IPA IP 2021 Question 80
A question IPA Japan published in 令和3年度 ITパスポート試験 公開問題 問80, translated into English. ITPEC is based on the same exams.
There is a temperature and humidity management system that consists of IoT devices, IoT gateways, and an IoT server. Which of the following is an appropriate specification of low-power wireless communication that is used to connect an IoT device and an IoT gateway installed near it?
Explanation
BLE (Bluetooth Low Energy) — the low-power part of the Bluetooth standard, used for short-range links between a device and a nearby gateway.
The IoT devices here are sensors measuring temperature and humidity: they send small amounts of data now and then and are often battery-powered. The link to a gateway installed nearby needs short-range, low-power wireless communication, which is what BLE provides. It was added to the Bluetooth specification for devices that must run for a long time on a small battery. The gateway then forwards the data to the IoT server over a wider network.
Answer (a)
Why not others:
- •(b) HEMS — Home Energy Management System, which monitors and controls the electricity use of household appliances; a system, not a wireless specification
- •(c) NUI — Natural User Interface, operation by gestures, voice or touch; a user interface concept, not a communication specification
- •(d) PLC — Power Line Communication, which sends data over electrical power lines; it is wired, not wireless
Key rule: For battery-powered IoT devices near a gateway, BLE gives short-range low-power wireless links; LPWA covers long distances at low power.
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.