• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.2
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• pp.397-408
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• 2017

As mobile traffic increases rapidly, DMM (Distributed Mobility Management) has been proposed as a mobility management technology for seamless communication of mobile devices as mobile traffic increases rapidly. the DMM distributes mobility management from the core network to the edge network, enabling stable binding updates with low latency. However, the DMM still have network delay and security problems for sessions. In this paper, we point out the problems existing in the DMM and propose a new protocol in which the MN (Mobile Node) directly participates in authentication and mutual authentication is correctly performed to solve this problem. We demonstrate not only security improvements but also performance improvements with performance analysis.

• Journal of IKEEE
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• v.24 no.3
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• pp.917-920
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• 2020

In this paper, we studied the derivation method of isoflux radiation for a planar array antenna. The presented array antenna was designed for considering of 1U-sized CubeSAT with Ku-band communications. For the presented array antenna, 8×8 radiating elements were arranged, and the distance between radiating elements was set of half-wavelength. The excited current weighting for each radiating elements was calculated by the signal processing technique used in the design of the low-pass filter. As a result of analysis of the method proposed in this paper, it was confirmed that a seamless isoflux pattern can be derived.

• The Transactions of the Korea Information Processing Society
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• v.5 no.5
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• pp.1285-1299
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• 1998

Thousands of multimedia services are being developed over existing public networks and high-speed communication networks. In the multi-carrier network, seamless integration of terminals and services is essential in order to offer an end-to-end and user-independent service. In this paper, we propose the concept of the Interworking Broker to provide an infrastructure for building multimedia service interworking platform that supports interactive multimedia applications in distributed heterogeneous network environment. We describe main techniques developed to achieve the service interworking, and also the functional architecture of the Interworking Broker in heterogeneous ATM network environments.

• Journal of Computing Science and Engineering
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• v.6 no.1
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• pp.60-66
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• 2012

It has been proved that information and communication technology (ICT) solutions for personalized health (PHealth) and ambient assisted living (AAL) can support people in their daily life activities. Several solutions have been demonstrated to empower different levels of services through seamless data acquisition and specific users' interaction modalities. Usually services usability and accessibility are handled in the design process and are validated with small users' groups. Moreover, while service design and systems development have been extensively described in literature, service deployment methodologies are not properly addressed and documented. Proper reference guidelines are also missing. The most common methodologies like unified process (UP) or ICONX can cover only the design and the development of PHealth services without a clear description on the following phases such as deployment, service provision and maintenance. These phases present several risks to be taken into account right from the beginning of the implementation of PHealth or AAL services. This paper focuses on the description of a structured methodology to deploy PHealth services and how this process can be supported by integrated software routines and adapting the UP framework in particular the "Transition phase."

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.8B
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• pp.762-770
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• 2004

With rapid advances in wireless communication technologies and with the advent of the smaller and high-performance mobile handsets nowadays, many researches are actively performed for providing seamless communications while mobile nodes are roaming around. As real-time application programs are more prevalent, it is very important to manage mobility of mobile nodes efficiently. In this paper, we propose a localized mobility support scheme that is based on the Mobile IPv6 by IETF. The proposed scheme enhances functionalities in mobile nodes and only uses signaling messages of Mobile IPv6. The performance of the proposed scheme is evaluated through analytical model and simulations. According to the results of the evaluation, the proposed scheme provides better performance than Mobile IPv6 in terms of packet losses and TCP throughput by localizing the binding update messages inside the foreign domain during handoffs and reducing binding update time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.5
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• pp.2398-2415
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• 2017

Content-Centric Networking (CCN) is a new Internet architecture with routing and caching centered on contents. Through its receiver-driven and connectionless communication model, CCN natively supports the seamless mobility of nodes and scalable content acquisition. In-network caching is one of the core technologies in CCN, and the research of efficient caching scheme becomes increasingly attractive. To address the problem of unbalanced cache load distribution in some existing caching strategies, this paper presents a neighbor cooperation based in-network caching scheme. In this scheme, the node with the highest betweenness centrality in the content delivery path is selected as the central caching node and the area of its ego network is selected as the caching area. When the caching node has no sufficient resource, part of its cached contents will be picked out and transferred to the appropriate neighbor by comprehensively considering the factors, such as available node cache, cache replacement rate and link stability between nodes. Simulation results show that our scheme can effectively enhance the utilization of cache resources and improve cache hit rate and average access cost.

