Guide to ADSL and Cable Broadband - Part 1 of 3

Broadband provides faster internet speeds to homes at rates that are at least ten times faster than standard dial-up. With prices for broadband packages now as low as standard dial-up, the choice between the two is relatively easy.

However, there are also different types of broadband connection to choose between and these are broadly split into two categories – ADSL and cable. So how do these two types of broadband work, and is one superior to the other? This guide to ADSL and cable broadband will help you decide.

What is ADSL broadband and how does it work?

ADSL is an abbreviation of asymmetric digital subscriber line – which basically refers to broadband through a telephone line.

Unlike dial-up, which uses the phone line to make a connection, ADSL actually works alongside the frequencies used for voice telephone calling, therefore allowing you to continue to make phone calls while using the internet. It enables faster data transmission through a single connection, but allows users to download data and make voice calls at the same time.

The distinguishing factor of ADSL is that the flow of data is greater in one direction than it is in the other – hence the name ‘asymmetric’. This is why download speeds are far greater than upload speeds. Consequently, ADSL broadband is usually marketed towards passive internet customers who rely on downloads but have little emphasis on uploads. The top speeds for downloads are usually 8Mb, and the top speeds for uploads are usually below 1Mb.

ADSL broadband is widely available in the UK – with coverage accessible for more than 99% of the UK population. As such, the majority of homes in the UK have ADSL connections.

To make your ADSL connection work effectively you will need an ADSL modem and micro-filters. The micro-filters, which should be supplied by your internet service provider, prevent crackling on your phone line while you are using the internet. If you require more than one or two, they are usually available for just a few pounds.

ADSL modem routers rely on an upgraded BT telephone line. You plug the ADSL router directly into the BT phone line and there is no need for a separate modem – the broadband internet connection is then pushed to all computers within your home and within the wireless range. The only times you can receive an ADSL connection without a BT phone line is through a process called local loop unbundling in which providers offer an ADSL service without using a BT exchange, thus allowing them to be more competitive with the prices and services they offer.

Though you will generally require a BT phone line to use ADSL broadband, there are many different providers offering competitive packages to choose from. Check out our broadband comparison tool to find out more.