View Full Version : Modem Power Levels across all platforms
This is the latest modem power levels across all platforms.
Downstream power levels.
QAM 256 all platforms
Too Low -20 to -7 ~ Accept -6 to -4 ~ Optimal -3 to 7 ~ Accept 8 to 10 ~ Too high 11 to 20
QAM 64 Knowsley
Too low -20 to -11 ~ Accept -10 to -8 ~ Optimal -7 to 3 ~ Accept 4 to 6 ~ Too high 7 to 20
QAM 64 Langley & Bromley
Too low -20 to -14 ~ Accept -13 to -11 ~ Optimal -10 to 0 ~ Accept 1 to 3 ~ Too high 4 to 20
Upstream power levels QPSK & QAM 16 All platforms
Too low 8 to 30 ~ Accept 31 to 39 ~ Optimal 40 to 50 ~ Accept 51 to 54 ~ Too high 55 to 61 ( 58.2 max on Motorola BSR's )
Downstream SNR
QAM 256 All Platforms
Too low 10 to 31 ~ Accept 32 to 34 ~ Optimal 35 to 45
QAM 64 All Platforms
Too low 10 to 28 ~ Accept 32 to 34 ~ Optimal 35 to 45
The formatting of this is confusing; there's just a stream of numbers under each platform
joglynne
03-06-2011, 19:22
Cheers Masque, I was starting to think I was seeing things as my readings seemed to be very high even though I have been getting more consistent speeds. Is it just me being thick or have the levels changed?
So basically downstreams now -6 to +8 and upstream 30 to 54
---------- Post added at 19:26 ---------- Previous post was at 19:24 ----------
I've seen loads of modems within this spec working fine
So basically downstreams now -6 to +8 and upstream 30 to 54
---------- Post added at 19:26 ---------- Previous post was at 19:24 ----------
I've seen loads of modems within this spec working fine
This is the ones we use but obviously not every modem works in the same way.
I hope that my layout is clearer now after some tweaking.
---------- Post added at 19:29 ---------- Previous post was at 19:28 ----------
Cheers Masque, I was starting to think I was seeing things as my readings seemed to be very high even though I have been getting more consistent speeds. Is it just me being thick or have the levels changed?
The specs have changed so I posted the above thread, can everyone read it ok.
joglynne
03-06-2011, 19:32
I understood it the first time but it is easier to follow now. The colours look very flash. :D
Much better thankyou :)
Any reason why the power levels have changed; is that whats causing the nation-wide slowdown or completely unrelated?
pip08456
03-06-2011, 19:38
Now that should be made into a sticky!
I also note there is no mention of 11dBmv being acceptable as posited before!:D:D:D
Much better thankyou :)
Any reason why the power levels have changed; is that whats causing the nation-wide slowdown or completely unrelated?
I know the first attempt was a disaster.:dunce:
No these have been in place for months and I have just got around to posting them on here.
---------- Post added at 19:39 ---------- Previous post was at 19:38 ----------
Now that should be made into a sticky!
I also note there is no mention of 11dBmv being acceptable as posited before!:D:D:D
Up to 11 hence we go to 10 then start from 11.:D
pip08456
03-06-2011, 19:40
Hairsplitter!
On hairsplitting you may wish to put a space between SNR and 256 QAM.
Hairsplitter!
I only post them not set them.:D
Too. As in: "My superhub, bless the saintly hub and all who fail in her, reboots and loses wifi range too often"
To. As in: "My superhub, has been confined to the bin"
Two. As in: "I now have two Virgin devices"
Too
:confused::confused::confused:;)
---------- Post added at 19:44 ---------- Previous post was at 19:43 ----------
Hairsplitter!
On hairsplitting you may wish to put a space between SNR and 256 QAM.
I had noticed but thank you.:)
kwikbreaks
03-06-2011, 19:53
Too. As in: "My superhub, bless the saintly hub and all who fail in her, reboots and loses wifi range too often"
To. As in: "My superhub, has been confined to the bin"
Two. As in: "I now have two Virgin devices"
Too subtle obviously.
My power levels are -11 and snr about 30 and i don't seem to have any issues at the moment.
I'm on the old Cambridge cable network if that makes a difference?
craigj2k12
03-06-2011, 19:57
"to low" should be "too low" and "to high" should be "too high" - typical scouser!
when there is a range of values like "51 -54" it looks like "negative 54" instead of "51 to 54" like "51 - 54"
when those changes are made this should be a sticky ;) nice one Masque
Too subtle obviously.
Not when he had only posted the word "Too" but has now increased the post.
craigj2k12
03-06-2011, 20:05
"to low" should be "too low" and "to high" should be "too high" - typical scouser!
when there is a range of values like "51 -54" it looks like "negative 54" instead of "51 to 54" like "51 - 54"
when those changes are made this should be a sticky ;) nice one Masque
changes made :D looks very good, i hope it will be stickied
thanks again masque
pip08456
03-06-2011, 20:07
Too. As in: "My superhub, bless the saintly hub and all who fail in her, reboots and loses wifi range too often"
To. As in: "My superhub, has been confined to the bin"
Two. As in: "I now have two Virgin devices"
Classic!!! Wrong grammar!
Go to the bottom of the class!
If you wish to be a grammar Nazi at least be right!
craigj2k12
03-06-2011, 20:11
Classic!!! Wrong grammar!
Go to the bottom of the class!
