Kitz Forum
Broadband Related => Broadband Technology => Topic started by: Chrysalis on August 11, 2017, 05:47:18 PM
-
here
http://www.increasebroadbandspeed.co.uk/2014/vectoring-crosstalk-crisis
-
Interesting read, but unfortunately we all know that the vast majority of us are extremely unlikely to see vecoring on our lines.
-
Interesting read, but unfortunately we all know that the vast majority of us are extremely unlikely to see vecoring on our lines.
Indeed, especially those who are on second class service ECI DSLAM's I imagine :P.
-
Interesting reading but nothing new really as anyone in Southern Ireland can already vouch for the benefit of vectoring which Eircom had the foresight to implement from very early days.
The article appears to jump between references to SNR & SNRM, inferring that in this context a higher SNRM is more desirable and indicative of a less impacted line, higher SNR yes !
If the BT roll out of vectoring is anything like the G.Inp (retransmission) roll out then I certainly would not hold my breath in anticipation.
-
I stopped reading where it stated an impacted line is essentially a line suffering from crosstalk.
-
Indeed, especially those who are on second class service ECI DSLAM's I imagine :P.
ECI is third class, Huawei without vectoring is second class, BDUK Huawei with vectoring is first class ;)
I'm on a third class cabinet, further impeded I suspect by aluminum.
-
>> I stopped reading where it stated an impacted line is essentially a line suffering from crosstalk.
Because of the higher frequencies used, broadband signals are susceptible to a particular type of interference – known as ‘crosstalk’ – from other VDSL2 broadband signals being carried along adjacent pairs.
Not quite true either. ADSL & ADSL2+ suffers from crosstalk. Its nothing new and certainly not unique to VDSL
Over time I lost nearly 5Mbps due to crosstalk when on BE* shiny new MSAN I easily got 24/2.6 I lost quite a lot of it when O2 users were added and down to 19Mbps by the time FTTC became available. I could quite clearly see the cross-talk bump which centred around tones 280 on my line. There were no QLN graphs back then but someone experienced in reading line stats could spot it by looking at bitload and SNR per tone.(yes I do mean SNR, but SNRM works too) You'll find many references in my old posts talking about the U effect or crosstalk troughs as I called them on ADSL2+.
On QLN it shows as inverted U or crosstalk bumps. I still quite often double check and reference tones to bitload when looking for crosstalk just because old habits die hard and that is how I originally learnt to spot crosstalk way before FTTC became available.
Neighbouring ADSL/2+ lines can also affect VDSL. Can sometimes be seen on QLN & bitload in D1 tones, but VDSL PSD masking just makes it a bit harder to spot.
-
I've got vectoring :P
-
ECI is third class, Huawei without vectoring is second class, BDUK Huawei with vectoring is first class ;)
I'm on a third class cabinet, further impeded I suspect by aluminum.
heh you beat me to it with the comment.
Also yeah the site has some facts issues in the impacted rate etc but thought the attainable sync data was useful info.