• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.48-48
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• 2000

We developed a wireless communication system for multiple instrumentation system. The developed system has a function of remote instrumentation and PLC(Programmable Logic Controller) control. The system consists of CC(Control and Communication) protocol, wireless media access and physical media system. For multiple wireless communication, we propose a hub polling protocol based on master-slave control concept. To show the validity of the developed system, several experiments are illustrated.

• International Journal of Internet, Broadcasting and Communication
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• 제13권3호
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• pp.25-33
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• 2021

Energy-harvesting wireless sensor networks(EH-WSNs) can collect energy from the environment and overcome the technical limitations of existing power. Since the transmission distance in a wireless sensor network is limited, the data are delivered to the destination node through multi-hop routing. In EH-WSNs, the routing protocol should consider the power situations of nodes, which is determined by the remaining power and energy-harvesting rate. In addition, in applications such as environmental monitoring, when there are urgent data, the routing protocol should be able to transmit it stably and quickly. This paper proposes an adaptive routing protocol that satisfies different requirements of normal and urgent data. To extend network lifetime, the proposed routing protocol reduces power imbalance for normal data and also minimizes transmission latency by controlling the transmission power for urgent data. Simulation results show that the proposed adaptive routing can improve network lifetime by mitigating the power imbalance and greatly reduce the transmission delay of urgent data.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.117-119
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• 2006

BACnet(Building Automation and Control networks) is a standard data communication protocol designed specifically for building automation and control systems. BACnet provides five options for datalink layer protocols and these five datalink layer options can be applied with various transmission media. Recently wireless technology prevails in automation area. ZigBee is a standard protocol based on IEEE 802.15.4 for low-speed wireless communication network. In this study, we propose a BACnet/ZigBee model that uses ZigBee wireless technology in a BACnet communication network system as a wireless datalink layer protocol. We also applied this model to a lighting control system to evaluate the feasibility of proposed technology. The technology proposed in this paper can extend the application of BACnet not only for building automation but also for home automation by taking the advantages of ZigBee wireless communication technology in BACnet communication network systems.

• ETRI Journal
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• 제31권1호
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• pp.83-85
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• 2009

Compared with unicast, multicast over wireless ad-hoc networks do not support reliability due to their inability to exchange request-to-send/clear-to-send (RTS/CTS) and ACK packets with multiple recipients. Although several media access control (MAC) layer protocols have been proposed to provide reliable multicast, these introduce additional overhead, which degrades system performance. A novel MAC protocol for reliable wireless multicast is proposed in this paper. By adapting orthogonal frequency division multiple access characteristics in CTS and ACK packets, the protocol achieves reliability over wireless multicast with minimized overhead.

• International Journal of Internet, Broadcasting and Communication
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• 제7권1호
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• pp.30-35
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• 2015

The most important factor within the wireless sensor network is to have effective network usage and increase the lifetime of the individual nodes in order to operate the wireless network more efficiently. Therefore, many routing protocols have been developed. The LEACH protocol presented by Wendi Hein Zelman, especially well known as a simple and efficient clustering based routing protocol. However, because LEACH protocol in an irregular network is the total data throughput efficiency dropped, the stability of the cluster is declined. Therefore, to increase the stability of the cluster head, in this paper, it proposes a stochastic cluster head selection method for improving the LEACH protocol. To this end, it proposes a SH-LEACH (Stochastic Cluster Head Selection Method-LEACH) that it is combined to the HEED and LEACH protocol and the proposed algorithm is verified through the simulation.

• 한국정보통신학회논문지
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• 제16권3호
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• pp.460-469
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• 2012

본 논문에서는 UWB 기술 기반 WiMedia Distributed Medium Access Control (D-MAC) 표준 프로토콜에 적용할 수 있는 협력 통신 프로토콜을 제안한다. 이를 위해 무선 채널 상태에 따라 변화하는 UWB 링크 전송 속도에 적응적인 릴레이 노드 선정 알고리즘을 제안한다. 본 논문에서 제안하는 UWB 링크에 적응적인 릴레이 통신 프로토콜은 분산적인 D-MAC 표준 기술 및 무선 USB 기술과 호환성을 갖고, 각 디바이스에서 독립적으로 실행되는 Relay Node Selection (RNS) 기준에 따라 실행된다.

