問82
頻出度★★★
LANケーブルを介して端末に給電する技術はどれか。
平成26年度 秋期 ITパスポート試験 問82
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 82
Incorrectア
EUC (End User Computing) is the idea that the users themselves (the end users), rather than the information systems department, build and make use of the processing or systems their work needs, using tools such as spreadsheet software. It is a term about how an organization advances its use of information technology, and has nothing at all to do with supplying power.
Incorrectイ
IrDA is a standard for short-range wireless data communication using infrared light. It is a means of exchanging data without a cable, not a technology for supplying power.
- ウ
正解 The correct answer is “ウ”, PoE. PoE stands for Power over Ethernet, a technology that uses an Ethernet LAN cable (twisted-pair cable) to supply electric power to the device at the other end at the same time as it carries data. Power is sent from the power sourcing side (a PoE-capable switch or a PoE injector) to the powered side (a wireless LAN access point, an IP phone, a network camera, and so on), so even if there is no power outlet where the device is installed, a single LAN cable can provide both communication and power. In practice, the benefit is that it lowers the cost of installing devices in places where electrical wiring is difficult, such as ceilings or outdoors.
Incorrectエ
TCO (Total Cost of Ownership) is the idea of looking at cost as a total amount that includes not only the cost of introducing a system but also operation, maintenance, training, and disposal. It is a concept for evaluating cost, not a technical standard, so it has no connection with supplying power.
ここがポイント
- PoE (Power over Ethernet) = a technology that carries both communication and electric power over a LAN cable. It is used for wireless LAN access points, IP phones, network cameras, and the like in places where power is hard to obtain.
- For questions about alphabetic abbreviations, eliminate options by sorting them into fields. EUC is the use of information led by the user departments, IrDA is infrared wireless communication, and TCO is the cost concept of total cost of ownership; the only one that deals with supplying power is PoE.
用語