• Smart Structures and Systems
• /
• v.5 no.2
• /
• pp.119-137
• /
• 2009

Smart sensors densely distributed over structures can use their computational and wireless communication capabilities to provide rich information for structural health monitoring (SHM). Though smart sensor technology has seen substantial advances during recent years, implementation of smart sensors on full-scale structures has been limited. Hardware resources available on smart sensors restrict data acquisition capabilities; intrinsic to these wireless systems are packet loss, data synchronization errors, and relatively slow communication speeds. This paper addresses these issues under the hardware limitation by developing corresponding middleware services. The reliable communication service requires only a few acknowledgement packets to compensate for packet loss. The synchronized sensing service employs a resampling approach leaving the need for strict control of sensing timing. The data aggregation service makes use of application specific knowledge and distributed computing to suppress data transfer requirements. These middleware services are implemented on the Imote2 smart sensor platform, and their efficacy demonstrated experimentally.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.3 no.1
• /
• pp.75-82
• /
• 1999

This paper describes the implementation of wireless realtime monitoring system using modified CSMA/CA protocol. This system consists of wireless modem, central monitor, mobile station, DB server, and offer advantage of mobility, reduced installation time, long-term cost savings, and so on. And this system offers patient position pursuit service. Patient position pursuit service must be offered to deal with emergency which can be occured during patient movement. This paper proposes modified CSMA/CA protocol and patient position pursuit algorithm, implements wireless realtime monitoring system using it.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.8 no.6
• /
• pp.165-172
• /
• 2008

The decisive factor for the popularization of telematics services in the future isn the ability to produce advanced service that match the needs of drivers and passengers. The Dedicated Short Range Communication(DSRC)-type of wireless communication system, which is being developed for the Intelligent Transport System(ITS), is one of the broadband wireless systems contributing to the improvement of driver and passenger needs, such as convenience, entertainment, comfort and safety. In this paper, the possibility of applying this system to the traffic information collection service will be explored. Further, a description of the service design for the traffic information collection system using electronic toll collection service will be provided, in the knowledge that the existence of information communication equipment mounted vehicles will remain.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.3
• /
• pp.542-547
• /
• 2018

Various countries around the world are conducting various studies to apply information and communication technology to marine safety. Based on this, the International Maritime Organization (IMO) has established the e-Navigation standard to apply the latest information and communication technology to marine services. In Korea, the Ministry of Maritime Affairs and Fisheries is promoting Korean e-navigation considering domestic marine environment and is trying to apply LTE communication method as a high-speed wireless communication method at sea. In this paper, we describe the development of an LTE based marine router system supporting 700Mhz frequency band allocated for high speed maritime wireless communication service. Experiments on the possibility of 100km distance communication from base station using LTE based ship router are shown. LTE - based high - speed maritime wireless communication router system can provide communication infrastructure necessary to develop various accident prevention technologies that may occur at sea.

• ETRI Journal
• /
• v.28 no.2
• /
• pp.205-215
• /
• 2006

Wireless data communication (WDC) services are increasingly penetrating the market. The two main alternative WDC technologies are wireless LAN and mobile Internet. Services based on these technologies display differences in quality attributes such as terminal device, data transmission speed, pricing scheme and so on. How consumers choose between these two alternatives will be determined by their preferences regarding such quality attributes. In turn, their preferences will affect the evolution of WDC services and related technologies. This study employs a conjoint analysis of consumer valuations of quality attributes of wireless LAN and mobile Internet services. Respondents rate hypothetical service alternatives featuring various combinations of quality attributes. By estimating consumer willingness to pay for the attributes of WDC services, the authors predict the evolution of WDC services and related technologies along various quality dimensions, make a comparison with the results of a previous study, and draw policy implications for national-and company-level R&D strategies.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.9 no.6
• /
• pp.719-726
• /
• 2014

This paper addresses quality of experience(QoE) and how to measure and evaluate QoE including its subjective aspects. Adopting the real measurements on the field, a various quality metric have been measured for VoIP(voice over IP) service provided through a wireless interface of WiBro(Wireless Broadband). By analyzing the measured values and correlation between the metrics, we attempt to find a method to evaluate QoE of the VoIP service in a objective way. As a result, it has been shown that QoE of the VoIP service through WiBro network has close relation to the packet-level end-to-end delay, and the delay has close relation to received signal strength indicator(RSSI).

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.6 s.324
• /
• pp.25-31
• /
• 2004

fireless LAN can offer high data rate communication between wireless terminals. In IEEE 802.11 wireless LAN, a basic service unit is called a Basic Service Set (BSS), which consists of one AP and more than one wireless terminals. Terminals far from the AP may not communicate with high data rate because signal strength is weakened as they move away from the AP. In this paper we propose a method to permit high speed data transmission by grouping terminals and by using part of wireless terminals as repeaters. We analyze the proposed and algorithm via simulations. Our proposed grouping mechanism is shown to be an effective way to increase the distance for high rate transmission.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.1223-1228
• /
• 2004

The study for ubiquitous computing infra is proceeding actively, it make possible to use service and access network anywhere, anytime because of wire/wireless communication technology and progress of hardware. Domestically, study for the network mobility support technology which is the key technology for future ubiquitous computing realization have progressed, but that is insufficient. Especially, there is no study for independent mobility support study about railway wireless network. So, this study propose network mobility management technology for mobile network infra in railway and proper network model in train.

• Proceedings of the KIEE Conference
• /
• 2005.04a
• /
• pp.241-243
• /
• 2005

The study for ubiquitous computing infra is proceeding actively, it make possible to use service and access network anywhere, anytime because of wire/wireless communication technology and progress of hardware. Domestically, study for the network mobility support technology which is the key technology for future ubiquitous computing realization have progressed, but that is insufficient. Especially, there is no study for independent mobility support study about railway wireless network. So, this study propose network mobility management technology for mobile network infra in railway and proper network model in train.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.20 no.3
• /
• pp.25-30
• /
• 2020

This study is to provide high-quality mobile communication service to subscribers and wireless communication users in a Mobile communication environment. It is about a method to secure the quality of a call by early processing a faulty radio station. The purpose of this study is to design and implement a direction detection system suitable for a mobile communication environment and portable as a method for early detection and resolution of interference and illegal wireless stations occurring in 5G mobile communication. The basic configuration of a portable direction detection system was designed, and a method was proposed to find and repair a faulty wireless station in a short time through manufacturing and experimentation.