• Journal of Ubiquitous Convergence Technology
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• v.2 no.1
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• pp.51-55
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• 2008

A digital home is a ubiquitous environment that is expected to be realized in the near future. All information appliances in a house are connected to each other through wired and/or wireless home networks. Authenticated user can access the various services provided by the digital home, and the access is not restricted by equipment, time, or location. The technologies that form the digital home can be grouped into two categories: wired networking technologies and wireless networking technologies. For the purpose of ubiquitous environments, wireless-networks offer suitable and seamless high-quality services. A wireless LAN can be created simply by equipping a single access point. For that reason, the cost of establishing such a network is low and using it is easy. Of course, there is an exciting new wireless technology. It is the Ultra Wide Band (UWB). However, it is not enough to bring wireless convenience, although offering a broad range of high-speed data transfer capabilities, Because of unstable. Thus, of the wireless-networking systems, we focus on the wireless LAN. We quantitatively analyze its capabilities. The dynamic and adaptive wireless LAN provides a foundation for the evolution toward the next generation of wireless and adaptive networks. The difference between wired LAN and wireless LAN in upload and download rates is small. Although the wireless LAN experiences a greater loss rate than the wired LAN, the difference is minimal. We conclude that a wireless LAN is suitable for use in an apartment environment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.2864-2870
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• 2014

We suggest various supporting methods for seamless services to support the stable service of system and network. As a representative, the redundancy is the duplication for supporting the stable service of the system and networks. The various redundancy systems have been proposed, these may have a variety forms depending on the number of the service supporting systems. We analyze a availability of a various redundancy model about a redundancy systems. We use a SRN based SPNP as an analysis tool. In this paper, we explain a various redundancy models, then compare and analyze the availability of redundancy models according to a number of service units.

• Journal of Information Technology Services
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• v.10 no.1
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• pp.177-190
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• 2011

Due to the growth of economy and the advancement of IT, the life expectancy has been prolonged and the interests in health have greatly increased. Recently the request for systems that enable measuring the bio-signals of patients in the non medical organizations, such as home, and transmitting them to medical staffs at remote sites for monitoring them. In this paper, we present an agent-based u-health system for patients or suspects with heart diseases. Our system consists of portable devices for measuring bio-signals and agents that perform data collection, data storage, automatic detection of abnormal status in patients, and HL7-based data exchange in a cooperative way. The main features of the system are : the agent-based architecture facilitates the addition of new service modules as well as the modification of existing ones; an intelligent agent is provided which automatically detects situations in which the bio-signals of patients are abnormal; the medical data standard is supported so that the communication with other systems is very easy. To our survey, there have been few previous systems which support all those features in a seamless way.

• Healthcare Informatics Research
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• v.24 no.4
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• pp.387-393
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• 2018

Objectives: This paper describes an experience of implementing seamless service trials online and offline by adopting Internet of Things (IoT) technology based on near-field communication (NFC) tags and Bluetooth low-energy (BLE) beacons. The services were provided for both patients and health professionals. Methods: The pilot services were implemented to enhance healthcare service quality, improve patient safety, and provide an effective business process to health professionals in a tertiary hospital in Seoul, Korea. The services to enhance healthcare service quality include healing tours, cancer information/education, psychological assessments, indoor navigation, and exercise volume checking. The services to improve patient safety are monitoring of high-risk inpatients and delivery of real-time health information in emergency situations. In addition, the services to provide an effective business process to health professionals include surveys and web services for patient management. Results: Considering the sustainability of the pilot services, we decided to pause navigation and patient monitoring services until the interference problem could be completely resolved because beacon signal interference significantly influences the quality of services. On the other hand, we had to continue to provide new wearable beacons to high-risk patients because of hygiene issues, so the cost increased over time and was much higher than expected. Conclusions: To make the smart connected hospital services sustainable, technical feasibility (e.g., beacon signal interference), economic feasibility (e.g., continuous provision of new necklace beacons), and organizational commitment and support (e.g., renewal of new alternative medical devices and infrastructure) are required.