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[Ronski]

I've had mine FTTC connection since 20 August 2012, and the downstream has fluctuated from 55 down to just over 40 at it's lowest, and I'm now enjoying 51.5Mbps. The upload on the other hand has gone from a high of 14.3 which lasted for around 3 days at the end of August 2012 down to my current US sync of 6.4Mbps.

Now this doesn't cause me any problems, but I've always wondered why the US has got so bad, whilst the DS has improved, obviously G.INP helped recently, but that only increased us from 47.5Mbps to the current 51.5Mbps.

I've posted some graphs to Dropbox, the earliest line states, and the lastest, also a graph which covers the entire period showing my sync and attainable.

https://www.dropbox.com/sh/lamp2cyxslih79m/AABsaZ_ZKk6ScJld-26qLbsRa?dl=0

[NewtronStar]

G.INP on the upstream was way better than this fastpath fix on the huawei Mk2  the max US attainable was higher and the US sync rate was also higher and stable

After the change from G.INP Mk1 to Mk2 the upstream has become less important in the eyes of BTw the end-users are starting to feel the affects of neglect, who decides the download is more important than the upload

[S.Stephenson]

It's only going to get worse for the upstream if the rumors are true.

[Dray]

Which rumours?

[S.Stephenson]

Wasn't there talk of them taking frequency from the upload and reassigning it to the down.

[forceware]

I really hope not, I've only got .5 up

[Dray]

where was that reported?

[loonylion]

Wasn't there talk of them taking frequency from the upload and reassigning it to the down.

I think you're confusing it with G.Fast, which is capable of dynamic frequency reallocation.

[S.Stephenson]

I swear I read that somewhere 

May have been G.Fast though, I'll have a look around and try to remember.

I remember something along the lines of upload provision was above what people are using and something about a 8:1 ratio but this is just a faint memory.

[forceware]

You are correct, you read it in the openreach data usage report. They didn't say they would implement anything though.

[S.Stephenson]

So could tones used for upload be repurposed theoretically for download?

I think there was discussion about what gains could be made from doing this but my memory is vague.

[WWWombat]

but I've always wondered why the US has got so bad, whilst the DS has improved, obviously G.INP helped recently, but that only increased us from 47.5Mbps to the current 51.5Mbps.

The obvious first answer is because you have so much less bitloading in U1 and U2. Less obvious is why.

Comparing the two outputs from --pbParams suggests that the power in U1 and U2 have both dropped by ~ 3dB. That alone would account for 1 bit on each of the tones through both the U1 and U2 bands. But that still isn't enough.

I can't compare the QLN data for upstream, because the old graphs don't include it. However, we can see that QLN in the surrounding downstream bands has increased markedly - so more crosstalk. It is likely this has had an impact on upstream too.

[Ronski]

Thanks WWWombat, cross talk is what I've always thought, but apart from the very early days where I briefly got 55Mbps my download seems to have improved over the years, surely cross talk would have taken it's toll on the download as well? It's almost as if the faster download I get the slower my upload goes.

If anybody want's to see any other graphs I can add them to the Dropbox folder.

[niemand]

So could tones used for upload be repurposed theoretically for download?

I think there was discussion about what gains could be made from doing this but my memory is vague.

Theoretically but not permitted with the ANFP as it stands at the moment.

Just FYI G.fast doesn't allow for dynamic frequency allocation as it doesn't have one. All the bandwidth is either used for upstream or downstream, it relies on time division rather than frequency division to split them.

[Chrysalis]

ronski there is a guy with a 890m on sky forums line with just bit lower sync than yourself.