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Too far away from the exchange - can't get it?
The basic BT requirement was that you must be under 6.5km from the exchange. Cable distance ... not road! This is to be certain of the quality of the copper wires to take broadband. The more critical issue is ‘line loss’ i.e. the amount of loss of noise on the line – which increases with distance. The limit was 60db. This has changed from 6.9.04 - see below.
The 6.5km distance was raised following a BT 10km trial in Milton Keynes on Jun 1 2004.
Early trial results:
Trialling via 23 ISP. 384 trial installations with 14 failures.
See:
www.anotherurl.com/monkston
www.mkweb.co.uk/broadband
Typically an engineer will change the BT faceplate and check the wiring for problems including interference.
Likely outcome:
Line loss will be raised to 65 or even 70db. By implication the distance will be raised to around 8km. If you want over 512 speed it should be possible at further distances. Out of 10,000 lines in Milton Keynes currently unable to get it the number is likely to drop to just 200.
As far as I know to get maximum ADSL speed (1 or 2mb) you will need to be under 3.5km from the exchange witha 40Db loss. This is BT wire distance - not road or as the crow flies. If you are over 3.5km to 6km you can probably get RADSL.
RADSL will allow users to get connected at distances up to 6km. It is still heavily dependent upon the WOOOSH test and you may still fail if your line has a large amount of signal loss on it. When I last heard, the limit is 59dB, for previous ADSL installs it was 45dB. The maximum speed for RADSL is 512 kbs
Customers who failed the ADSL line tests by a small margin should not have any problems obtaining an RADSL connection.
We are likely to still see all sorts of anomolies. e.g. neighbours where one gets 2mb and another who gets the message that there is no service. BT notoriously rely on the auto line test and are very reluctant to make a manual check - but see below for news. If you feel that there are genuine grounds for complaint then BT said: If you want a further check done on a line that gives the 'too far away' message, please email btw.broadband.deployment@bt.com |
Preliminary Milton Keynes extended reach trial results
BT Wholesale have asked me to reiterate the fact that none of this is yet confirmed. However, I have been told that an official announcement is due in the very near future.
Although the Milton Keynes trials are set to run until the end of September, ISP's have already been briefed by BT Wholesale with some early results and proposals.
The results are quite staggering. A total of 478 lines were provided under the trial, which operated primarily in Milton Keynes, but also at two remote Scottish exchanges and in Cheltenham. Of these 478 lines, 342 (76%) worked first time without any intervention from BT. 117 (24%) of them required an engineer visit (to further diagnose the line, and install an ADSL faceplate if required) and only 19 (3.9%) failed.
There are some rather interesting graphs. These show the vast majority of 512Kbps lines working up to around 75dB line loss. After this point, the number of engineer visits and failed lines increased significantly. However, there was the odd line that far exceeded 75dB, and even came close to 100dB!
Another graph showed the phenomenal difference between a face-plate install and a wires-only install. To give you an idea of the difference, at 60dB line loss on a 1Mbps line, 9% of wires-only connections failed, whereas only 2.5% of those with faceplates failed.
Whilst no firm new limits have yet been set, the following limits were proposed by BT Wholesale:
Increase the "Green" limit for 512K lines to 75dB. All lines above this limit will be tested for viability after ordering though. If the line is above the limit, but could receive ADSL with a faceplate, then one will be supplied free of charge by BT.
Leave 2Mbps alone at 41dB line loss for now.
Please note that none of this is set in stone, and the official findings of the trial will not be announced until sometime after September 30th 2004 (when the trials end). |
NEWS RELEASE 18.8.04
BT today announced it is removing the distance related limits for the most popular broadband services, bringing potentially more than a million more UK homes and businesses within reach of broadband.
Following BT Wholesale trials in Milton Keynes and rural areas around Fort William and Dingwall in the Scottish Highlands, BT is confident a 512kb/sec ADSL service can now be provided to the vast majority of people beyond the former limit which was roughly equivalent to 6km distance from the exchange.
From September 6, 2004, the reach limit for the 512kb/sec ADSL services will be 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 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). The line loss limit for 2Mbps will continue to be 40dB
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.
If an engineer needs to visit then it will be arranged by your ISP and there will be no charge for the visit, or for the fitting of a new faceplate. This will also include the provision of upto 30m of CAT5 cable so that the ADSL modem can be situated in a suitable location. The engineer will also check the state of the customers extension wiring, and if this is at fault, they will offer to rectify the problem for a fee, or disconnect it so that you can have functioning ADSL. The engineers will also look at possibly swapping your line to a shorter or better cable so you can receive a service, though this will not always be possible. |
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