• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1562-1564
• /
• 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.

• Journal of information and communication convergence engineering
• /
• v.9 no.2
• /
• pp.187-192
• /
• 2011

Traditional voice traffic over mobile communication has been changed into data and media contents traffic, which makes traffic amount increases and speedy data transfer required. In the near future ubiquitous mobile terminal environment will be common so that security issues will arise due to many heterogeneous equipments and connections. In this paper, many previous methods used for terminal authentication are examined. And we propose new system model which uses our novel user authentication protocol based on strong one-time password (OTP) and short message service (SMS). We verify our system model and protocol by implementation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.05a
• /
• pp.304-307
• /
• 2015

Virtualization lacks capabilities for enabling the application to scale efficiently because of new applications components which are raised to be configured on demand. In this paper, we propose an architecture that affords mobile app based on nomadic smartphone using not only mobile cloud computing-cloudlet architecture but also a dedicated platform that relies on using virtual private mobile networks to provide reliable connectivity through Long Term Evolution (LTE) wireless communication. The design architecture lies with how the cloudlet host discovers service and sends out the cloudlet IP and port while locating the user mobile device. We demonstrate the effectiveness of the proposed architecture by implementing an android application responsible of real time analysis by using a vehicle to applications smart phones interface approach that considers the smartphones to act as a remote users which passes driver inputs and delivers outputs from external applications.

• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.2
• /
• pp.114-119
• /
• 2010

Network technology has been developed rapidly for digital service in these days. ZigBee, one of the IEEE 802.15.4 protocols, supporting local communication has become the core technology in the wireless network area. In this paper we designed an integrated fire monitoring system using a mobile robot and the ZigBee sensor nodes which are deployed to monitor fires. When a fire breaks out, the image information of the scene of a fire is transmitted by an autonomous mobile robot and we also monitor the current position of the robot. Furthermore, the data around the place where the fire breaks out and the positions of the sensor nodes can be transmitted to a server via the multi-hop communication in the real time.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2005.05a
• /
• pp.139-143
• /
• 2005

The P2P is a network environment supporting data exchange which is directly connected peers without limit of existing server-client and intervening central server for resource or offered service with each peer. JXTA is a representative of P2P system. JXTA is a typical distributed computing model that proposed by Sun Microsystems. JXTA that doesn't require centralized services or resources is adaptable in extreme changes of network organization. MANET(Mobile Ad Hoc Network) is a representative wireless network that is composed of mobile nodes without infrastructure. So MANET establishes the path for the communication of each peers and maintains the newest routing information by exchanging routing information. In this paper, we propose a technique of JXTAMAUET which implements JXTA which is the P2P network system from the wireless network which is becoming the foundation of ubiquitous computing. For the performance evaluation of the JXTAMANET, we use simulation.

• Proceedings of the KSRS Conference
• /
• 2004.10a
• /
• pp.327-330
• /
• 2004

This research work is concerned with a location-based alert service in wireless communication network environment. The alert service automatically transfers alert message to subscriber in the disaster area. This research work deals with automatic alert services that automatically provide people in emergency area with the state of emergency. The alert service uses the mobile device to inform its urgency to the subscribers in its area. The location tracking service will give the list of people in emergency area. The all processes of this research work are followed as. First, when a disaster or a calamity comes in, an emergency management center receives the emergency to analyze its shape and size and to declare the place to 'the disaster area.' Secondly, then the center finds information of mobile device subscribers in the disaster area. Finally, the center automatically generates a shape of text or audio of alert message of the emergency to send the message to the subscribers in the disaster area. Our mobile automatic alert service proposed above is so efficient that the subscribers in disasters area may meet the emergency more efficiently and may save their own valuable lives and properties more safely.

• Proceedings of the KSRS Conference
• /
• 2004.10a
• /
• pp.276-279
• /
• 2004

The location-based service is one of the most powerful services in the mobile area. The location-based service provides information service for moving user's location information and information service using wire / wireless communication. In this paper, we propose a model for personalized recommendation system which includes location information and personalized recommendation system for location-based service. For this service system, we consider mobile clients that have a limited resource and low bandwidth. Because it is difficult to input the words at mobile device, we must deliberate it when we design the interface of system. We design and implement the personalized recommendation system for location-based services(advertisement, discount news, and event information) that support user's needs and location information. As a result, it can be used to design the other location-based service systems related to user's location information in mobile environment. In this case, we need to establish formal definition of moving objects and their temporal pattern.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.9 no.12
• /
• pp.1365-1372
• /
• 2014

In recent, the LTE(Long-Term Evolution) mobile communication system has been commercialized and a variety of service is being provided. Comparing to the old wireless access systems such as 3G mobile communications, in particular, the LTE system supports a service requiring a high transmission rate by providing broadband wireless access. In order to understand the possibility of successful support of a multimedia service such as IPTV(Internet Protocol Television) through the LTE system, it is necessary to understand the mechanism that decides the transmission rate supported by the LTE system. This paper, therefore, discusses on the relationship between a number of metrics such as CQI and BLER that affects the transmission rate with the measurement results from the field tests.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.11
• /
• pp.1457-1462
• /
• 2021

Untact order payment has become a new normal since the COVID-19. BLE beacon is a technology that supports low-power wireless communication within 70 meters without Bluetooth pairing and is specialized for indoor positioning. Therefore, it is suitable for building and providing O2O services beyond B2C and B2B services. However, beacons have a lower utilization rate because they have fewer platforms than wifi that support long-distance wireless communication. Therefore, this paper aims to provide more convenient non-face-to-face related services than before by designing and proposing an O2O service platform using BLE beacons. When scanning beacons, not only does it receive advertising data that beacons have, but it also ensures that the actual distance between the user's terminal and beacons is accurately calculated. Through accurate location, the O2O service platform will be able to provide users with store information, such as coupons and discounts, museum exhibits, and traffic information at the right time.

• Journal of KIISE:Information Networking
• /
• v.34 no.1
• /
• pp.27-32
• /
• 2007

Next-generation wireless networks are expected to support a wide range of services, including high-rate data applications, Various service types request differentiated QoSs(Qualities of Service) such as minimum data rate, accuracy, fairness and so on. Although resources of radio systems are limited, for many applications, it is important that certain QoS targets are required to be met. In this paper, we propose a QoS based scheduling algorithm for next generation systems, based on analyzing previous researches, and we develop the proposed QoS algorithm only for MIMO(multi-Input Multi-Output) systems. Moreover, we subsequently prove that the proposed algorithm optimize throughput relative to prespecified target values and converge to certain throughput.