• Journal of Korea Society of Digital Industry and Information Management
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• v.16 no.1
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• pp.11-19
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• 2020

IoT has been consistently used in various fields such as smart home, wearables, and healthcare. Since IoT devices are small terminals, relatively simple wireless communication protocols such as IEEE 802.15.4 and ISO 18000 series are used. In this paper, we designed the 802.15.4q 2.4 GHz TASK physical layer. Physical protocol data unit of TASK supports bit-level interleaving and shortened BCH encoding. It is spread by unique ternary sequences. There are four spreading factors to choose the data rate according to the communication channel environment. The TASK physical layer was designed using verilog-HDL and verified through the loop-back test of the transceiver. The designed TASK physical layer was implemented in a fpga and tested using MAXIM RFICs. The PER was about 0% at 10 dB SNR. It is expected to be used in small, low power IoT applications.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.3
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• pp.91-98
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• 2015

There is a new evolution in technological advancement taking place called the Internet of Things (IoT), The IoT enables physical world objects in our surrounding to be connected to the Internet. ISM (Industrial Scientific Medical) band that is 2.4GHz band authorized free of charge is being widely used for smart devices. Accordingly studies have been continuously conducted on the possibility of coexistence among nodes using ISM band. In particular, the interference of IEEE 802.11b based Wi-Fi devices using overlapping channel during communication among IEEE 802.15.4 based wireless sensor nodes suitable for low-power, low-speed communication using ISM band. Because serious network performance deterioration of wireless sensor networks. In this paper, we will propose an algorithm that identifies the possibility of using more accurate channels by mixing utilization of interference signal and RSSI (Received Signal Strength Indicator) Min/Max/Activity of Interference signal by wireless sensor nodes. In addition, it will verify our algorithm by using OPNET Network verification simulator.

• Journal of the Korea Society of Computer and Information
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• v.28 no.8
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• pp.103-109
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• 2023

In this paper, we propose a smart wall switch based on IEEE 802.11b/g/n standard 2.4GHz band communication. As the 4th industrial era evolves, smart home solution development is actively underway, and application cases for smart wall switches are increasing. Most of the Chinese products that preoccupy the market through price competitiveness use Bluetooth and Zigbee communication switches. However, while ZigBee communication is low power, communication speed is slower than Bluetooth and network configuration through a separate hub is additionally required. The Bluetooth method has problems in that the communication range and speed are lower than Wi-Fi communication, the communication standby time is relatively long, and security is weak. In this study, an IEEE 802.11b/g/n smart wall switch applied with Wi-Fi communication technology was developed. In addition, through the two-wire structure, it is designed so that no additional cost is incurred through the construction of a separate neutral line in the building. The result of the study is more than 30% cheaper than the existing wall switch, so it is judged that it will be able to preoccupy the market not only in terms of technological competitiveness but also price competitiveness.