on 30-11-2023 19:50
Hi had some work on my local network done today as it says it was doing upgrade work to improve the services,
But after being down for half the day when the hub came back online I saw the power levels are way out if sync now. The downstream before was between 0 and 3dbmv and the upstream dbmv was about 38 dmbv, now the downstream is +10 dbmv and the upstream is now around 34dbmv, do I need an engineer to fix it? I have a 6db forward path attenuater fitted at back of hub which i could change to a 10db forward path attenuator to bring down the downstream power levels but its the upstream I'm concerned about as its only 34dbmv?
Have I a problem now?
Password | Show |
1 | 138750000 | 9.8 | 38 | 256 qam | 1 |
2 | 146750000 | 9.5 | 38 | 256 qam | 2 |
3 | 154750000 | 9.5 | 38 | 256 qam | 3 |
4 | 162750000 | 9.5 | 38 | 256 qam | 4 |
5 | 170750000 | 9.6 | 38 | 256 qam | 5 |
6 | 178750000 | 9.5 | 38 | 256 qam | 6 |
7 | 186750000 | 9.5 | 38 | 256 qam | 7 |
8 | 194750000 | 9.6 | 38 | 256 qam | 8 |
9 | 202750000 | 9.6 | 38 | 256 qam | 9 |
10 | 210750000 | 9.5 | 38 | 256 qam | 10 |
11 | 218750000 | 9.6 | 38 | 256 qam | 11 |
12 | 226750000 | 9.6 | 38 | 256 qam | 12 |
13 | 234750000 | 9.8 | 38 | 256 qam | 13 |
14 | 242750000 | 9.6 | 38 | 256 qam | 14 |
15 | 250750000 | 9.8 | 38 | 256 qam | 15 |
16 | 258750000 | 9.8 | 38 | 256 qam | 16 |
17 | 266750000 | 10 | 38 | 256 qam | 17 |
18 | 274750000 | 9.8 | 38 | 256 qam | 18 |
19 | 282750000 | 9.8 | 38 | 256 qam | 19 |
20 | 290750000 | 9.8 | 38 | 256 qam | 20 |
21 | 298750000 | 10 | 38 | 256 qam | 21 |
22 | 306750000 | 10 | 38 | 256 qam | 22 |
23 | 314750000 | 10 | 38 | 256 qam | 23 |
24 | 322750000 | 10.1 | 38 | 256 qam | 24 |
1 | Locked | 38.9 | 6 | 0 |
2 | Locked | 38.6 | 6 | 0 |
3 | Locked | 38.6 | 6 | 0 |
4 | Locked | 38.9 | 5 | 0 |
5 | Locked | 38.6 | 7 | 0 |
6 | Locked | 38.6 | 5 | 0 |
7 | Locked | 38.6 | 18 | 0 |
8 | Locked | 38.9 | 15 | 0 |
9 | Locked | 38.9 | 5 | 0 |
10 | Locked | 38.9 | 6 | 0 |
11 | Locked | 38.6 | 4 | 0 |
12 | Locked | 38.9 | 7 | 0 |
13 | Locked | 38.9 | 5 | 0 |
14 | Locked | 38.9 | 5 | 0 |
15 | Locked | 38.9 | 4 | 0 |
16 | Locked | 38.6 | 5 | 0 |
17 | Locked | 38.6 | 6 | 0 |
18 | Locked | 38.6 | 4 | 0 |
19 | Locked | 38.9 | 5 | 0 |
20 | Locked | 38.9 | 6 | 0 |
21 | Locked | 38.6 | 6 | 0 |
22 | Locked | 38.9 | 5 | 0 |
23 | Locked | 38.9 | 5 | 0 |
24 | Locked | 38.9 | 5 | 0 |
on 13-04-2024 14:26
Password | Show |
1 | 23599975 | 34.5 | 5120 | 64 qam | 5 |
2 | 36600000 | 34.8 | 5120 | 64 qam | 3 |
3 | 30100000 | 34.5 | 5120 | 64 qam | 4 |
4 | 43100015 | 34.8 | 5120 | 64 qam | 2 |
5 | 49600000 | 35.3 | 5120 | 64 qam | 1 |
1 | ATDMA | 0 | 0 | 2 | 0 |
2 | ATDMA | 0 | 0 | 1 | 0 |
3 | ATDMA | 0 | 0 | 4 | 0 |
4 | ATDMA | 0 | 0 | 2 | 0 |
5 | ATDMA | 0 | 0 | 0 | 0 |
on 13-04-2024 14:27
Hi I need to change appointment but won't let me do it, it doesn't work?
on 13-04-2024 14:29
Perhaps you could look int the drop box outside your property to see if it's waterlogged. If s, that's you upstream shot till it dries out and then electrolytic micro-reflections can occur.
Also I recommend checking with the neighbours. If they have the same problem, then it could be water getting into the nearby cabinet.
13-04-2024 18:23 - edited 13-04-2024 18:24
15 dBmV can be fine on downstream mostly the your upstream is the problem the Modulation can change so fast that BQM might not show a drop or spike even when T# show
on 13-04-2024 18:58
Hi thanks for reply seph, no water in omnibox that I can see, most of my neighbours aren't on vm but I will try and find one and ask them.
on 13-04-2024 19:00
Hi legacy1, Oh I didn't know that the downstream power levels can go up to 15dbmv and still be OK, interesting..
on 13-04-2024 19:01
Not the Omnibox, but the drop box in the street outside your property. Btw, thx for your kind words earlier.
on 13-04-2024 19:13
Hi seph are u talking about the little plastic square box cover on the ground?
13-04-2024 19:19 - edited 13-04-2024 19:21
It looks as though whatever work they did has been left with the network not being properly lined up.
Your upstream transmit is too low. I suspect that's the case for more people in your area.
Wherever the planned work was done they either need to lower the return path gain or add attenuation to get your modems transmitting at a higher power and get them higher above the noise floor.
This needs a network engineer. The planned works don't seem to have quite been done right, your upstream transmit seems 6 dBmV lower than it was and unless the cable plant is insanely clean 64QAM is challenging.
Your actual stats in terms of modulation and T3s fit with this. The lower frequencies are naturally more noisy so the idea that there's no real obnoxious source of noise just upstream transmit is too low to give a high enough noise margin over the regular noise floor fits.
on 13-04-2024 19:20
Yes I am. The one in the ground. Btw, 15dBmv is within DOCSIS spec but this power level is at the mercy of the components and in less robust hubs, the extra power also amplifies noise.