What is Broadband? A Beginner's Guide

Changing from dial-up to broadband is like waking up one morning and finding that your local B road has been transformed into an eight-lane motorway. Broadband is both faster and more efficient than dial-up and is really the only way forward for all, save the most casual of users. Whether it's watching a repeat BBC broadcast, tuning into an online radio station or computer gaming, a broadband connection can only enhance your internet experience.

The name broadband is a contraction of broad bandwidth, a term that is used to describe a two-way, high capacity link that is able to support full-motion, interactive video. Broadband uses your telephone line but splits the line into two parts. A connection is capable of handling higher frequencies than those that are necessary for the highest grade voice transmissions. Any voice communication initiated by traditional telephony is carried along the lower frequencies whilst data is transmitted along the higher frequencies. The two can be transmitted simultaneously so your regular telephone connection is not interrupted when you are connected to the internet….a definite plus if you have teenaged children!

Even though a broadband connection is much faster than dial-up, it is still an analog connection because it uses the telephone line. Essentially what happens when you get broadband is that one regular telephone line is divided into several different channels. To use the road analogy again, even though the motorway is divided into eight lanes, it is still a road, just as the B road is a road. Each of the lanes is its own channel. Your telephone calls are transmitted in the slow lane and data is transmitted in the fast lanes.

The term broadband generally refers to a connection that is 2Mbps or faster. The speed is calculated according to the amount of data that can be transferred in a specific unit of time. In this case, the unit is Mega bits per second. This transfer rate is sometimes expressed using kilobits per second and one Megabit equals roughly 1000 kilobits. It is good to keep these units in mind when you are comparing providers rates so you can convert the figures to a common denominator.

The cable used to connect the modem to your computer is fibre optic in order to increase available bandwidth for communication. The cable used to transfer the signal from the local exchange, however, is made from copper wire. Copper wire is not as conductive as fibre optic cable and the signal weakens considerably as the distance from the transmission increases. Therefore, the further your house is physically located from the exchange, the weaker the signal will be. The maximum distance one can be from the exchange and still have a strong enough signal is 3½ miles. Approximately 95% of British households are within this distance and are able to have a broadband connection should they so wish. If you live in a rural area and are unsure about the suitability of your location, it is best to ring either your intended service provider or BT to find out if you house is eligible.

An outline of all the different parts of the broadband system follows below.

Computer: your computer is the broadband gateway. A fast machine will be able to handle the downloaded data more efficiently but processing speed is not of paramount importance as nearly all computers that are less than three years old should be compatible with a broadband connection. Also, both Mac and PC computers can be connected. It is important to tell your service provider if you are using Mac as sometimes a different modem is required. Your computer is number one in the connection chain.

Modem: the ASDL modem is necessary for sending and receiving information at the accelerated broadband speed. It is wise to check with your service provider as many companies include the modem as part of their introductory package. If a modem is not included, not to worry as they are readily available at any computer shop. Again, Mac users will have to check to see if the free modem is compatible with OSX. The modem is second piece of equipment in the connection chain.

Micro-filter: this piece of equipment, also called a splitter, is responsible for dividing the telephone line into voice and data. Without the micro-filter, you would not be able to use the telephone while connected to the internet. Like the modem, the micro-filter is often included in the introductory package by your service provider. If it isn't, they are inexpensively available at any computer shop. The micro-filter is number three in the connection chain. One end is plugged directly in to the telephone socket whilst the other end receives both the cable from telephone and the one from the modem. Once all this is connected, you are ready to surf!