Internet via electrical sockets

Question

There are new ads of an ISP in our neighborhood about their new internet service through electrical sockets in our houses. The price is a bit lower than ADSL. What is this system? What is the difference from normal DSL?

Answer 1

No, it's real. They've been talking about it for a while: they usually call it "BPL" for Broadband over Power Lines. It's more common in Europe than in the US.

The pluses are it works, and the infrastructure is cheap.

The minuses are that, given our crappy power infrastructure, ymmv, and current implementations are very noisy -- they spew interference in all sorts of frequencies. In particular it interferes with common ham radio frequencies, and ham geeks are very vocal.

Answer 2

There have been several different methods for for superimposing data on an AC power line. It is much like encoding voice signals on a radio carrier wave. Here is a Wikipedia article.

The main difference is that it does not use a separate cable coming to your home. It uses the existing power lines that feed electricity to your home. Generally speaking the connection speed and quality will be less then using an actual cable. It also requires a special "modem" to receive the transmit the data stream.

Answer 3

The differences between this system and ADSL are:

• It does not have the distance versus throughput limitations of ADSL, and
• It indirectly feeds the power monopoly, instead of directly feeds the phone monopoly.

When comparing, look at actual ADSL throughput, not theoretical/best-case. Actual throughput is determined by the physical wiring distance to your phone company's switch.