ADSL & Naked ADSL - Broadband Internet
Asymetric Digital Subscriber Line (ADSL) is one of the most common broadband solutions in Australia due to copper wire access already being available to most households and businesses. Optic fibre is slowly being rolled out via the National Broadband Network or NBN. ADSL is essential to regional areas where copper wire is the only network available.
ADSL uses multiple channels and transmits each channel at a higher frequecy than the "baseband" voice channel. This way it can support both digital signal and "plain old telephone service" (POTS) on a single pair line.
Think of it like radio or television channels, where the different channels are transmitted via the air on various frequencies. This is exactly like that, but instead the channels are transmitted down the copper whire.
This is known as frequency-division multiplexing (FDM). Using FDM the full bandwidth available in a communication medium (e.g copper wire, fibre optics etc.) is divided into a series of non-overlapping frequency sub-bands, each of which carries a separate signal. FDM in the optical fibre is known as wavelength-division multiplexing.
You may have heard people talking about Naked DSL as an alternative to using the standard ADSL plans available. The difference is the cost and how this suits your budget. Naked ADSL plans do not come with an associated voice phone number, so call costs are nil.
It is still possible to make phone calls using a Naked DSL line if you have a VOIP phone attached to your broadband modem.