Kitz Forum

Broadband Related => Broadband Technology => Topic started by: Weaver on February 14, 2022, 09:32:38 AM

Title: Pilot tone placement in ADSL and VDSL2
Post by: Weaver on February 14, 2022, 09:32:38 AM
Pilot tones are a problem. I am unaware of any definitive statements with regards to their size and placing within the bandwidth of an xDSL circuit.

Nor am I. Can anyone help us out? Where does the pilot tone go?
Title: Re: Pilot tone placement in ADSL and VDSL2
Post by: parkdale on February 14, 2022, 04:51:42 PM
I don't think there's any particular point they use, but I have noticed a higher bit rate = more speed I could get?
Title: Re: Pilot tone placement in ADSL and VDSL2
Post by: Reformed on February 14, 2022, 08:48:46 PM
Nor am I. Can anyone help us out? Where does the pilot tone go?

Wherever the DSLAM likes the look of.

In happier news they are going away as the switch from analogue to digital continues.
Title: Re: Pilot tone placement in ADSL and VDSL2
Post by: tonygibbs16 on April 08, 2022, 04:07:27 PM
Hi all,

From looking at ITU-T recommendation G.993.2 (02/2019), see https://www.itu.int/itu-t/recommendations/rec.aspx?rec=13747 , section 10.4.5.1 , it seems to be the subscriber end (VTU-R) that decides when Pilot Tones are wanted in order to help with synchronisation.

It does not seem like it is the DSLAM that decides.

Cheers,
     Tony
Title: Re: Pilot tone placement in ADSL and VDSL2
Post by: Weaver on April 08, 2022, 06:20:12 PM
Thank you for spotting that. ;D. I’ll also take a look in G.992.3 as that’s what I’m running.