Talk:ITU G.992.5

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Contents 1 3.5Mbps is not really true 2 3.0 Mbps is more realistic 3 need more 4 Bandwidth Efficiency and DMT 5 Bad web page 6 OFDM system comparison table 7 Image is incorrect 8 Image Incorrect

[edit] 3.5Mbps is not really true

That the max upstream rate is 3.5Mbps is not really true - there is a special annex, M, that defines double upstream. a plain normal adsl 2+ connection only has about 1.5 Mbps upstream rate. --69.233.166.166

[edit] 3.0 Mbps is more realistic

When tuning the right parameters made available with the ADSL2+ spec, you can achieve nearly 3.0 Mbps upstream rates with Annex M. You must carefully set targetSNRmargin, enable SRA for line stability and keep an eye on the PM stats to make sure you are not taking UncBK at a rate that exceeds your SES threshold for the service you are delivering. SNR=Signal to Noise Ration, SRA=Seamless Rate Adaption, UncBk=Uncorrected Blocks, SES=Severely Errored Seconds > 10E-7 as define by ATM forum.

[edit] need more

This article does not make much sense. How and why is the downstream rate so much higher than the upstream rate? And how is it possible for the "data speed rates" to be so much higher than the "transmission speed" frequency? 69.87.202.147 00:06, 4 December 2006 (UTC)

[edit] Bandwidth Efficiency and DMT

ADSL2+ uses a modulation system called Discrete Multi Tone (DMT). The 2.2MHz band is divided into 512 bin that are each 4KHz wide (with 6 KHz spacing). Each bin can transmit a 2-D constellation of 2-points (1-bit) up to 256-points (15 bits). The DMT frame is tranmitted every 250ns. Hence the higher rate - Do not confuse bandwidth with bit rate. The Bandwidth efficiency of DMT is much greater than 1:1 71.127.246.48 18:25, 1 February 2007 (UTC)

[edit] Bad web page

This web page is terrible. ADSL2+ is much advertised and talked about, but this web page is so bare, clinical and useless that I wonder why it is even here. What good is any of this gobble de gook to anyone? This page doesn't inform or delight me at all JayKeaton 07:18, 13 February 2007 (UTC)

[edit] OFDM system comparison table

Feel free to add an ADSL2+ column to the OFDM#OFDM system comparison table. Mange01 12:20, 17 July 2007 (UTC)

[edit] Image is incorrect

ADSL2 does use up to 12Mhz, but ADSL1 only uses up to 1.1Mhz. So the yellow portion is mislabelled. Please edit the second "ADSL2" label to say only "ADSL", while keeping original "ADSL2" label untouched. Mdrejhon (talk) 18:46, 11 February 2008 (UTC)

[edit] Image Incorrect

The image is indeed incorrect, but unlike Mdrejhon suggests, the 12MHz upper limit is incorrect. ADSL2+ tops at 2.2MHz —Preceding unsigned comment added by 213.246.227.244 (talk) 10:33, 21 February 2008 (UTC)