問80
頻出度★★★
IoTデバイス，IoTゲートウェイ及びIoTサーバで構成された，温度・湿度管理システムがある。IoTデバイスとその近傍に設置されたIoTゲートウェイとの間を接続するのに使用する，低消費電力の無線通信の仕様として，適切なものはどれか。
令和3年度 ITパスポート試験 問80
テクノロジ系ネットワーク › ネットワーク方式
This question's explanation and your answers so far.
解説
問 80
- ア
正解 BLE (Bluetooth Low Energy) is part of the Bluetooth standard and is a wireless communication specification specialized in linking devices over short distances with extremely low power consumption. It satisfies all three requirements in the question: “between an IoT device and an IoT gateway installed nearby”, “low power consumption”, and “wireless communication”. Because it is so power-efficient that it can run for a long time even on a button-cell battery, it is well suited for short-range connections between small IoT devices such as temperature and humidity sensors and a gateway. Therefore the correct answer is ア.
Incorrectイ
HEMS (Home Energy Management System) is a general term for systems that visualize and control the energy (such as electricity) usage within a home in order to save energy; it is not a “wireless communication specification” that connects devices. Since it is not a communication means itself, it is inappropriate.
Incorrectウ
NUI (Natural User Interface) is a user interface concept that lets people operate devices through natural actions such as voice, gestures, and touch; it has nothing to do with a wireless communication specification that connects devices.
Incorrectエ
PLC (Power Line Communication) is a “wired” communication technology that uses power lines (the wiring of electrical outlets) as the communication path. Because it is not wireless communication, it does not satisfy the question's requirement for a wireless connection, so it is inappropriate.
ここがポイント
- BLE is a wireless communication standard specialized for short-range, low-power use, suited to connecting battery-powered small IoT devices with a gateway. Remember it as a representative short-range wireless technology for an IoT area network (between devices and the gateway).
- Distinguish the confusing abbreviations: HEMS = energy management system, NUI = natural user interface, PLC = wired communication using power lines. None of them is a “low-power wireless communication specification”.
用語