• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.18 no.4
• /
• pp.211-218
• /
• 2018

Recently, various technologies related to IIoT are introduced continuously due to the spread of IoT and smart factory industries. This paper proposes the construction of a two-way wireless network system for monitoring plant equipment using these various technologies. The main technologies used in this thesis are design techniques for micro sensor nodes to monitor facility conditions at various sites, MQTT technology for wireless communication between local server and sensor nodes and Node-RED based design technologies, which store data collected and can be easily presented to users via wired and wireless wires. In addition, a wireless two-way camera system was also implemented in which the screen images of the site can be viewed in the situation room according to the instructions of the situation room when determining abnormal conditions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.10a
• /
• pp.851-853
• /
• 2013

Recently, location-based service as the developed continuously, interest in positioning technology is increasing. As the most famous indoor positioning technology, WPS is a positioning technology using WiFi, which can complement the limits of the indoor positioning to have a GPS. In this paper, to provide a system for monitoring the position of the inside of the user based on the position information that using the RSSI signal of the wireless AP based WPS technology, they grip the location information of the mobile nodes in the indoor. If using the method proposed, it is expected to be applied to various services it is possible to apply the WPS, this is because it is possible to estimate in real time the location distribution of mobile nodes in the indoor.

• Journal of Digital Convergence
• /
• v.15 no.7
• /
• pp.201-211
• /
• 2017

Wireless network using dynamic IP and mobile IP technology provides the user with convenience of access and movement. However, this causes the attacker who disguises normal user(pretending to be a regular user) to have more opportunity in regard to access and acquisition of information. This paper help the network administrator and the service provider quickly to recognize the attacker's intention to access network and service. Therefore network administrator and service provider can specify and respond the location of the attacker appropriately. To achieve above, we define an entity (W_L_M) that manages user information of WiFi and LTE network, and propose messages and procedures for attacker's location identification and alarm. The performance evaluation of this paper is based on qualitative analysis. By using the proposed method, some cost (message creation, processing and transmission) occurred but it was analyzed to be less than the total network operation cost. The proposal of this paper is a management method that utilizes existing network information and structure. This method can be used as a reference material to enhance security.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.32 no.6
• /
• pp.375-381
• /
• 2019

Structural health monitoring to determine structural conditions at an early stage and to efficiently manage the energy requirements of buildings using systems that collects relevant data, is under active investigation. Structural monitoring requires cutting-edge technology in which construction, sensing, and ICT technologies are combined. However, the scope of application is limited because expensive sensors and specialized technical skills are often required. In this study, a Raspberry Pi module, one of the most widely used single board computers, a Lora module that is capable of long-distance communication at low power, and a high-performance accelerometer are used to construct a wireless edge computing system that can monitor building response over an extended time period. In addition, the Raspberry Pi module utilizes an edge computing algorithm, and only meaningful data is obtained from the vast amount of acceleration data acquired in real-time. The raw data acquired using Wi-Fi communication are compared to the Laura data to evaluate the accuracy of the data obtained using the system.

• Journal of Convergence for Information Technology
• /
• v.7 no.4
• /
• pp.91-96
• /
• 2017

In this paper, we aim to respond efficiently to crime by using Arduino and smartphone apps in response to increasing number of house-breaking crimes. It receives the signal of the sensor installed in the house and connects it with the app of the smartphone. To use the app, you can download the app from the user's smartphone, launch the app, and operate the operation outside the home, not only inside the house, by linking the executed app. Among the sensors installed in the house, the movement detection sensor is used to enhance the security, and the gas leakage sensor and the flame detection sensor can be used to easily detect the risk of fire and to prevent the fire early. Security is further enhanced by the ability to remotely control the front door with a smartphone. After that, various sensors can be added and it can be developed as a WiFi module in addition to the Bluetooth module.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.6
• /
• pp.707-713
• /
• 2016

