on 15-02-2011 13:04
I have mentioned this in my other thread here http://community.virginmedia.com/t5/Fibre-optic-br
but it seems my question is being over looked due to the title so appoligies for repeating myself,
Here are my stats, are they to high?
15-02-2011 16:58 - edited 15-02-2011 17:19
The downstream is far too high going by that guide in sticky at top of this section that says :
DOWNSTREAM POWER (Optimal)
Rule of thumb: -3 dBmv to +6 dBmv
The above advice compares with the VM stated optimum values by region (according to implemented infrastructure standards) and modulation:
QAM64 (Knowsley networks) -7 dBmv to +3 dBmv
QAM64 (Langley/Bromley) -10 dBmv to 0 dBmv
QAM256 -3 dBmv to +7 dBmv
An attenuator could fix that unless its a network issue !
16-02-2011 10:15 - edited 16-02-2011 10:28
yeah i did read that post but was unsure if that applied to the super hub as it doesnt look like its been updated in a while, and this is what it says at the beginning
The CMs are advertised with a wider power range than is considered healthy for a stable connection. For example, the Ambit 256 modem is spec'd for downstream in the range -15 to +15 dBmv (slight variations according to 64QAM or 256QAM but these are ignored for the purpose of this article. There are also variations attributable to the local implementation of DOCSIS or EURODOCSIS which employ different channel bandwidth and frequency plans; these variations are also ignored for the puroses of this article.
16-02-2011 10:34 - edited 16-02-2011 10:37
Mine were between 11 & 12, an engineer fited a 6Db attenuator which brought them down to 6.
So yes, yours are definately way to high.
Refer to: POWER LEVELS & SNR: A TECHNICAL PRIMER by Sephiroth
High downstream power amplifies noise (but if the CM is close to the street cabinet, SNR wiill be high and noise will be low). High downstream power also overdrives the CM amplifier, but not all CMs are as sensitive as each other. So this is a moving target.
on 16-02-2011 11:00
Did this improve your general speed over wireless and wired?
Currently get about 24 wired and 12-15 wireless (being in the same room as the router)
on 20-02-2011 14:48
I can see that my colleague Ray has picked up your issue in the other thread. Once you have sent him a PM with the times you're available for an engineer we will arrange this for you.