令和4年度 ITパスポート試験問92

This question's explanation and your answers so far.

問92

頻出度★★★

IoT エリアネットワークの通信などに利用される BLE は，Bluetooth 4.0 で追加された仕様である。BLE に関する記述のうち，適切なものはどれか。

出典　令和4年度 ITパスポート試験問92

解説

問 92

Incorrectア
Incorrect. BLE is a Bluetooth-family short-range wireless standard that uses the 2.4 GHz band, and it is a different communication method from Wi-Fi (wireless LAN). A BLE device does not gain the ability to communicate directly with a Wi-Fi access point.
イ
正解 BLE stands for Bluetooth Low Energy, a power-saving specification added in Bluetooth 4.0. Thanks to its low-power design, it consumes so little power that it can run continuously for half a year to several years even on a typical button-cell battery. It is therefore well suited to uses where frequent battery replacement is difficult, such as IoT sensor devices, so choice イ correctly states BLE's greatest feature and is appropriate.
Incorrectウ
Incorrect. BLE differs from the traditional Classic Bluetooth (Bluetooth 3.0 and earlier) in both its physical layer and protocol, so the two are not compatible.
Incorrectエ
Incorrect. BLE communicates using radio waves in the 2.4 GHz band (wireless). Communication that uses infrared light belongs to other technologies such as IrDA; BLE does not use infrared.

ここがポイント

BLE (Bluetooth Low Energy) is a low-power specification added in Bluetooth 4.0; it can run continuously for half a year to several years even on a button-cell battery, and is widely used for sensor communication in IoT devices.
Keep them distinct: BLE is not compatible with traditional Classic Bluetooth, and it differs from Wi-Fi and infrared as well — it is a wireless method that uses the 2.4 GHz band.

用語

解答問92イ