In the IEEE 802.11 Wireless LAN environment, the common Access Point (AP) selection of the existing terminal is based on signal strength. However, the signal strength-based AP selection method does not ensure an optimal data rate. Recently, several AP selection methods to solve this problem have been suggested. However, when we select AP, these have a latency problem and don't consider dense environments of AP. In this paper, we confirm the problem of the conventional AP selection about the signal strength and the throughput through the actual measurement, and propose algorithm that selects AP by scoring link speed and wireless round trip time to compensate the problem. Furthermore, the proposed AP selection algorithm through the actual experiment proves the improved performance as compared with the existing methods.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.23 no.8
• /
• pp.909-922
• /
• 2012

To fully utilize scarce spectrum resource, it's necessary to develop and evaluate promising business models prior to making technology R&D plan and industrial promotion policy. The purpose of this paper is to design potential business models, evaluate the propriety of commercializing the models, and discuss promotion policies after exploring promising sectors consuming spectrum resources. The research is based on TV white space, which is vacant TV channels in region or time domain and considered as core spectrum resource along with digital terrestrial television switchover. As the result, four kinds of business models were derived, including broadcasting and telecommunication types. Each model was discussed from four standpoints: customer value proposition, profit formula, key resources, and key processes, and the propriety for commercialization was evaluated by three dimensions: technological evaluations, business-oriented evaluations, and user-oriented evaluations. The promotion policies of government and market participants for the activation of TV White space-based business models were discussed as well.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.7B
• /
• pp.760-770
• /
• 2011

The existing mobility management schemes do not fully support the next generation network, which is composed of IP-based core network and various access networks. Currently, ETRI has been developing the AIMS (Access Independent Mobility Service) system which satisfies the ITU-T requirements of mobility management in the next generation network. The AIMS system is designed to provide a mobile host with a fast and reliable mobility service among heterogeneous access networks. Recently, many user devices have multiple communication interfaces, e.g., 3G and WLAN, and thus they can make two or more network connections at the same time. In this paper, we design a scheme of flow mobility, i.e., the movement of selected data flows from one access technology to another, to be applied in the AIMS system, and verify the proposed scheme through the NS-3 simulation study. From the simulation results, we can know that the proposed flow mobility scheme can utilize the network resource efficiently in the heterogeneous mobile networks.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.2
• /
• pp.437-444
• /
• 2014

The unmanned ship control system controls the unmanned ship at a distance in ocean. Expecially, in order to control the unmanned ship, it needs the wireless communication networks and we use the IEEE 802.11 based WLAN. The IEEE 802.11 based WLAN technology for supporting a wide bandwidth is suitable for unmanned ship control system which has to transmit the multimedia data. First, we design the system structure for controlling the unmanned ship. Then, in order to overcome the limited communication area, we design the network structure for the unmanned ship communication network which can use a various communication network. we implemented and evaluated the unmanned ship system based on WLAN. We controlled the unmanned ship by use the WLAN and confirmed the signal feature of WLAN in the ocean.

• Journal of Advanced Navigation Technology
• /
• v.22 no.4
• /
• pp.288-294
• /
• 2018

The entertainment system of the aircraft has changed its paradigm in the form of using passenger electronic devices instead of using a fixed monitor. This has simplified the on-board equipment while the risk of safety has increased with the electric charging of portable electronic devices. Unlike personal portable electronic devices that do not have a transmission function, the use of Wi-Fi enabled electronic devices(T-PED) is allowed and the battery is required to be charged in the cabin. In this study, we used the NASA Aviation Safety Reporting System to investigate the effects of changes in wireless environment and entertainment service. Based on this, we analyzed the risks of personal electronic devices by sharing event occurrence cases caused by in-flight electronic equipment or passenger portable electronic devices(especially smart phones) from the viewpoint of aircraft safety management. This analysis includes identification of potential hazards and risk assessment, and finally the strategies for risk mitigation for safe use of portable electronic devices are suggested.