module.

• Journal of Information Processing Systems
• /
• 제19권2호
• /
• pp.211-218
• /
• 2023

In order to improve the low accuracy of traditional wireless network health information retrieval methods, a wireless network health information retrieval method is designed based on data mining algorithm. The invalid health information stored in wireless network is filtered by data mapping, and the health information is clustered by data mining algorithm. On this basis, the high-frequency words of health information are classified to realize wireless network health information retrieval. The experimental results show that exactitude of design way is significantly higher than that of the traditional method, which can solve the problem of low accuracy of the traditional wireless network health information retrieval method.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 2006년도 추계학술대회 학술발표 논문집 제16권 제2호
• /
• pp.289-292
• /
• 2006

In this paper, a wireless control network based on IEEE 802.15.4 MAC protocol is proposed. The superframe of IEEE 802.15.4 is applied to the proposed wireless control network. The transmission and bandwidth management method are proposed for efficient transmission in the superframe. By these methods, the proposed wireless control network protocol is able to transmit three types of data (periodic data, sporadic data, and non real-time message), and guarantee real-time transmission within deadline.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제7권4호
• /
• pp.800-818
• /
• 2013

Supporting video streaming over multi-hop wireless networks is particularly challenging due to the time-varying and error-prone characteristics of the wireless channel. In this paper, we propose a joint optimization scheme for video streaming over multi-hop wireless networks. Our coding scheme, called Joint Source/Network Coding (JSNC), combines source coding and network coding to maximize the video quality under the limited wireless resources and coding constraints. JSNC segments the streaming data into generations at the source node and exploits the intra-session coding on both the source and the intermediate nodes. The size of the generation and the level of redundancy influence the streaming performance significantly and need to be determined carefully. We formulate the problem as an optimization problem with the objective of minimizing the end-to-end distortion by jointly considering the generation size and the coding redundancy. The simulation results demonstrate that, with the appropriate generation size and coding redundancy, the JSNC scheme can achieve an optimal performance for video streaming over multi-hop wireless networks.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제8권4호
• /
• pp.1390-1405
• /
• 2014

This paper investigates optimal relay selection and power allocation under an aggregate power constraint for cooperative wireless sensor networks assisted by amplify-and-forward relay nodes. By considering both transmission power and circuit power consumptions, the received signal-to-noise ratio (SNR) at the destination node is calculated, based on which, a relay selection and power allocation scheme is developed. The core idea is to adaptively adjust the selected relays and their transmission power to maximize the received SNR according to the channel state information. The proposed scheme is derived by recasting the optimization problem into a three-layered problem-determining the number of relays to be activated, selecting the active relays, and performing power allocation among the selected relays. Monte Carlo simulation results demonstrate that the proposed scheme provides a higher received SNR and a lower bit error rate as compared to the average power allocation scheme.

• 한국위성정보통신학회논문지
• /
• 제9권1호
• /
• pp.45-50
• /
• 2014

본 논문에서는 한 도시(원주시)를 대상으로 안정적이면서 높은 경제 절감 효과를 얻을 수 있는 광대역 무선 Smart-city형 네트워크 커버리지를 제안하고자 한다. 이를 위하여 해당 지역에 대한 사전 지리적 조사를 실시하고 환경에 적합한 장비를 선택하여 네트워크망의 추가 및 복구가 쉬운 무선 메쉬 네트워크망을 설계하였고 시뮬레이션을 통해 기존에 구축되어 있는 네트워크망과 그 성능을 비교, 평가하고 고찰하였다. 본 논문이 추구하는 목표는 연구를 통해 무선 메쉬 네트워크의 경비 절감 효과 및 우수한 성능을 평가받고 이를 활용하여 그린 IT의 기초가 될 수 있는 미래지향적 도심 통합 네트워크를 제안하는데 있다.

• Journal of information and communication convergence engineering
• /
• 제4권2호
• /
• pp.67-70
• /
• 2006

A distributed healthcare monitoring system prototype for clinical and trauma patients was developed, using wireless sensor network node. The proposed system aimed to measure various vital physiological health parameters like ECG and body temperature of patients and elderly persons, and transfer his/her health status wirelessly in Ad-hoc network to remote base station which was connected to doctor's PDA/PC or to a hospital's main Server using wireless sensor node. The system also aims to save the cost of healthcare facility for patients and the operating power of the system because sensor network is deployed widely and the distance from sensor to base station was shorter than in general centralized system. The wireless data communication will follow IEEE 802.15.4 frequency communication with ad-hoc routing thus enabling every motes attached to patients, to form a wireless data network to send data to base-station, providing mobility and convenience to the users in home environment.

• 한국산업정보학회논문지
• /
• 제22권1호
• /
• pp.1-9
• /
• 2017

무선 네트워크 기술과 무선 전송 기술의 발전으로 인해 무선 전달망(Wireless Transit Network) 구성 기술로서 무선 메시 네트워크(WMN)가 관심을 받고 있다. 오랜 기간 다양한 영역에서 WMN에 대한 연구가 진행되었지만 아직 해결되지 않은 문제들이 많이 남아있다. 그 중 하나가 무선 링크로 구성된 다중 홉 네트워크에서 최적 경로를 찾는 라우팅 문제이다. WMN의 3가지 구성유형 중 하나인 하이브리드 WMN에서 최적 경로 선택을 위해서는 우수한 성능의 메트릭 연구와 함께 효과적으로 인프라스트럭처 메시를 전달망으로 사용하기 위한 경로 검색 프로토콜 연구가 필요하다. 따라서 본 논문에서는 하이브리드 WMN을 위한 듀얼모드-AODV(Ad hoc On-demand Distance Vector)를 제안한다. 본 논문에서 제안된 듀얼모드-AODV를 하이브리드 WMN에 적용하는 경우 AODV에 비하여 경로 검색 지연시간이 52% 감소하는 것을 시뮬레이션을 통해 확인하였다.

• 한국군사과학기술학회지
• /
• 제18권4호
• /
• pp.423-431
• /
• 2015

A leased line modem usability was evaluated and investigated in the wireless internet protocol(IP) network. The signal of the modem in the circuit switching network was translated to IP packet by using several voice codecs (PCM, G.711A, $G.711{\mu}$, and etc.) and transmitted through the wireless IP network. The wireless IP network was simulated by the Tactical information and communication network Modeling and simulation Software(TMS). The performance and usability of the leased line modem are simulated using the system-in-the-loop(SITL) function of TMS with respect to packet delay, jitter, packet discard ratio, codecs, and wireless link BER.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
• /
• pp.476-479
• /
• 2003

Recently, Bluetooth has been regarded as a new technology for short-range wireless connection. Although initial application of Bluetooth technology has been focused mainly on replacing cables between hand-held devices due to a limited packet size and short-range, general wireless telecommunication such as PAN and Ad hoc networks via Bluetooth-equipped devices is expected to be one of the most popular applications. Wireless equipments have been used to exchange data between host and mobile unit. The exchanging data may be several bytes of control command and the value of sensors with ultra-sonic, vision sensor, and encoder from mobile robot. However, most wireless equipments have some drawbacks such as lack of authentication, large size and high price. On the other hand, the benefits of Bluetooth are small size, low power, low price except short-range. Especially, there are some difficulties when wireless modules are used in indoor environments. In this paper, a method of using wire network in Bluetooth network is investigated as a solution to overcome the short-range problem of Bluetooth and difficulty in indoor environment.