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Can someone explain broadband delivery by phone line?

  • 27-11-2006 1:33pm
    #1
    Jackie laughlin
    Closed Accounts Posts: 1,127 ✭✭✭


    I know that the bandwidth of a twisted pair is, say, 15 KHz. I therefore can't be getting a broadband connection to this PC. I'm getting the appearance of broadband through some method of encoding. How is it done?


Comments

  • #2
    liamo
    Registered Users, Registered Users 2 Posts: 1,193 ✭✭✭liamo


    The first place to look is Wikipedia.


  • #3
    Jackie laughlin
    Closed Accounts Posts: 1,127 ✭✭✭Jackie laughlin


    Liamo,
    The last place to look is Wikipedia. I gave up on it ages ago. It has just too many errors and contains too much ill-informed nonsense. I remember when I thought it a wonderful innovation but it has been ruined by contributors who don't know their subjects.


    It has become so bad that most teachers/lecturers advise students to steer clear of it.


  • #4
    sceptre
    Registered Users, Registered Users 2 Posts: 19,608 ✭✭✭✭sceptre


    Jackie laughlin wrote:
    The last place to look is Wikipedia.
    I wouldn't say it's true in this case (or for most IT-related topics).

    (edit, I had something about bandwidth and hertz here but it's pointless my discussing baud and channel capacity when the wiki article does it adequately)

    Personally I'd read the article liamo linked to, it gives a relatively good overview of how xDSL tech works and it'll enable you to come back with particular questions.


  • #5
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 93,601 Mod ✭✭✭✭Capt'n Midnight


    Jackie laughlin wrote:
    Liamo,
    The last place to look is Wikipedia. I gave up on it ages ago. It has just too many errors and contains too much ill-informed nonsense.
    ...
    It has become so bad that most teachers/lecturers advise students to steer clear of it.
    Still the first port of call, it's not definitive, but a very quick way to have a rough overview and some buzzwords to put into google.

    If you know a better source please let the rest of us know,

    As you well know GIGABIT networks run over twisted pair so the real limit is actually a tad higher. Hint: 10 Gigabit over twisted pair is being iorned out.
    BUT the bandwidth on a phone line is NOT 15KHz its only 1/5 of that, and that's because of ARTIFICIAL limits imposed by filters and restrictions of the A to D converters used by the phone companies, because a very long time ago 18?? they figured out how to put more than one call on a line and thus save money.

    imagine someone too lazy to lookup wikipedia :rolleyes:


  • #6
    Jackie laughlin
    Closed Accounts Posts: 1,127 ✭✭✭Jackie laughlin


    Liamo,
    I owe you an apology. I didn't use your link as I thought it simply a link to Wickipedia. I now realise that you were directing me to something specific. Thank you. I have to rush off now but I've marked the piece for later.

    I'll take the word of you people more up to date in technical stuff that Wiki is generally reliable in this area. However, try researching the history of, say, Section 31 in Irish Broadcasting and count the errors! Once one's faith in a source is gone, it cannot be restored.

    Captain, I know agreat deal about filters and I'm well aware of 3K speech channels. My reluctance to consult Wiki was far more serious than laziness.


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