IPA IP 2023 Question 87
A question IPA Japan published in 令和5年度 ITパスポート試験 公開問題 問87, translated into English. ITPEC is based on the same exams.
Which of the following is a technology that is also used in IoT area networks and that uses power lines also as a transmission path by superimposing high-frequency communication signals on the power lines that supply electricity and transmitting them?
Explanation
PLC (Power Line Communication) — sends communication signals over the power lines that already supply electricity.
PLC superimposes a high-frequency signal on the electric wiring, so any power outlet becomes a network connection point and no new cables are needed. In IoT area networks it links devices such as smart meters, home appliances and equipment in a building through the existing wiring.
Answer (a)
Why not others:
- •(b) PoE — Power over Ethernet works the other way round: it supplies electric power over a LAN cable to devices such as access points and network cameras
- •(c) Energy harvesting — collects small amounts of energy from light, heat, vibration or radio waves around a device to power it; it is not a transmission path
- •(d) Tethering — lets a PC or other device reach the Internet through a smartphone's mobile connection
Key rule: PLC = data over power lines; PoE = power over LAN cables. Read which of the two the cable is mainly for.
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.