IPA IP 2025 Question 56
A question IPA Japan published in 令和7年度 ITパスポート試験 公開問題 問56, translated into English. ITPEC is based on the same exams.
Which of the following is one of the specifications added to Bluetooth, has excellent power saving characteristics that enable an IoT system to be operated for a long period, and is also used to find the distance between transmitting and receiving devices?
Explanation
BLE — Bluetooth Low Energy, the low-power specification added to Bluetooth in version 4.0.
BLE sends small amounts of data in short bursts and sleeps in between, so a sensor or beacon can run for months or years on a coin battery. That suits IoT devices that must operate for a long time without maintenance. A receiver can estimate how far away a BLE device is from the strength of its received signal, which is how beacons tell a smartphone that it is near a shop shelf or an exhibit, and later versions add direction finding.
Answer (a)
Why not others:
- •(b) IrDA — short-range communication by infrared light, which needs the devices to face each other; it is not part of Bluetooth
- •(c) NFC — contactless communication over a few centimetres, used in IC cards and smartphone payment; it is a separate standard
- •(d) PLC — power line communication sends data over electric power lines; it is wired, not a Bluetooth specification
Key rule: BLE is Bluetooth’s low-energy mode for IoT sensors and beacons; LPWA covers kilometres at low power, NFC a few centimetres, IrDA uses infrared.
Networks · AI-written, may contain errors
This question comes from the past questions IPA Japan publishes, translated into English by ITPEC Practice. ITPEC Practice is an independent study tool and is not affiliated with IPA or ITPEC. See the original paper (PDF) or Report an issue.