• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.139-140
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• 2009

양성자 기반 공학 기술 개발 사업단은 20MeV 양성자 가속기를 운전 중이며, 진공, 빔 계측, 전원 등의 장치에 대한 제어 시스템을 개발 운영 중이다. 대형 입자 가속기를 위한 제어 시스템의 전체 네트워크는 사용자 인터페이스와 제어계가 단일 네트워크를 공유하고 있으며 EPICS(Experimental Physics and Industrial Control System) CA(Channel Access)통신을 이용하여 데이터를 상호 교환한다. 그러나 단일 네트워크를 사용함으로서 관리자만이 제어해야 할 데이터는 많은 클라이언트에게 노출되는 문제점이 있다. 그러므로 클라이언트의 접근을 제어하여 제어계로부터 전달되는 신호들의 안정성과 보안성을 유지할 수 있는 방법이 요구된다. 본 논문에서는 제어시스템에 보안성과 안정성을 유지하기 위하여 클라이언트를 Control Network, 제어계를 Machine Network로 분산시키고 통신 중계기 역할을 하는 CA Gateway를 적용하여 클라이언트에게 접근 권한을 주는 기법을 제시하고 구현 및 그 결과를 보고한다.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.613-619
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• 2020

Hybrid media access control (MAC) is used in internet of things (IoT) network, because of communication feature concern with data capacity and communication interval between gateway and sensor nodes and the cost efficiency. Hybrid MAC consists of TDMA and CSMA generally. The distance between gateway and sensor node is openly changed in marine IoT network. Therefore, it is needed to control the period of timeslot of hybrid MAC used in marine IoT network. In this paper, the design rule of TDMA timeslot with the variable period depending on communication distance was proposed. It was confirmed from the analysis that 72 times communication between gateway and sensor nodes is possible in LoRa network by using the proposed TDMA variable timeslot scheme.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.6 s.336
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• pp.9-16
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• 2005

In this paper, we focus on supporting the convergence of broadcasting and communication in home network systems with E-PON based home gateway. We propose a new architecture to provide broadcasting and data services in integrated home network using overlay transport mechanism in access network and If multicast techniques of IGMP and IGMP snooping in home network. We also detail a set of mechanisms and procedures for home broadcasting service through the home gateway system. Our new scheme is composed of three parts: a) an overlay transmission model of video broadcasting signals (satellite and/or cable TV) and Internet data, b) to select a specific video broadcasting channel and to make of the selected video broadcasting stream into IP multicast packets in tuner/conversion module using multiple tuner system and c) to transfer the converted If multicast packets to L2 switch of home gateway's core module and to send them out to target port(s) by L2 multicast using IGMP snooping.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.1
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• pp.24-51
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• 2011

When supporting both voice and TCP in a wireless multihop network, there are two conflicting goals: to protect the VoIP traffic, and to completely utilize the remaining capacity for TCP. We investigate the interaction between these two popular categories of traffic and find that conventional solution approaches, such as enhanced TCP variants, priority queues, bandwidth limitation, and traffic shaping do not always achieve the goals. TCP and VoIP traffic do not easily coexist because of TCP aggressiveness and data burstiness, and the (self-) interference nature of multihop traffic. We found that enhanced TCP variants fail to coexist with VoIP in the wireless multihop scenarios. Surprisingly, even priority schemes, including those built into the MAC such as RTS/CTS or 802.11e generally cannot protect voice, as they do not account for the interference outside communication range. We present VAGP (Voice Adaptive Gateway Pacer) - an adaptive bandwidth control algorithm at the access gateway that dynamically paces wired-to-wireless TCP data flows based on VoIP traffic status. VAGP continuously monitors the quality of VoIP flows at the gateway and controls the bandwidth used by TCP flows before entering the wireless multihop. To also maintain utilization and TCP performance, VAGP employs TCP specific mechanisms that suppress certain retransmissions across the wireless multihop. Compared to previous proposals for improving TCP over wireless multihop, we show that VAGP retains the end-to-end semantics of TCP, does not require modifications of endpoints, and works in a variety of conditions: different TCP variants, multiple flows, and internet delays, different patterns of interference, different multihop topologies, and different traffic patterns.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.1
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• pp.131-139
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• 2012

