• International Journal of Internet, Broadcasting and Communication
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• 제8권4호
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• pp.1-10
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• 2016

This paper considers WiMedia UWB network based wireless ship area network (WSAN) so as to support high-quality multimedia video data services and important shipboard control data. In this paper, prioritized contention access (PCA) and distributed reservation protocol (DRP) based on WiMedia UWB (ECMA-368) MAC protocols are combined and proposed to support mixed high-quality video traffic and shipboard control data traffic applying varying DRP and PCA data periods according to channel condition and link parameter ptimization. It is shown that the proposed dynmaic channel allocation of WiMedia UWB MAC protocol can provide reliable mixed video and shipboard control data traffic as well.

• 한국산학기술학회논문지
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• 제6권2호
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• pp.178-182
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• 2005

본 논문에서는 오브컴 위성 통신 및 X.400 통신 프로토콜을 이용하여 글로벌 위치 확인 시스템을 구현하는 논문으로 본 시스템은 인터넷을 통해서 전 세계 어디에서나 이동 및 고정 물체의 위치를 확인할 수 있는 양방향 데이터 통신을 제공한다. 본 연구에서는 데이터 통신 링크를 구축하기 위해서 X.400 프로토콜, 그리고 SIP(Serial Interface Protocol) 및 자체 정의한 제어 프로토콜을 사용하였다. GPS수신기와의 인터페이스를 위하여 사용자 단말기와 연결된 데이터 프로세서도 설계 및 제작하였다. 실시간 실험을 통해서 본 연구에서 제안한 글로벌 위치확인 시스템이 정해진 프로토콜에 따라서 잘 동작하는 것을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권8호
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• pp.2849-2864
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• 2021

The emerging of cloud data sharing can create great values, especially in multi-cloud environments. However, "data island" between different cloud service providers (CSPs) has drawn trust problem in data sharing, causing contradictions with the increasing sharing need of cloud data users. And how to ensure the data value for both data owner and data user before sharing, is another challenge limiting massive data sharing in the multi-cloud environments. To solve the problems above, we propose a Uniform Encoding and Parsing Framework (UEPF) with blockchain to support trustworthy and valuable data sharing. We design namespace-based unique identifier pair to support data description corresponding with data in multi-cloud, and build a blockchain-based data encoding protocol to manage the metadata with identifier pair in the blockchain ledger. To share data in multi-cloud, we build a data parsing protocol with smart contract to query and get the sharing cloud data efficiently. We also build identifier updating protocol to satisfy the dynamicity of data, and data check protocol to ensure the validity of data. Theoretical analysis and experiment results show that UEPF is pretty efficient.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권12호
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• pp.5744-5764
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• 2018

In Wireless Sensor Networks (WSNs) for Internet of Things (IoT) environment, fault tolerance is a most fundamental issue due to strict energy constraint of sensor node. In this paper, a robust energy saving data dissemination protocol for IoT-WSNs is proposed. Minimized energy consumption and dissemination delay time based on signal strength play an important role in our scheme. The representative dissemination protocol SPIN (Sensor Protocols for Information via Negotiation) overcomes overlapped data problem of the classical Flooding scheme. However, SPIN never considers distance between nodes, thus the issue of dissemination energy consumption is becoming more important problem. In order to minimize the energy consumption, the shortest path between sensors should be considered to disseminate the data through the entire IoT-WSNs. SPMS (Shortest Path Mined SPIN) scheme creates routing tables using Bellman Ford method and forwards data through a multi-hop manner to optimize power consumption and delay time. Due to these properties, it is very hard to avoid heavy traffic when routing information is updated. Additionally, a node failure of SPMS would be caused by frequently using some sensors on the shortest path, thus network lifetime might be shortened quickly. In contrast, our scheme is resilient to these failures because it employs energy aware concept. The dissemination delay time of the proposed protocol without a routing table is similar to that of shortest path-based SPMS. In addition, our protocol does not require routing table, which needs a lot of control packets, thus it prevents excessive control message generation. Finally, the proposed scheme outperforms previous schemes in terms of data transmission success ratio, therefore our protocol could be appropriate for IoT-WSNs environment.

• 조명전기설비학회논문지
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• 제25권12호
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• pp.119-131
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• 2011

To be integrated into the IEC 61970-based K-Grid, application of open communication protocol and sub-system modeling to major nodes is needed. In this paper, a module which links load nodes in customers to CIM based on psXML/oBIX, one of open protocols, was developed and data modeling and communication protocols of IEC 61850-7-42 based DER and ESS which apply the module to the customers who have DER and ESS were designed. Also the XML-based distributed database middleware was designed. The proposed modeling and protocols were applied to the building in which commercial DER products and the effectiveness of the proposed data modeling and the communication protocol were evaluated.

