A Guide to ADSL Broadband
ADSL stands for Asynchronous Digital Subscriber Line. This technology uses either copper or optic-fibre connectivity to combine Internet and telephone services and offers the benefit of sharing these functions without the cost of a second line. The term "Asynchronous" is used to indicate that the data upload is slower than the data download into the user's computer. To put the technology into context, other options are Cable, where the Internet is shared with TV broadcasts and Teletext; Wireless, where there are no physical connections between the user and the Internet, the signal being transmitted and received by wireless, just like a mobile phone and Satellite Broadband, where a dish hired or purchased by the user sends and receives the data from a satellite. The focus of this article is ADSL.
Relative to dial-up Internet, ADSL is like comparing an F1 racing car to an old Diesel truck. As an example, even with the current speeds available to most users, a 10 Mb file may be downloaded in less than 2 minutes, whereas on dial-up, come back after a long lunch and it just might have finished the download. Current ADSL is theoretically capable of delivering speeds of up to 8 Mb/s (Megabits per second) but in practice, much depends on proximity to the exchange, the load on the system at the time of use and the type/condition of the infrastructure.
Practical speeds are far lower than the theoretical limit and significantly less than is claimed by many Broadband suppliers. In January 2009 OFCOM found that around 45% of subscribers actually achieved speeds of less than 4 Mb/s. However, newer ADSL2+ technology is capable of pushing speeds at up to 24 Mb/s and this is being made available progressively to consumers.
Even ADSL2+ is still relatively slow compared to what will ultimately become available. The main problem currently is the cost of installing the optic fibre cable and even when this comes to the street, it usually connects to copper lines for the run into the office or dwelling. At the present time, very few users will have the luxury of optic fibre from the exchange right to the computer. The future is, however, looking very positive. As of May 2009, BT plans to double the availability of broadband fibre rollout, bringing up to 100 Mb/s broadband within reach of more than a million premises by 2012. When this occurs, a typical 30-minute TV show could be downloaded in less than 28 seconds.
In the current state of play, the choice of a service provider is the critical element in obtaining the best possible service and value. This is where the resellers offer major benefits to customers, by packaging deals that would not otherwise be readily available to the individual customer. Even so, it is wise to be realistic about what is of value and what is not, relative to how and when the service will be used.
A business customer, for example, may have peak usage between 9 and 3 daily with relatively small data transfers, whereas an individual doing on-line gaming at home might want peak speed and significant data downloads between 8 pm and midnight. The quantity of data to be transferred will play a major part in the decision because excess charges for over-use can be high, so a fixed rate deal may be of greater value than bonus products. The selection process will be made easier by reference to websites offering comparison of available Broadband packages.