If you wish to be a grammar Nazi at least be right!
too as in: my superhub was rubbish too
to as in: i put my superhub in to the bin
two as in: my superhub was a number two
pip08456
03-06-2011, 20:15
Or to put it simpler, you could say "I had a s****hub and it was rubbish for me and went to put it in the bin but decided to give it to a mate, only to find he had one too and would've ended up with two of them!:D:D:D:D:D
craigj2k12
03-06-2011, 20:20
i used to have a superhub but the wireless range was only two metres and getting further away from it the speeds decreased too. As i got further away, I was only able to get two meg out of it, and after two phone calls, I too was able to get a VMNG300, this allows me to connect my own router to it and I can now get more than two meg, this is when i am more than two metres away too!
pip08456
03-06-2011, 20:27
I think Skie has been chastised enough about his/her's incorrect use of grammar.
Masque thanks for this and the tweaks you've done!:D
I still say it should now be a sticky though most would ignore it!
If i wanted to correct my -11 power levels for downsteam and increase my SNR from 30 to 33 and i wanted to do it myself, what would i need to buy, is it an attenuator or an equaliser and if so which value to bring up to acceptable levels.
I'd rather do this than take half a day off work waiting for a tech to arrive.
kwikbreaks
03-06-2011, 20:56
I still say it should now be a sticky though most would ignore it!
Minus all the snide comments it would indeed make a good sticky. Too bad that many would fail to read it :)
---------- Post added at 20:56 ---------- Previous post was at 20:54 ----------
If i wanted to correct my -11 power levels for downsteam and increase my SNR from 30 to 33 and i wanted to do it myself, what would i need to buy, is it an attenuator or an equaliser and if so which value to bring up to acceptable levels.
I'd rather do this than take half a day off work waiting for a tech to arrive.
Attenuators reduce power and yours needs increasing so needs a VM bod to alter your tap in the cabinet.
pip08456
03-06-2011, 21:01
If i wanted to correct my -11 power levels for downsteam and increase my SNR from 30 to 33 and i wanted to do it myself, what would i need to buy, is it an attenuator or an equaliser and if so which value to bring up to acceptable levels.
I'd rather do this than take half a day off work waiting for a tech to arrive.
A forward path attenuator which is the most used will only reduce your downstream power levels. If there is one fitted then remove it to see what they are.
You obviously do not understand what SNR is but just see it as a figure.
How do you intend to adjust the Signal to Noise ratio for your connection to the CMTS? Ooops (Cable to Modem Termination System).
craigj2k12
03-06-2011, 21:14
A forward path attenuator which is the most used will only reduce your downstream power levels. If there is one fitted then remove it to see what they are.
You obviously do not understand what SNR is but just see it as a figure.
How do you intend to adjust the Signal to Noise ratio for your connection to the CMTS? Ooops (Cable to Modem Termination System).
his name is harry potter and a peice of metal attached to his modem will solve all his problems
Obviously i didn't understand that is why i was asking. Thanks for the detailed reply Pip and Kwikbreaks, so a tech it is then, i will mention it if i get a Tivo fitted.
pip08456
03-06-2011, 21:24
Obviously i didn't understand that is why i was asking. Thanks for the detailed reply Pip and Kwikbreaks, so a tech it is then, i will mention it if i get a Tivo fitted.
I'd mention it now if I were you!
I'd mention it now if I were you!
It has been those levels for the last 5-10 years and i don't have any speed issues yet. :)
pip08456
03-06-2011, 21:27
Merely my opinion, not cast in stone!:D
Merely my opinion, not cast in stone!:D
True and it may improve the my broadband monitor readings which have alot of yellow on it! ;) or maybe that is the superhubs fault!
Sephiroth
03-06-2011, 23:10
I'd like to understand this Knowsley/Langley thing, please.
It strikes me that the difference Masque shows can be explained in terms of legacy CMTS outputs and different amplifier/Gain settings in the cabinets and streets. i.e. Historically, Knowsley is set up one way, Langley another.
Yet, why would a SH or VMNG 300, for example, be stressed if the 64QAM DS in the Langley area is running at 5 dBmv?
Other than that, very nice, Masque (although -20 is outside DOCSIS 3 spec AFAIK - I'm happy to be corrected on that).
I'd like to understand this Knowsley/Langley thing, please.
It strikes me that the difference Masque shows can be explained in terms of legacy CMTS outputs and different amplifier/Gain settings in the cabinets and streets. i.e. Historically, Knowsley is set up one way, Langley another.
Yet, why would a SH or VMNG 300, for example, be stressed if the 64QAM DS in the Langley area is running at 5 dBmv?
Other than that, very nice, Masque (although -20 is outside DOCSIS 3 spec AFAIK - I'm happy to be corrected on that).
Nothing to do with me Seph just the power level range that we are supposed to use, but most agents would be well aware of what will happen once the levels start to go out of the acceptable normal range.
Knowsley is Telewest and Langley is NTL and they used to use different kit and advised completely different power level ranges.
Classic!!! Wrong grammar!
Go to the bottom of the class!
If you wish to be a grammar Nazi at least be right!
lol
My power levels are -11 and snr about 30 and i don't seem to have any issues at the moment.
I'm on the old Cambridge cable network if that makes a difference?
Since when has it been old?
lol
Funny how he was wrong though. "Too often" is correct, not "to often". :angel:
I know my downstream power is a little high - but can never remember which platform I'm on, so it may not be. It may be useful to link to a "which platform am I on?" post.
Sephiroth
04-06-2011, 12:58
I know my downstream power is a little high - but can never remember which platform I'm on, so it may not be. It may be useful to link to a "which platform am I on?" post.
We can usually tell from the Host details in Virginmedia's Mytools section
Too low 10 to 28 ~ Accept 32 to 34 ~ Optimal 32 to 45
Should that not be Optimal 35 to 45?
Too low 10 to 28 ~ Accept 32 to 34 ~ Optimal 32 to 45
Should that not be Optimal 35 to 45?
Yes I did not spot that so thank you.
Failswitch
12-06-2011, 18:29
+1 for OP to be stickied. The last post from the current power level stickied thread is over 2 years old!
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