Broadband availability

ADSL BROADBAND ARRIVED ON 7th July 2004 and may now be ordered from any ISP.

If you order from:
Eclipse then please use the referrer code 'CAMELOT'.

Too far away from the exchange - can't get it?
From September 6, 2004, the reach limit for the 512kb/sec ADSL services was removed. BT is also increasing the range for 1Mb/sec premium services from 4km to approximately 6km – making 1Mb/sec ADSL available to 96 per cent of homes and businesses connected to a broadband exchange.

The trial data indicates that removing the limit means 99.8 per cent of lines connected to a broadband exchange should now be able to get a 512kb/sec or better ADSL service. To date approximately 96 per cent of homes and businesses connected to broadband enabled exchanges were within range for 512kb/sec ADSL.

Previously there was a limit for 512kb/sec broadband based on 60dB of signal loss on the line (typical line length about 6km). This meant 512kb/sec services reached approximately 96 per cent of homes and businesses.

The new line loss limit for 1Mb/sec ADSL will be 60dB (approximately 6km).

While the removal of reach limits for 512kb/sec ADSL will mean the vast majority of people connected to a broadband exchange will be able to get service there will still be some who can not, even following a visit by a BT engineer. The trial data indicates this should only apply to an average of 0.2 per cent of lines connected to broadband enabled exchanges.

Understanding Contention

It's important to understand contention. (BT don't talk about this much but the basic position is unchanged). When your telephone line is enabled for Broadband, BT connect your line into a piece of hardware (called a DSLAM) at the telephone exchange. This hardware is connected to the Broadband network. In a worst-case scenario, you might be sharing that piece of hardware with up to 49 other people, meaning that you are all sharing the same 512Kb/sec connection. This means your download speed could be poor, e.g. down as low as 10Kb/sec - worse than you get at the moment! However, in reality this doesn't happen for two reasons:

It's unlikely that you'll be sharing the hardware with 49 other people; not in a rural area like ours anyway! In reality this is probably nearer to 15 other people.
The nature of internet use is in "bursts". i.e. you download a web page, read it, download another; read it etc. As such, there are long pauses where you are not actually sending or receiving data. This allows many people to share the same resource.
So, if you're on a 512Kb connection, you can probably expect an average download speed of between 400Kb/sec and 480Kb/sec - in other words, almost maximum speed.
The contention ratio is one of the reasons for different pricing in similar services.

Connection Speed

Choosing a connection speed is not a major issue for most "home PC" users. On a dialup connection you're probably connecting to the internet at somewhere around 45Kb/sec. A Broadband package offering 512Kb/sec means you'll be connecting 11 times quicker; a 1Mb/sec package means you'll be connecting at 22 times the speed! But for most users of the PC this is not really an issues, as web pages will still appear to load instantly with both connection speeds mentioned.
For 90% of the users in this area, a provider offering a 512Kb to 1mb service will be perfectly adequate. Many of us will not be able to have a faster one in any case due to quality of the line!

Broadband uses ADSL (Asymmetric Digital Subscriber Link). The key word here is "Asymmetrical", meaning the line operates with a different transmit speed to the receive speed. So, when you see people quote a 512Kb link, or a 1Mb link, the this is the download speed, i.e. the speed at which web pages reach your computer; in all cases the upload speed is different - perhaps only 256Kb. In reality this is not a problem, since most of your internet use will probably be to receive data, i.e. look at web pages and receive email. On the other hand, if you send lots of data (e.g. large emails, data files etc.) then don't think that a 1Mb connection will be better than a 512Kb connection - it won't, your upload speed in both cases is only 256Kb or so.