• Journal of Advanced Navigation Technology
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• v.23 no.1
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• pp.90-96
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• 2019

LPWA is a cost-effective and time-saving technology with wide coverage. However, the LPWA is an ISM band that uses UHF radio waves, and its performance is very poor indoors because of its strong linearity. But, because of the possibility of achieving high performance compared to other communication in the room, this paper has studied the indoor communication performance by applying LoRa in LPWA technologies. After installing the data receiving module on the 4th floor, the transmission module was placed at the end of the building from the same floor to the 1st floor, and the data was collected. As a results, it installed on the 1st floor can be collected data with 98 ~ 99% probability, and the lowest RSSI is about -116dBm. Thus, considering the specification of LoRa with a maximum reception sensitivity -136dBm when the spreading factor is 12, the application of LPWA in the industrial field can be fully considered.

• Electronics and Telecommunications Trends
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• v.32 no.1
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• pp.46-53
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• 2017

넓은 커버리지를 요구하는 응용이 늘면서 서비스 지연에 민감하지 않은 소량의 데이터를 전달하기에 적합한 LPWA 네트워크 기술이 주목받고 있다. 본고는 LPWA 네트워크기술을 시장과 밀접한 관련을 갖고있는 무선 대역으로 구분하여, 비면허 대역 기술과 면허 대역 기술로 나누어 최근 개발 및 확산 동향을 살펴본다. 특히, 비면허 대역의 대표적인 기술인 Sigfox, LoRaWAN, PRMA 등의 기술을 다루었으며, 면허 대역의 기술로는 3GPP의 LTE기술을 중심으로 살펴본다. 또한, LPWA네트워크 기술과 관련하여 최근 진행 중인 IETF의 표준화 동향을 정리한다.

• Journal of Advanced Navigation Technology
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• v.22 no.1
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• pp.37-42
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• 2018

Recently, there have been many studies on the IoT environment in which the sensors attached to the equipment automatically transmit and process the site information in real time through the network to control the equipment. The core of such a system is a network for data transmission and reception, and a wired network with wide transmission distance is a priority. However, in the case of a wired network, there is a problem that the time and cost consumed to configure the communication is higher than that of the wireless. In this paper, we propose LPWA - based wireless data transmission system using LPWA and BLE communication to solve this problem. The proposed system collects data from equipment through BLE and transmits data to the server using LPWA. Experimental results show that the spreading factor of maximum length of LPWA is 8, and the minimum length is 9.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.591-593
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• 2019

LPWA has a small amount of data that can be transmitted at one time, but it can collect a very wide range of information, so it is suitable for gathering information of apartment meter or collecting data intermittently sent from industrial site. However, most of the application studies on LPWA are limited to outdoor, especially LOS environment, so it is difficult to collect information for application to apartment and industrial sites. In this paper, we have measured the communication coverage within the building, which is a NLOS environment, so that LPWA communication can be applied to apartments and industrial sites. For the experiment, LoRa module was created using sx1276, Class A was applied, and the spread factor was changed for each layer. As a result, in case of spreading factor 7 that shows increasing error and losses from the 7 floor, but the in case of spreading factor 12, the data could be seamlessly received even on the 9th floor without error and losses.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.309-311
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• 2017

With the recent development of the Internet (IoT) technology, we have come to a very connected society. This paper focuses on the security aspects that can occur within the LPWA Network environment of the Internet of things, and proposes a new machine learning method considering next generation IPS / IDS that can detect and block unexpected and unusual behavior of devices.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.2
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• pp.283-288
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• 2019

LPWA (Low Power Wide Area) networks have been considered as one of the technologies which can be implemented in IoT (Internet of Things) applications by providing less power and longer communication range compared with existing wireless technologies. In this paper, we investigate LoRa which is one of representative technologies for LPWA networks. First, we present general properties and several technologies of LPWA networks. Then, the technical specification, properties, and pros/cons of LoRa are studied. Finally, we discuss analysis of LoRa's performance and its ehancement technologies by focusing on physical layer and MAC (Medium Access Control) layer.

• Journal of Internet of Things and Convergence
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• v.2 no.3
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• pp.31-35
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• 2016

IoT technologies have been rapidly developed in recent years, and applied to many industries. In the field of fisheries, the water quality management system have been developed, helping in improving productivity and working environment. In this paper, we have designed the smart feeding system, interoperable with the water quality system, using LPWA network. LPWA network is an IoT network, which is appropriate to fish farms because of its wide area coverages and low power consumption. We expect this work to contribute to developing the aquaculture technology through the big data analysis with the accumulated data.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.569-570
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• 2018

Recently, Although particulate matter monitoring has been attracting attention as a result of social attention to the human impact of particulate matter, data suitable for the residential environment can not be obtained due to imbalances in the installation of monitoring stations and differences in topography. In this paper, we propose LoRa LPWA-based particulate matter measurement system which can make long distance wireless communication to measure particulate matter in residential environment. In the proposed system, it is possible to collect the data of the external environment which is difficult to construct the internet by utilizing LPWA which is a long distance wireless communication technology. When the proposed system is applied to the residential environment, it is expected to provide particulate matter monitoring information suitable for the residential environment.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.4
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• pp.695-702
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• 2020

Recently, as research on smart farms has been actively conducted, indoor environment control, such as a green house, has reached a high level. However, In the field of forestry where cultivation is carried out in outdoor, the use of ICT is still insufficient. In this paper, we propose LPWA-based forest growth environment collection and big data analysis system using ICT technology. The proposed system collects and transmits the field cultivation environment data to the server using small solar power generation and LPWA technology based on the oneM2M architecture. The transmitted data is constructed as big data on the server and utilizes it to predict the production and quality of forest products. The proposed system is expected to contribute to the production of low-cost, high-quality crops through the fusion of renewable energy and smart farms. In addition, it can be applied to other industrial fields that utilize the oneM2M architecture and monitoring the growth environment of agricultural crops in the field.

• Journal of Internet of Things and Convergence
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• v.8 no.4
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• pp.17-23
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• 2022

NB-IoT and LTE Cat.M1 based on LPWA(Low Power Wide Area) are commercialized and serviced by mobile carriers. As the demand for IoT devices is increased, the number of subscribers to these services is also increasing. In the beginning of service, there was no issue that eNB capacity for NB-IoT and LTE Cat.M1. However, as the number of subscribers increases, there is an issue that the eNB capacity for these service is insufficient. Active UE capacity issue may cause overload by continuous increase and temporary increase. In this paper, we propose a solution to solve the problem of LTE RRC(Radio Resource Control) Active UE capacity shortage and base station overload caused by the increase of NB-IoT and LTE Cat.M1 UE in same eNB. The proposed solution can increase a cell capacity without cell division and additional eNB, and can also improve the service quality of these UEs.