How does broadband actually work?

Any fast, permanent internet service is called 'broadband', although there are various ways of getting broadband connected to your home.

Broadband can come via your phone line, a cable TV service, 3G mobile phone network or by satellite.

The most common method is via your phone line using a system called ADSL.

ADSL

ADSL uses the same cable that connects your phone to the local exchange.

However it does not stop you making or receiving phone calls.

This might seem odd, especially if you are used to a dial-up connection where you can't use the phone and the internet at the same time.

How ADSL works

Unsurprisingly, the telephone system was designed to carry the human voice along wires.

The sound of your voice is converted into small electric pulses which travel along the wire. These electric pulses are then converted back into sound at the other end, so the other person can hear you.

This happens in both directions so you can have a conversation.

During the 1980s, telephone engineers were experimenting with ways of sending video pictures over normal phone lines.

The trick was to create a new set of pulses, this time for video, which would travel down the wire along with the voice pulses. These new pulses were at such a high frequency, they would not interfere with the voice signal.

Unfortunately the infrastructure was not really in place at the time for video via telephone, but the idea of sending two signals together over a phone line was to have other possibilities.

Because the video pulses were originally designed to carry a lot of information, they were perfect for carrying digital signals, like internet data.

A tiny box called a 'microfilter' separates the two signals at your end, so you get a permanent internet connection and a normal phone service.

How Wi-Fi works

Wi-Fi provides exactly the same service as broadband but without the wires.

This is very useful if you have a laptop computer or handheld device as you can access the internet wherever you are in the house.

It works by converting the internet data into a radio signal which is then picked up by each computer in the house using a 'Wi-Fi adaptor'.

There are two types of Wi-Fi in use, an older version which has the snappy name of '802.11b'. This is very slow and has been replaced by the much better system called '802.11g'.

Although these names are hardly memorable, the 'b' and the 'g' are definitely looking out for if you're shopping around for a Wi-Fi system as the 'b' type should be avoided.

Cable

If you have a cable TV or telephone service, you may be able to get a broadband service from the same company.

If your cable provider supplies broadband, you will either get this through your set-top-box or via a new cable modem.

Your provider will help you find out how to sign up. Check their website for details.

Satellite

Satellite services are still in their infancy but either work via a 'one way' or 'two way' link.

The one way link works by a satellite sending information to your computer via a dish which costs about 90 pounds.

Unfortunately you cannot send information back to the satellite with this method so every time you click a link, your request is sent via a normal dial-up connection.

It does mean you can download information at high speed from the satellite to you, but you still need to have a phone line for it to work.

A two way system can transmit and receive data to the satellite. This means you don't need a phone line and can get a very fast connection (depending on weather conditions) but these systems are very expensive.

Typically about 1000 pounds to install the equipment and around 1000 pounds per month for the service.