Broadband

What is it?

Broadband is a means of providing fast Internet connections down existing phone lines; specifically, this page is about getting broadband on BT phone lines in the UK.  This uses a technology known as ADSL.

Why would I want it?

Compared with using a "dial-up" connection to the Internet, broadband:

• Is "always on" — you can be permanently connected to the Internet, there is no need to dial a phone number or make a phone call.
• Works alongside your phone — the phone line can be used to make and receive phone calls at the same time as it is being used to connect your computer to the Internet; the two things (phone calls and Internet connection) are completely independent of each other.
• Is faster; most broadband connections work at about ten times the speed of a dial-up connection.

How does it work?

Essentially, broadband uses your existing phone wires to send extra, high-pitched signals between a device at your end and your local phone exchange.

Think of it like this:

The phone uses the phone line to connect to the phone network, and the computer uses the phone line to connect to the Internet, but because they use different frequencies they can both use the line at the same time and neither interferes with the other.

It's as if they both have their own separate line, although in fact they both share your existing BT line.

You need equipment at your end to turn the computer data into suitable high-frequency signals for the phone line, and BT provide equipment in the phone exchange to separate the phone signal from the computer signal and send each to the appropriate network (the phone network or the Internet).

What equipment do I need?

As well as getting your phone line "broadband-enabled" (of which more later) you need to buy two things:

1. An ADSL device.  This is the thing which turns the data from your computer into ADSL signals which can travel down the phone line and translates any incoming signals from the phone line into computer data.  It can be either an ADSL modem, or an ADSL router.  More on that here.

2. One or more microfilters.  These are also called splitters, and you need one of these for every phone socket in your house, whether or not you intend to plug a computer into that socket.  It performs two functions:

• it provides the right sort of socket to plug the ADSL device into (the ADSL device will have an American phone plug fitted), and 
• it contains a filter which prevents the high pitched computer signals from affecting your phone and makes sure the phone can't interfere with the computer signals.

Finally, let's look briefly at the other end — the phone exchange end.

At the exchange the high-frequency ADSL signals are converted back to computer data, and must now be sent to the Internet.  To achieve this, a link exists between the BT phone exchange and an Internet Service Provider, or ISP, who is responsible for providing Internet connections.  It's important to note that although the phone exchange is owned by BT, there is no reason why the ISP also needs to be BT.  So long as the ISP has an agreement with BT to send and receive data to and from the exchanges, there's no reason why any organisation can't perform this function, and indeed, many do.

When you order broadband, you order it from the ISP, not from BT.  The ISP is then responsible for liaising with BT to make sure your phone line becomes broadband-enabled and any necessary work is done in the exchange.  Nothing needs to be done to your line, and no-one will call at your house or install any equipment at your end.

There are several dozen ISPs offering ADSL on BT phone lines.  Confusingly, BT also runs two ISPs of its own, and of course these also offer ADSL, but  there is no necessity to choose either of these rather than any other ISP.  They are prevented by the telecoms regulator from having any different relationship with the rest of BT than any other ISP can have.

See choosing a good Internet Service Provider for more advice.

If this all seems a bit complicated, I can sort all this out for you, advise you on a good ISP, put your broadband order in, order and install the equipment you need at your end, configure your computer, set everything up and show you how it all works.

See the services I offer.

© Copyright  Paul Doherty, 2004.  All rights reserved.