Kitz ADSL Broadband Information
adsl spacer  
Support this site
Home Broadband ISPs Tech Routers Wiki Forum
 
     
   Compare ISP   Rate your ISP
 
Please login or register.

Login with username, password and session length
Advanced search  

News:

Author Topic: Very low noise on tones 415-468  (Read 1330 times)

konrado5

  • Reg Member
  • ***
  • Posts: 794
Very low noise on tones 415-468
« on: October 18, 2017, 02:14:36 PM »

Is it real that noise is so low? I know that other people don't use these frequiences (no crosstalk) but it seems the noise is still incredibly low.

Best regards
konrado5
Logged

burakkucat

  • Global Moderator
  • Senior Kitizen
  • *
  • Posts: 20951
  • Over the Rainbow
    • The ELRepo Project
Re: Very low noise on tones 415-468
« Reply #1 on: October 18, 2017, 05:29:58 PM »

It is generally accepted that a good noise floor, for an xDSL circuit, would be around -140 dBm/Hz per sub-carrier or quieter.

If only that level was maintained across the entire bandwidth . . .
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

konrado5

  • Reg Member
  • ***
  • Posts: 794
Re: Very low noise on tones 415-468
« Reply #2 on: October 19, 2017, 05:04:31 PM »

What do you think about this huge difference between tones 415-468 and remaining tones?
Logged

JGO

  • Reg Member
  • ***
  • Posts: 708
Re: Very low noise on tones 415-468
« Reply #3 on: October 19, 2017, 07:06:03 PM »

"What do you think about this huge difference between tones 415-468 and remaining tones ? "

Frequency Allocations - they are not made with IT in mind !.
Logged

konrado5

  • Reg Member
  • ***
  • Posts: 794
Re: Very low noise on tones 415-468
« Reply #4 on: October 19, 2017, 07:22:24 PM »

"What do you think about this huge difference between tones 415-468 and remaining tones ? "

Frequency Allocations - they are not made with IT in mind !.
I don't understand. I know that I am only user using frequiences 1.8-2.0 Mhz. My ISP disabled ham band mask for me.
Logged

burakkucat

  • Global Moderator
  • Senior Kitizen
  • *
  • Posts: 20951
  • Over the Rainbow
    • The ELRepo Project
Re: Very low noise on tones 415-468
« Reply #5 on: October 19, 2017, 09:45:43 PM »

What do you think about this huge difference between tones 415-468 and remaining tones?

That is something I am unable to explain. Perhaps you will discover something that fits your observations.
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

konrado5

  • Reg Member
  • ***
  • Posts: 794
Re: Very low noise on tones 415-468
« Reply #6 on: October 19, 2017, 10:31:37 PM »

That is something I am unable to explain. Perhaps you will discover something that fits your observations.
Crosstalk? Other people have HAM band masks.
Logged

burakkucat

  • Global Moderator
  • Senior Kitizen
  • *
  • Posts: 20951
  • Over the Rainbow
    • The ELRepo Project
Re: Very low noise on tones 415-468
« Reply #7 on: October 19, 2017, 10:52:32 PM »

Crosstalk? Other people have HAM band masks.

Well, yes, that is the simplest explanation that fits the observation.
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

kitz

  • Administrator
  • Senior Kitizen
  • *
  • Posts: 30725
  • Trinity: Most guys do.
    • http://www.kitz.co.uk
Re: Very low noise on tones 415-468
« Reply #8 on: October 20, 2017, 10:32:52 PM »

Crosstalk - or rather lack of over those tones. 

Your bit load graph would be interesting too.   
Logged
Please do not PM me with queries for broadband help as I may not be able to respond.
-----
How to get your router line stats :: ADSL Exchange Checker

burakkucat

  • Global Moderator
  • Senior Kitizen
  • *
  • Posts: 20951
  • Over the Rainbow
    • The ELRepo Project
Re: Very low noise on tones 415-468
« Reply #9 on: October 20, 2017, 11:05:06 PM »

Your bit load graph would be interesting too.

Oh, yes. That, too, would be interesting.

Actually the SNR v sub-carrier plot gives quite a good idea of the "excess" SNR that is available across that 200 kHz band. By eye, we can judge where a flattened sinusoid that links the two frequencies would lie. Everything above that would be the bonus "excess" due to the lack of other users. Whether the "excess" could then be mapped across the entire bandwidth, to give an estimate for a "one user system", I'm not too sure.
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

konrado5

  • Reg Member
  • ***
  • Posts: 794
Re: Very low noise on tones 415-468
« Reply #10 on: October 22, 2017, 06:28:36 PM »

This is my bit-loading on SNR margin 2.7 dB.
Logged