• Journal of information and communication convergence engineering
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• 제5권3호
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• pp.194-199
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• 2007

In this paper, a slotted CDMA_ALOHA protocol with hybrid ARQ is proposed for the wireless CDMA communication networks. The proposed protocol combines the characteristics of the slotted ALOHA, CDMA, and the hybrid ARQ, in order to increase the throughput by reducing the number of retransmissions when the channel experiences heavy traffic. The main feature of the proposed protocol is the utilization of the forward error correction capability to correct errors that appear after the CDMA dispreading of the packets. The base station does not need to ask so often for retransmission of erroneous packets. It will request for retransmission only when the FEC capability is exceeded. The performance of the proposed protocol is analyzed by considering the packet collision probability as well as the bit error probability. The numerical results show that the system throughput is closely related to the bit error rate of the wireless link and the FEC coding rate.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 춘계종합학술대회
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• pp.435-438
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• 2003

본 연구 논문에서는 기존의 무선통신을 이용한 정보전송의 단점인 통신비의 계속적 지출을 보완하고 MS카드의 정보를 무선으로 전송을 할 수 있는 시스템을 구현하였다. 테마파크나 주유소등 소규모의 네트워크로 충분히 소화가 가능한 지역의 경우 그 보안성이 우수하며 통신비용이 추가적으로 들지 않는 블루투스 프로토콜을 이용하여 효율적인 매장 관리를 가능케 하는 역할이 가능하다. 기존의 무선통신의 경우 지역적 통신망 내에서의 통신에도 추가적인 통신비용이 필요로 하는 무선 랜 프로토콜을 기반으로 네트워크를 구성하거나 보안이 취약한 RF 프로토콜을 이용한 네트워크를 구성하고 있다. 본 논문에서는 추가적인 비용이 전혀 들지 않는 지역적 통신망에 적합하면서도 주파수 호핑 방식으로 인한 보안성이 매우 좋은 블루투스 프로토콜을 통해 정보를 전송할 수 있도록 설계 하였다. 단말기는 저 전력, 고 성능의 RISC프로세서와 큰 화면의 LCD를 제공함으로써 점원용 휴대용 기기에 적합하도록 설계하였다. 본 논문에서 구현한 블루투스를 이용한 마그네틱 카드 정보 전송 시스템은 기존의 매장관리용 무선통신 시스템을 대체하여 추가적인 통신비용이 없이 지역적 통신망을 구축하고, 정보전송의 보안성을 높이며, 단말기의 저 전력 설계로 보다 오랜 시간 효율적으로 매장을 관리 할 수 있을 것이다.

• Journal of information and communication convergence engineering
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• 제8권2호
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• pp.212-218
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• 2010

In wireless sensor networks (WSNs), both efficient energy management and Quality of Service (QoS) are important issues for some applications. For creating robust networks, real-time services are usually employed to satisfy the QoS requirements. In this paper, we proposed a hierarchical real-time MAC (medium access control) protocol for (m,k)-firm constraint in wireless sensor networks shortly called HRTS-MAC. The proposed HRTS-MAC protocol is based on a dynamic priority assignment by (m,k)-firm constraint. In a tree structure topology, the scheduling algorithm assigns uniform transmitting opportunities to each node. The paper also provides experimental results and comparison of the proposed protocol with E_DBP scheduling algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권10호
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• pp.5035-5057
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• 2019

Advancements in nanotechnology and novel nano materials in the past decade have provided a set of tools that can be used to design and manufacture integrated nano devices, which are capable of performing sensing, computing, data storing and actuation. In this paper, we have proposed cooperative nano communication using Power Switching Relay (PSR) Wireless Power Transfer (WPT) protocol and Time Switching Relay (TSR) WPT protocol over independent identically distributed (i.i.d.) Rayleigh fading channels in the Terahertz (THz) Gap frequency band to increase the range of transmission. Outage Probability (OP) performances for the proposed cooperative nano communication networks have been evaluated for the following scenarios: A) A single decode-and-forward (DF) relay for PSR protocol and TSR protocol, B) DF multi-relay network with best relay selection (BRS) for PSR protocol and TSR protocol, and C) DF multi-relay network with multiple DF hops with BRS for PSR protocol and TSR protocol. The results have shown that the transmission distance can be improved significantly by employing DF relays with WPT. They have also shown that by increasing the number of hops in a relay the OP performance is only marginally degraded. The analytical results have been verified by Monte-Carlo simulations.