Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I read that Broadband is distinguished from Baseband by using a greater range of frequencies in the electromagnetic spectrum and that ADSL divides the 1.1 MHz spectrum into 256 independent channels. However I don't really have a good mental image of what that means. Can anyone assist?

NB: Just to explain currently I'm thinking of it in terms of high or low voltages applied to a line and can't really see where frequencies would enter into it.

share|improve this question

2 Answers 2

up vote 2 down vote accepted

If you look at an audio spectrogram you'll see a bunch of different frequencies overlaid on top of each other. Each frequency is a pure sine wave, but they combine to create more complex sounds such as the strum of a guitar, the beat of a drum, or the sound of a voice.

If you compare this with, say, the tone used by a telegraph you'll notice that more information can be encoded since more than one frequency is in use, and each frequency has its own volume which adds to the whole.

share|improve this answer
    
Thanks Ignacio and Lo'oris. It begins to make sense now! –  Martin Smith May 15 '10 at 12:35

They are talking about audio frequencies.

That's the reason you need to insert a filter before your home phones if the ADSL is brought to you with the same line as the phone line.

share|improve this answer
2  
Well, no, they are electrical frequencies. They don't become audio frequencies until you stick it through a speaker. Not that there's any speakers that can handle 1.1 MHz though... –  Ignacio Vazquez-Abrams May 15 '10 at 11:59
    
oh.############ –  Lohoris May 15 '10 at 13:26

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.