• Journal of Advanced Technology Convergence
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• v.2 no.1
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• pp.1-7
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• 2023

Recently, there have been increasing interests in researches to apply wireless communication technologies for smart farm. This paper introduces the problems in the smart farm for the outdoor culture and technical considerations to solve the problems. As candidate technologies, this paper selects LoRa, Sigfox, NB-IoT, and Wi-Fi and then determines that LoRa is a suitable technology based on the CAPEX, coverage, transmission rate, battery, and the price. To provide technical analysis, this paper introduces technologies related to the physical and medium access control (MAC) layers as well as the security. Specifically, this paper includes the modulation technology in the physical layer, Class (Class A, B, and C) based protocol operations in MAC layer, and security architecture based on the LoRa version.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.1254-1257
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• 2017

LoRa는 저전력 및 장거리 작동을 위해 설계된 새로운 ISM 대역 무선 기술이며, LoRaWAN은 LoRa에서 정의된 광역 네트워크 프로토콜이다. 본 논문에서는 실제 환경에서 LoRaWAN 기술의 통신 성능을 검증하는 것을 목표로 한다. 이를 위해, 캠퍼스 내에 LoRaWAN 실험을 위한 실제 테스트 베드를 구축했다. 사용자들이 사용하는 실제 환경을 만들기 위해 통신 게이트웨이를 실내에 설치하였고, 캠퍼스의 실내외 다수 위치에서 데이터를 P2P 방식으로 게이트웨이에게 전송한다. 실험에서는 대역폭, 코딩 속도, 확산 계수 및 전송 전력을 변화시켰으며, 성능 검증을 위해 신호대잡음비와 패킷 전송률을 측정하여 결과를 분석한다.

• Journal of KIISE
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• v.45 no.3
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• pp.303-310
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• 2018

LoRaWAN(Long Range Wide Area Network) is a standard for low-power, long-range, low-speed communication as announced in the LoRa Alliance. LoRaWAN addresses the physical layer and medium access control layer and the technology used in the physical layer is referred to as LoRa. LoRa can be used for remote monitoring and remote control in maritime conditions. However, unlike land, marine environment is not only difficult to construct an infrastructure for service provision, but also difficult to analyze LoRa performance in maritime. In this study, we construct an infrastructure using cloud platform and analyze LoRa link performance in maritime conditions.

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

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.313-316
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• 2021

In the IoT(IoT: Internet of Things) environment, network configuration is essential to collect data generated from objects. Various communication methods are used to process data of objects, and wireless communication methods such as Bluetooth and WiFi are mainly used. In order to collect data of objects, a communication module must be installed to collect data generated from sensors or edge devices in real time. And in order to deliver data to the database, a software architecture must be configured. Data generated from objects can be stored and managed in a database in real time, and data necessary for industrial safety can be extracted and utilized for industrial safety service applications. In this paper, a network environment was constructed using a LoRa(LoRa: Long Range) gateway to collect object data, and a client/server data collection model was designed to collect object data transmitted from the LoRa module. In order to secure the resources necessary for data collection and storage management without data leakage, data collection should be possible in real time. As an application service, location data required for industrial safety can be stored and managed in a database in real time.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.3
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• pp.15-23
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• 2020

As the IoT industry expands, various application services based on location information of devices are released. In order to transmit the location information, various wireless communication technologies such as Bluetooth and Wi-Fi are used. However, these technologies have limited coverage, and cellular networks with relatively wide coverage have the disadvantage of paying for use. In this paper, we implemented our own location information system using LoRa, a low power long distance wireless communication technology. As a result, no cost is incurred and it has relatively wider coverage than other wireless communication technologies using LoRa technology. The implementation system enables LoRa communication based on IPv6 using CoAP and 6LoWPAN, and enables multiple devices to interwork with the existing Internet environment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.6
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• pp.897-906
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• 2022

In this paper, we propose a novel MAC protocol based on the harmonic transmission of ACK, called HAT-LoRa, for improving the reliability and the utilization in multiple gateway LoRa Networks. LoRa is basically vulnerable to collision due to the primitive pure ALOHA-like MAC. Whereas data frame delivery can be guaranteed by the transparent bridge of multiple receiving gateways, ACK is still transmitted by a single gateway in LoRa Network. HAT-LoRa provides the augmented reception opportunity of ACK via the simultaneous transmissions of identical ACK in multiple spreading factors. The proposed method reduces the expected transmission times of ACK double gateway environment as well as single gateway environment, by 55 and 60% in maximum, by 35% and 40% in average, in a single- and double-gateway environment, respectively. Especially, it outperforms under the environment where the distance between end device and gateways are similar to each other.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.265-266
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• 2021

In this paper, we show the case of establishing a outdoor production system using the Internet of things and define the environmental variables in the outdoor production system. By measuring soil temperature, water content, electrical conductivity and acidity through sensors, LoRa communication module transmits the information to the outdoor production system. The outdoor production system controls the amount of fertilizer and the volume of water based on this sensor data. We have developed a system that manages a wide range of crops using LoRa technology, which is a suitable communication method for cultivating crops, and manages production volume and sales performance.

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

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.100-103
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• 2019

Due to the fourth industrial revolution called 'fusion and connection', interest in 'high connectivity society' and 'highland society' is increasing, and related objects are not limited to automation and connected cars. The Internet of Things is the main concern of the 4th Industrial Revolution and it is expected to play an important role in establishing the basis of the next generation mobile communication service. Several domestic and foreign companies have been studying various types of LPWANs for the construction of the Internet based on things, and there is Semtech's LoRaWAN technology as representative. LoRaWAN is a long-distance, low-power network designed to manage a large number of devices and sensors, with communications from hundreds to thousands to thousands of devices and sensors. In this paper, we analyze the optimum node capacity of gateway for maximum performance while reducing resource waste in using LoRaWAN.