• 한국멀티미디어학회논문지
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• 제20권2호
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• pp.254-260
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• 2017

Data packets from sensor nodes scattered over measuring fields are generally forwarding to the sink node, which may be connected to the wired networks, in a wireless sensor network. So many data packets are gathered near the sink node, resulting in significant data packet collisions and severe transmission latency. In an event detection application such as object tracking and military, bursty data is generated when an event occurs. So many data packet should be transmitted in a limited time to the sink node. In this paper, we present a delay efficient and bursty traffic friendly MAC protocol called DEBF-MAC protocol for wireless sensor networks. The DEBF-MAC uses a slot-reserved mechanism and sleep period control method to send multiple data packets efficiently in an operational cycle time. Our simulation results show that DEBF-MAC outperforms DW-MAC and SR-MAC in terms of energy consumption and transmission delay.

• 한국산학기술학회논문지
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• 제11권9호
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• pp.3563-3570
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• 2010

무선 센서 네트워크에서 에너지 소비를 줄이기 위한 MAC 프로토콜의 연구가 진행되어 왔다. 비동기 MAC Protocol에서 Preamble의 Overhearing과 Idle listening으로 인해 불필요한 에너지가 소모 된다. 본 논문에서는 Preamble 구조에서 목적지 주소와 Preamble의 종료 시간, 전송될 데이터 길이 정보를 포함하여 Preamble Overhearing과 Data Overhearing을 감소시키고 Data의 발생 유무에 따라 Dynamic 값을 변경하여 Check Interval의 길이를 조절하는 DPL(Dynamic Preamble Length)-MAC 프로토콜을 제안하였다. 그리고 기존의 비동기 방식의 무선 센서 네트워크 MAC 프로토콜들과 본 논문에서 제안한 DPL-MAC 프로토콜을 시뮬레이션 하여 에너지 소모를 비교 분석하였다.

• 한국정보보호학회:학술대회논문집
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• 한국정보보호학회 2006년도 하계학술대회
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• pp.181-184
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• 2006

The mobile devices are constrained to be low battery, and the mobile data channel is low data rate. Therefore, the computational cost on the client side of the authentication protocol should be low. In 2005, Hwang and Su proposed an efficient authentication protocol for mobile networks. Hwang-Su protocol is more efficient than other related protocols. In this paper, we propose a new efficient authentication protocol for mobile networks. The proposed protocol is more efficient than Hwang-Su's in computational respect although our protocol is nearly equal to Hwang-Su's in communication respect. It is suitable to apply in the mobile networks.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.107-109
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• 2005

BACnet(Building Automation and Control networks) is a standard data communication protocol designed specifically for building automation and control systems. BACnet provides BACnet/IP Protocol for data communication through the internet. BACnet device transmits BACnet broadcast messages and BACnet/IP messages using conventional IP technologies. Specially, BBMD(BACnet Broadcasting Management Device) is used to deliver BACnet broadcast messages. In this study, we propose a mechanism of fault tolerant BBMD in the BACnet/IP protocol. The Fault Tolerant BBMD mechanism(FTBM) improves the connectivity of BACnet/IP networks by inheriting the operation of BBMD in the networks. The FTBM is implemented with added functions to the original BACnet/IP protocol so that it can be applied together with original BACnet/IP devices. We also prove the FTBM's backward compatibility with original BACnet/IP protocol using experimental analysis.

• 한국통신학회논문지
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• 제18권9호
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• pp.1304-1314
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• 1993

최근 몇 년 동안 이동통신의 편이성으로 인해 이동통신의 수요가 급증하고 있어 수년내에 새로운 셀룰러망으로의 진화가 절실히 요구되어지고 있다. 따라서 본 논문에서는 셀룰러망의 전화 전망에 대해서 살펴보고, 차세대 셀룰러 패켓 라디오망에서의 새로운 음성/데이타 집적 다중 엑세스 프로토콜로 가변경계 TDMA/BTMA 프로토콜을 제안하며 컴퓨터 시뮬레이션을 통해 PRMA 프로토콜과 가변경계 TDMA/BTMA프로토콜의 성능을 비교분석한다. 시뮬레이션 결과, 지연에 민감한 음성 트래픽에는 TDMA프로토콜을 사용하고, 패켓 손실에 민감한 데이타 트래픽에는 BTMA프로토콜을 사용하며, 동기신호와 제어정보 및 호 접속 계수기를 사용하여 음성과 데이타영역의 경계를 가변화시킨 가변경계 TDMA/BTMA프로토콜이 PRMA 프로토콜 보다 우수한 성능을 나타냄을 알 수 있었다.