Wednesday, August 02, 2006

What is broadband?

Originally broadband was a term used for connections that supported data rates of at least 8Mbps – data rates that were suitable for transmitting full-screen broadcast quality video. Today, the term broadband has come to mean anything with speeds above 256kbps. However, the packages on offer today come close to the original broadband concept in offering data rates between 2 and 16Mbps.

The technology underlying the current service offerings for the home is ADSL (Asynchronous Digital Subscriber Line). The important aspect of ADSL to appreciate lies in the A for asynchronous. The 'asynchronous' label indicates that the inbound and outgoing data rates provided by the service are different – with higher speeds available for receiving than for sending data.

With the new ADSL service packages you will be able to download data – web pages, files, audio and video streams – at theoretically maximum speeds of between 2 and 8Mbps. In contrast, when you send data – like posting your holiday snaps on Flickr - the uploading speeds will seem slow.

Typically, a connection with a nominal 512kbps speed rating gives a download rate of around 460kbps and an upload rate of 200-240kbps. The upload rate remains the same for services nominally rated as 1 & 2Mbps. It is the 8Mbps services that show a significant increase – with upload speeds typically between 400 and 756kbps.

To complicate matters further, your broadband provider will be sharing your data stream with other users – for domestic users one data stream may be shared between up to 50 households. So if you all want to use your internet access at the same time, things will seem slower than you would expect. And should you all start uploading files at the same time, you will probably feel nostalgic for the speeds that you used to get out of your old-fashioned modem.

The current delivery of home broadband using the copper wire of the telephone line has been around for sometime, but it has life left in it yet. There are new versions on the way called ADSL2 and ADSL2+ and after that VDSL.

No comments: