• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.42 no.3
• /
• pp.677-685
• /
• 2017

Supply rate is very low because conventional smart system of streetlight management requires a lot of time and cost until now. In this paper, we demonstrated maintaining system for streetlight which uses LoRaWAN to solve following those reasons. Using LoRaWAN is subject to build long range and low power communication. Furthermore, it helps to make low initial and cost for maintenance. Detecting problem of streetlight in real time and controling streetlight based on situation and environment are additional benefits. This system on control part is carried by administrator in GUI environment. Finally, we verified the proposed system of performance for LoRaWAN communication and sensor accuracy.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.5
• /
• pp.1540-1560
• /
• 2022

Latest technological innovation in the development of compact lower power radios has led to the explosion of Internet of Things. With Wi-Fi, Zigbee and other physical layer protocols offering short coverage area there was a need for a RF protocol that had a larger coverage area with low power consumption. LoRa offers Long Range with lower power consumption. LoRa offers point to point and point to multipoint connections. with Single hop communication in place the need for routing protocols are eliminated. LoRa Wide Area Network stack can accommodate thousands of nodes under a single LoRa gateway with a single hop communication between the end nodes and LoRaWAN gateway. This paper takes an experimental approach to analyze the basic physical layer parameters of LoRa and the practical coverage offered by a LoRaWAN under highly dense urban conditions with variable topography. The insights gained from the practical deployment of the LoRaWAN network, and the subsequent performance analysis is used to design a novel public utility monitoring platform. The second half of the papers is designing a robust platform to integrate both existing wired sensor water meters, current and future generation wireless water meters. The Common Automated Metering Platform is designed to integrate both wired sensors and wireless (LoRaWAN and Wi-Fi) supported water meters. This integrated platform reduces the number of nodes under each LoRaWAN gateway and thus improves the scalability of the network. This architecture is currently designed to accommodate one utility application but can be modified to integrate multi-utility applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2001.10a
• /
• pp.499-502
• /
• 2001

FreeS/WAN[l] 은 LINUX 상에서 네트워크 보안 프로토콜표준인 IPSEC을 구현한 공개 S/W이다. 현재 LINUX Project로 수행되고 있으며 1.91 version 까지 나와 있다. 라우터와 라우터간에 IPSEC을 사용하여 통신함으로써 access control, connectionless integrity, data origin authentication, protection against replays, confidentiality의 서비스를 보장받을 수 있고, 또한 이러한 서비스들은 IP 계층에서 제공되기 때문에 IP 계층뿐만 아니라 그 이상의 계층에 대한 보호를 제공한다. [2] 본 논문에서는 LINUX router에 FreeS/WAN IPSEC을 설치하여 Security Gateway를 구성하고, 이 Security Gateway를 통해 전형적인 가상사설망을 구성할 수 있음을 보였다. 양단의 Security Gateway에 설치되어진 FreeS/WAN으로 VPN connection을 설정하고, 인증방법으로 RSA authentication key를 setup 하였다. IPSEC을 통하여 암호화되어진 데이터로 양단의 Gateway 구간에서 보안통신이 이루어짐을 알아본다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2019.10a
• /
• pp.153-155
• /
• 2019

국방무기체계 분야 중 단일 센터에 대규모 분산시스템을 구성하는 경우 신속한 데이터 처리를 위해 통신 미들웨어로 사용되는 DDS의 패킷을 튜닝하여 사용하고 있다. 하지만 향후 국방무기체계는 생존성 보장을 위해 분산시스템의 장소를 주/예비 센터로 이원화하면서 센터간에도 신속한 데이터 동기화 및 비상시 OO초 내 센터 임무전환까지 함께 요구하고 있다. 따라서 단일 센터에서 적용한 DDS 패킷 전송 방식을 WAN 환경에 적용 시 데이터 송수신간 패킷의 순서가 바뀌는 현상이 발생하여 데이터 공유가 제한될 수 있다. 본 연구에서는 이와같은 제한사항을 극복하기 위해 DDS를 적용한 LAN 구간의 기존 성능을 유지하면서 WAN 구간 데이터의 신뢰성 보장을 위한 TCP/IP 기반의 WAN Sync 설계를 제시하였다.

• Smart Media Journal
• /
• v.13 no.1
• /
• pp.45-51
• /
• 2024

Long Range Wide Area Network (LoRaWAN) is a widely adopted Internet of Things (IoT) protocol due to its high range and lower energy consumption. LoRaWAN utilizes Adaptive Data Rate (ADR) for efficient resource (e.g., spreading factor and transmission power) management. The ADR manages these two resource parameters on the network server side and end device side. This paper focuses on analyzing the ADR and Gaussian ADR performance of LoRaWAN. We have performed NS3 simulation under a static scenario by varying the antenna height. The simulation results showed that antenna height has a significant impact on the packet delivery ratio. Higher antenna height (e.g., 50 m) has shown an improved packet success ratio when compared with lower antenna height (e.g., 10 m) in static and mobility scenarios. Based on the results, it is suggested to use the antenna at higher allevation for successful packet delivery.

