cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 
Highlighted
Aspiring Contributor
1,622 Views
Message 1 of 8

Noise Margin and Max Data Rate

Hi, we purchased BT infinity option 2 in January and everything has been good except for the home hub rebooting that has been mentioned on this forum.

What I would like to know is that I have noticed my noise margin has been slowly decreasing over the last few months which is also decreasing the max data rate too, does anyone know if this is normal for infinty?  (noise margin was around 9db down when we first got it installed)      

 

RSHub-NoiseMargin-20140325-150856.jpgRSHub-Max Rate-20140325-150857.jpg

0 Ratings
7 REPLIES 7
Highlighted
Distinguished Expert
1,610 Views
Message 2 of 8

Re: Noise Margin and Max Data Rate

Cross-talk increases as more people go live on your cabinet. BT are looking at Vectoring as a possible solution.
--
To say thanks for a helpful answer, please click the white star
0 Ratings
Highlighted
Recognised Expert
1,595 Views
Message 3 of 8

Re: Noise Margin and Max Data Rate

Crosstalk at work. I used to have a max rate of about 100mbps. Over the years as more people have taken up fibre my max rate has dropped to below 80 where sync rates are now being effected 😞

0 Ratings
Highlighted
Expert
1,557 Views
Message 4 of 8

Re: Noise Margin and Max Data Rate

Your Max rate has not dropped that much and at least your SNRM is just above the target margin of 6.0dB when you start to go below 6.0dB then you need to start worrying.

0 Ratings
Highlighted
Aspiring Expert
1,525 Views
Message 5 of 8

Re: Noise Margin and Max Data Rate

Hi my SNRM regularly drops below 6db on download usually between 5.3 and 6.1 upload usually sits around 6.0 at the moment 6.4 which is good for me, had a PCP event about a week ago and it dropped my speed from 68 meg to the current 56 meg but left things alone and hope DLM to increase max obtainable rate, but just wondering if there is something wrong with my connection with the low SNRM margins ?
Any help appreciated

1. Product name: BT Home Hub
2. Serial number: +068343+NQ33645431
3. Firmware version: Software version 4.7.5.1.83.8.173.1.6 (Type A) Last updated 24/12/13
4. Board version: BT Hub 5A
5. VDSL uptime: 7 days, 04:25:33
6. Data rate: 20000 / 56748
7. Maximum data rate: 20906 / 66587
8. Noise margin: 6.4 / 5.4
9. Line attenuation: 0.0 / 17.0
10. Signal attenuation: 0.0 / 17.0
0 Ratings
Highlighted
Aspiring Expert
1,506 Views
Message 6 of 8

Re: Noise Margin and Max Data Rate

Any ideas anyone ?
0 Ratings
Highlighted
Expert
1,487 Views
Message 7 of 8

Re: Noise Margin and Max Data Rate


@Jaseb41 wrote:
Any ideas anyone ?

To me it looks like your download SNRM is having a battle with noise/interference and your probably seeing your down SNRM decreasing in the evenings and when the DLM starts seeing your SNRM going below a certain level you may get a lower re-sync which should increase the SNRM.

It's hard to find and cure noise/interference as some of that may be Radio Frequency Interference from broadcasting stations on AM which effect the Mid tones from 1680 to 1720, and there is also something call crosstalk when new customers get connected to your Cabinet.

 

If you think there is a fault then call it in.

Highlighted
Aspiring Expert
1,464 Views
Message 8 of 8

Re: Noise Margin and Max Data Rate

Thanks newtronstar it's sounds just like what could be happening I will keep an eye on it any more problems will phone bt cheers !
0 Ratings