"Michael Chapman" wrote: > You can (or could) get little boxes that plugged ino power points (as in > 220v sockets) that each had an (?)ethernet* socket. > A sort of poor man's WiFi for in the home ... except they weren't that > cheap. > > Did they allow a network (>two parties 'on line') ? > What was their range ? > Bandwidth? > Latency ? > > Suspect one had to be on the same phase of the power supply (it was that > _thought_ that caused us to abandon the query for a building with three > phase (well, with different halls on different phases)). > (You could possibly get round that by transmitting between neutral and > earth ... maybe they did anyway?)
I used to be on the board of a charity that wired up buildings for Internet, and we used these occasionally. The result was an Ethernet, so more than two parties worked fine. The range was several hundred metres. One of the limitations on this was the quality of the wiring, so precise figures are difficult. The bandwidth decreased with strength of signal (and so with distance), so that might be a problem. No idea about latency (this didn't interest us). The biggest problem was that the RF is blocked by transformers. In Canada, each floor of a building tends to have its own high-voltage feed. This meant that the Ethernet boxes could not communicate between floors. (Wi-fi also finds this difficult because the RF can't fit between the gaps between the rebar in the concrete floors.) Regards, Martin -- Martin J Leese E-mail: martin.leese stanfordalumni.org Web: http://members.tripod.com/martin_leese/ _______________________________________________ Sursound mailing list [email protected] https://mail.music.vt.edu/mailman/listinfo/sursound