• Journal of Korea Multimedia Society
• /
• v.23 no.2
• /
• pp.282-292
• /
• 2020

In order to minimize casualties from marine vessel accidents that occur frequently at home and abroad, it is important to ensure the safety of the passengers aboard the vessel in the event of an accident. There is an EPIRB system as a system for disaster preparedness in the marine situation currently on the market, but there is a problem that the price is very expensive. In order to overcome the cost problem, which is a disadvantage of previous system, LoRaWAN-based communication is used. LoRaWAN communication-based vessel positioning and risk detection system based on LoRaWAN communication transmits measurement data of each module using two Beacon and GPS modules to stably perform position measurement for both indoor and outdoor situations. The rider danger situation detection system can detect the safety status of the rider using the 3-axis acceleration sensor, collect data from the rider positioning system and the rider safety status detection system, and send to server using LoRa communication. When conducting communication experiments in the long-distance maritime situation and actual communication experiments using the implemented system, it was found that the two experiments showed over 90% communication success rate on average.

• Journal of Acupuncture Research
• /
• v.15 no.2
• /
• pp.61-79
• /
• 1998

In order to study the immunohistochemical effects of herbal drug-acupuncture of Radix paeoniae lactiflorae on gastric ulcer induced by HCl-aspirin in rats. this experiment was done by herbal drug-acupuncture to Wisu($B_{21}$). Chung-Wan($CV_{12}$), Chok-Samni($S_{36}$) loci to measure histological features of ulcer lesion, the change of numbers of parietal cell, chief celI, gastrin and somatostatin-immunoreactive cell. The obtained results were as follows; 1. The ulcerative lesions of gastric mucosa were decreased to WiSU($B_{21}$) loci followed by Chung-Wan($CV_{12}$) and Chok-Samni($S_{36}$) loci compared to the control groups. 2. In the numbers of parietal cell, the most remarkable decrease was observed to Wisu($B_{21}$) loci followed by Chung-Wan($CV_{12}$) and Chok-Samni($S_{36}$) loci compared to the control groups. 3. In the numbers of chief cell, the most remarkable increase was observed to Wisu($B_{21}$) loci followed by Chung-Wan($CV_{12}$) and Chok-Samni($S_{36}$) loci compared to the control groups. 4. In the numbers of gastrin-immunoreactive cell, the most remarkable decrease was observed to Wiu($B_{21}$) loci followed by Chung-Wan($CV_{12}$) and Chok-Samni($S_{36}$) loci compared to the control groups. 5. In the numbers of somatostatin-immunoreactive cell, the most remarkable decrease was observed to Wisu($B_{21}$) loci followed by Chung-Wan($CV_{12}$) and Chok-Samni($S_{36}$) loci compared to the control groups.

• Journal of KIISE
• /
• v.44 no.7
• /
• pp.733-741
• /
• 2017

LPWAN(Low Power Wide Area Network) technology is M2M (Machine to Machine) networking technology for the Internet of Things. The technology is designed to support low-power, long-distance and low-speed communications that are typical of LoRaWAN(Long Range Wide Area Network). To exchange inter-object information using a LoRaWAN, the link performances for various environments must be known. however, active performance analysis research that is based on an empirical environment is nonexistent. Therefore, this paper empirically evaluates the performance of the LoRa (Long Range) link, a physical communication technology of the LoRaWAN for various variables that may affect the link quality in indoor and outdoor environments. To achieve this, a physical performance monitoring system was designed and implemented. A communication experiment environment was subsequently constructed based on the indoor and outdoor conditions. The SNR(Signal to Noise Ratio), RSSI(Received Signal Strength Indication), and the PDR(Packet Delivery Ratio) were evaluated.

• Journal of the Korea Society of Computer and Information
• /
• v.29 no.1
• /
• pp.1-9
• /
• 2024

This paper proposes an integration of the ED-H scheduling algorithm, known for optimal real-time scheduling, with the LoRaEnergySim simulator. This integration facilitates the simulation of interactions between real-time scheduling algorithms for tasks with time constraints in Class-A LoRaWAN Class-A devices using a super-capacitor-based energy harvesting system. The time and energy characteristics of LoRaWAN status and state transitions are extracted in a log format, and the task model is structured to suit the time-slot-based ED-H scheduling algorithm. The algorithm is extended to perform tasks while satisfying time constraints based on CPU executions. To evaluate the proposed approach, the ED-H scheduling algorithm is executed on a set of tasks with varying time and energy characteristics and CPU occupancy rates ranging from 10% to 90%, under the same conditions as the LoRaEnergySim simulation results for packet transmission and reception. The experimental results confirmed the applicability of co-simulation by demonstrating that tasks are prioritized based on urgency without depleting the supercapacitor's energy to satisfy time constraints, depending on the scheduling algorithm.

• Proceedings of the Korea Technology Innovation Society Conference
• /
• 2006.11b
• /
• pp.301-313
• /
• 2006