Thread: "Wireless" network

Okay I have seen recently something about a "wireless" network. I use the term in exclamation marks as its not really wireless, but it utilises the MAINS POWER system in your house to transfer data. Basically you just plug into a mains socket and data will be transferred through the mains wires in your home.

My question is simple:

How the hell does this work ?

Are you sure thay use the mains? - I know some baby alarms do and power companies transmit control data superimposed on the high voltage grid, but I thought 'wireless' networks were small transmitters operating at about 2.4Ghz. If you have a link I like a look.

Yes I am.

Yes "wireless" networks do use transmitters at around 2.4ghz as u said, sorry for calling it wireless. its not, it just means you dont have to use additional network cabling, is what i meant, with the mains power network system.

I couldnt find out HOW they do it, hence my question. but ill give you one of the links for the equipment:

http://www.maplin.co.uk/Free_UK_Deli...t_46494_v2.htm

The mains is very low frequency 50 cylces per second (UK, 60 US). The network connection at 14MBPS will be transmitted at at least 28 Million cycles per second. Two frequencies so far apart are very easy to seperate electronically using capacitors and inductors, the mains system has a lot of 'resistance' at high frquency so the signals will not travel far. The Network signal is merely 'piggy backed' onto the mains. THe interesting thing is, if you have any really good RF filters on any of your equipment (unusual in most domestic stuff) the wireless signal may be severly attenuated.

THis is the same sort of system as some baby alarms use (you'll need one later :wink: and also if you have a 'masthead pre-amp' on your TV antenna using a single coax this will also use it.

The guy next door ought to easily be able to use your network free if he's switched on, if he has the same system as you, all sorts of things could happen. Best bet is always a direct wire link which by it's very nature, cannot be intercepted.

Okay thanks, that explains it, although im sure you're bound to get phase cancellation at some point ?

My broadband connection is wired via ethernet cable anyway. Also wireless BB that you can pick up now in quite a few different places. I see the future of BB in wireless technology. What i'd like to see is BB wireless to be delivered accross the existing cellular networks too. Not too sure if this would work ?

Phase cancelling? - not a problem the 50hz is filtered out so it becomes effectively a straight line.

Oh I see, rather like the micro-filters that filter out the normal telephone frequencies?

Yes a filter is a filter, in the case of the one we are discussing it is called a high pass filter, that is, it only allows high frequencies (the data channel) to pass.