| Posted: Tuesday 3rd August 2004 by
Sam |
Amendment (17:40): Since publishing this article I have spoken to BT Wholesale and they 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, 361 (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). Only 19 of the 117 lines that required testing failed. This represents 3.9% of the overall figure.
I've also had a chance to see 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). |