Types of broadband

One of the first decisions to be made is what kind of connection you want. There are several options for setting up high-speed services, which all come under the broadband umbrella. However, the type of broadband service you need and have access to will be determined by your speed requirements, budget, and the location (city or regional) of your home or office.

ISDN

Prior to the advent of DSL there were not many high-speed solutions for the home or office. One such is ISDN (Integrated services digital network) which is a dial-up symmetrical service which allows speeds from 64Kbps to 128Kbps. Dedicated ISDN lines can reach up to 256Kbps. The problem with ISDN is that it is incredibly expensive, especially in light of current broadband pricing available today. Nor is it as quick as cable or DSL.

DSL

At a glance

An Asymmetric Digital Subscriber Line (ADSL) uses your phone line to connect to the Internet through digital modem technology. It can reach varying speeds (the larger the number, the faster the service), and is superior to all other connection methods when running at its fastest maximum speed. Installation is quite simple, with monthly subscription costs becoming more affordable by the day. However, it is important to go with an Internet Service Provider with a proven track record, as connection issues can still plague customers in this sector. (In other words, try to avoid 'Backyard' ISP companies that you've never heard of.)

Telephone networks were never intended to carry data at high speeds; they were initially built to carry an analogue voice by converting your voice into an electrical signal. A modem converts digital signals into an analogue audio signal that can easily be carried over a phone line. The technical limitations of phone lines mean that the fastest they can carry a signal is around 56Kbps.

DSL (digital subscriber line) technology gets around this problem by using the phone line to carry digital signals directly, without converting them to an analogue signal first. This has three advantages: it allows much higher data rates than a regular modem; the connection is always on, which means that you don't need to dial-up each time you want to use the Internet (and incur another cost); and, because the copper wire is split at the exchange, you can use your home phone while on the Internet. ADSL leaves the frequency spectrum between 0kHz and 4kHz free for your telephone service and uses 20kHz to 2.2MHz for data transfer over the copper line. In other words, one phone line will suffice.