問86
頻出度★★★
IoT 端末で用いられている LPWA (Low Power Wide Area) の特徴に関する次の記述中の a, b に入れる字句の適切な組合せはどれか。 LPWA の技術を使った無線通信は, 無線 LAN と比べると, 通信速度は [ a ]，消費電力は [ b ]。
平成31年度 春期 ITパスポート試験 問86
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 86
Incorrectア
b (power consumption = low) is correct, but treating a as fast is wrong. Since LPWA covers a wide area with low power, its communication speed is rather slow and does not become faster than a wireless LAN.
Incorrectイ
It treats a as fast and b as high, both of which are the opposite of LPWA's characteristics. LPWA is characterized by low speed and low power consumption, and describing power consumption as high contradicts its name Low Power.
- ウ
正解 LPWA (Low Power Wide Area), as its name suggests, is a wireless communication technology for IoT aimed at covering a wide area (Wide Area) with low power (Low Power). In exchange for reaching a wide range using little power, its communication speed (data transmission rate) is kept low, so compared with a wireless LAN its communication speed is slower (a = slow). On the other hand, its power consumption is small just as the name indicates, making it suitable for sensor devices that need to run on battery alone for a long time, so compared with a wireless LAN its power consumption is lower (b = low). Therefore the combination is a = slow and b = low, and the correct answer is ウ.
Incorrectエ
a (communication speed = slow) is correct, but treating b as high is wrong. The key point of LPWA is low power consumption (Low Power), and its power consumption never becomes higher than that of a wireless LAN.
ここがポイント
- LPWA (Low Power Wide Area) is a wireless communication technology for IoT that covers a wide range with low power consumption, and in exchange its communication speed is low.
- Compared with a wireless LAN, LPWA has a slower communication speed (a = slow) and lower power consumption (b = low). Its characteristics can be recalled from the name's Low Power and Wide Area.
用語