This question has nothing to do with linux. But as I am studying linux I figured why not ask here. The answer to my question may be really obvious to some but it is something I've yet to figure out.
I know that broadband is when multiple signels travel down a cable, such as a t1,2,3,4 connection or a lan isdn. But how can a coax cable that I've got with my NTL Broadband package possibly be broadband as the cable in my wall is a Coax Cable that only transmits one signal at a time?
I'm puzzled.

im not an engineer so have probably got this wrong but you can send many signals down the same wire by sending them at different frequencies eg

say you have two signals A(t) and B(t) that vary with time, i can easily produce the signal A(t)sin(t)+B(t)sin(2t), then i can send this signal down the wire

when this signal gets to the other end i can do some fourier analysis and i can work out the amplitude function of the 2pi periodic part which will be A and the amplitude of the pi periodic part which will be B hence reconstructing my two distinct signals

i can do the same thing with as many different signals as i want so i can send lots of different signals down the same wire.

I am an engineer and saddly I have been to embaressed to ask this question for a long time.
But does that mean that I can send more then one one package at the same time? For instance most packages with the tcp-ip protocol are around 1kb.
I know that ISDN is broadband because it has many wires in one cable, and I guess the same should apply to ethernet rj45, but coax as used in early ethernets i.e. cat 1,2, and token ring networks only has on wire inside the cable, therefor in theory atleast should be baseband.

The number of wires has nothing to do with it.

Just like there's only one atmosphere, but many radio stations playing through it...

Think of Fiber-Optics, as well. Fiber optic only needs one "wire", but it's just a channel for light to pass through. Many different signals at once can be passed using different frequencies.

--Shade

rj-45 only has 4 wires that are really used for transmitting signal, or at least thats how it is in phones and I assume the same when theyve been crimped that 4 carry signal and 4 carry power which is why you can it to power a handy single serving drink cooler...wish I still had that link...

So what is the definition of baseband and broadband? Do we measure packages or frequences when diciphering the osi model? Or, is BT/NTL broadband/baseband a joke or confirmation of a lame os?

apologies for last reply. i realise now that it does not make much sense. What I meant was is broadland when many frequences travel down the cable and baseband when only one frequency travels down a cable, like baseband? What I don't understand then is more than one signal travels down a modem rj45 cable and yet it is baseband?
I don't know what I was trying to say when I posted my previous reply.

Baseband is digital and uses TDM (time division multiplexing); broadband is analog and uses FDM (frequency division multiplexing.)

DUUUDE !!!!
think about it....
where have you seen COAX before ???
Yep... the cable that connects your analog TV into your Arial.

or my my case, analog cable tv.

i have about 50 TV channles, all traveling to my house via COAX.

all the different channels are carried down by different frequencies all on the same carrier wave. when you tune your TV into a channel, you are isolating one frequency (channel) from the rest on the carrier wave.

i assume this works the same way