The cloud storage has the client lend and use the device as a form of service rather than owning it, and thus the client pays the charge for the service that he or she actually uses, making it beneficial over the self-managed data center. When the storage service is provided on public cloud, however, the clients does not have any control over the user data, which brings a problem of violating data confidentiality. In this paper, we propose a gateway that works between the public cloud and the client for the purpose of guaranteeing the confidentiality of user data stored in cloud. The gateway encrypts or decrypts, and then delivers the user data without the client's intervention. In addition, it provides the function of exchanging keys to allow the client to access through another gateway. The proposed idea has been tested on a commercial public cloud and verified to satisfy security and compatibility.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.7 no.2
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• pp.127-131
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• 2007

The control of electrical appliances residing in the home network can be accomplished via Internet with the UPnP expansion without modifying an existing UPnP. In this paper, we propose the Internet Gateway that consists of an UPnP IGD(Internet Gateway Device) DCP(Device Control Protocol) and an UPnP Bridge as a system to control electrical appliances of home network. UPnP IGD DCP is to enable the configurable initiation and sharing of Internet connections as well as assuring advanced connection-management features and management of host configuration service. It also supports transparent Internet access by non-UPnP-certified devices. UPnP Bridge searches for local home network devices by sending control messages, while control point of UPnP Bridge looks up devices of interest on the Internet, subsequently furnishing the inter-networking controlling among devices which belong to different home network systems. With our approach, devices on one home network can control home electrical appliances on the other home network via Internet through IGD DCP with control commands of UPnP.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.1
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• pp.51-58
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• 2015

Internet of Thing is a collection of various technical components, and the interworking among heterogeneous devices, networks, applications is expected to be accelerated through the openness of IoT platform. For this reason, many technical and administrative security threats will occur in IoT environments. In this paper, authentication methods of recent researches are analyzed for safe IoT services, and new mutual authentication protocol is proposed to provide more secure communication. The proposed protocol prevents an impersonation as malicious gateway or illegal device providing mutual authentication between gateway and IoT device. The performance analysis and evaluation of proposed authentication protocol are performed.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.637-639
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• 2002

현재 인터넷은 저렴한 사용료와 정보에 대한 욕구를 충족시키는 방대한 공개 자료를 바탕으로 그 규모를 더욱 확대하여 가고 있으며, 이러한 인터넷 사용자의 확대는 새로운 서비스에 대한 요구를 창출하게 되었다. 이러한 저렴하고 규모가 큰 인터넷을 이용하여 기존의 통신망을 대체하는 연구가 활발히 이루어지고 있으며, VoIP(Voice over Internet Protocol)가 인터넷의 대표적인 서비스로 등장하고 있다. VoIP 서비스에 대한 연구는 IETF와 ITU가 중심이 되어 이루어지고 있으며 IETF에서 제안한 MGCP, SIP 와 ITU에서 제안한 H.323 과 같은 프로토콜을 기반으로 VoIP 서비스를 위한 다각적인 접근과 연구가 진행중이다. 본 연구는 VoIP 서비스를 위한 여러 프로토콜 중 IETF가 주관하고 있는 MGCP(Media Gateway Control Protocol ) 스팩에 따라 MGCP를 이용한 ADSL-VoIP Gateway를 개발하여 보다 효율적인 망 자원 활용을 가능하게 하며, 향후 제공될 다양한 음성／동영상 서비스에 대한 기반을 마련하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.341-344
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• 2000

Recently, there have been many systems, which are not only for the access to the Internet but also for information search. To offer information, using Common Gateway Interface has been popularized as a system structure. However, the service has many problems. To solve these problems, this study is to structure the information system using middleware and to describe the embodied scheme. This study is to give embodied scheme and database, which can give information about the ocean and the Fisheries products on the formed web.

• Journal of Communications and Networks
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• v.7 no.3
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• pp.284-293
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• 2005

A critical issue in applications involving networks of wireless sensors is their ability to synchronize, and mitigate the fading propagation channel effects. Especially when distributed 'slave' sensors (nodes) reach-back to communicate with the 'master' sensor (gateway), low power cooperative schemes are well motivated. Viewing each node as an antenna element in a multi-input multi-output (MIMO) multi-antenna system, we design pilot patterns to estimate the multiple carrier frequency offsets (CFO), and the multiple channels corresponding to each node-gateway link. Our novel pilot scheme consists of non-zero pilot symbols along with zeros, which separate nodes in a time division multiple access (TDMA) fashion, and lead to low complexity schemes because CFO and channel estimators per node are decoupled. The resulting training algorithm is not only suitable for wireless sensor networks, but also for synchronization and channel estimation of single- and multi-carrier MIMO systems. We investigate the performance of our estimators analytically, and with simulations.