IPA FE Subject A sample Question 25
A question IPA Japan published in 基本情報技術者試験 科目A サンプル問題 問25, translated into English. ITPEC is based on the same exams.
Which of the following is a wireless communication technology used in IoT, and is used for a network called a wireless PAN (Personal Area Network) in which IT devices at a short distance communicate with each other?
Explanation
BLE (Bluetooth Low Energy) — a short-range, low-power radio standard for linking nearby devices, which is what a wireless PAN is.
A PAN (Personal Area Network) covers the few metres around a person: a phone with a smartwatch, earphones, a heart-rate sensor or a smart lock. Bluetooth is the typical wireless PAN technology, and BLE is its low-energy version, built to send small amounts of data now and then so that an IoT sensor can run for months or years on a coin battery.
Answer (a)
Why not others:
- •(b) — LTE is a mobile-phone (cellular) network covering wide areas through base stations, not short-range communication between nearby devices
- •(c) — PLC sends data over the electric power lines in a building; it is wired, not wireless
- •(d) — PPP is a data link protocol for a point-to-point link such as a dial-up or leased line, not a wireless technology
Key rule: Match the network to its range: PAN (Bluetooth, BLE, ZigBee) for metres, LAN (Wi-Fi) for a building, LPWA (LoRaWAN, Sigfox) and cellular (LTE, 5G) for wide areas.
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.