Superhub : Superhub 2 Power levels

[TROTER]

After getting my hub changed from SH1, I believe my power levels to be a little low?

Power Level (dBmV) -2.88 -3.51 -3.05 -3.66 -3.90 -4.14 -4.16 -4.40
RxMER (dB) 32.87 32.87 32.77 32.58 32.07 31.84 31.84 31.62

I am right that the parameters are between -3 and +7 ? (Old Telewest)

The technician did change something at the cab, power levels for SH1 were always around +1. I am being told that there is no problem with power levels can anyone confirm?

[qasdfdsaq]

Technically, your power levels are just about OK.

It's the SNR that's worrying, 31-32 is way below optimal.

[TROTER]

Originally Posted by qasdfdsaq

Technically, your power levels are just about OK.

It's the SNR that's worrying, 31-32 is way below optimal.

Thanks for the quick reply, then why did the tech support not pick up on this?

---------- Post added at 17:52 ---------- Previous post was at 17:34 ----------

Virgin has just told me that there is no problem with my power levels or SNR? He said that they have a traffic light system which shows my SNR and power levels all in the green...

[ianch99]

Originally Posted by TROTER

Thanks for the quick reply, then why did the tech support not pick up on this?

---------- Post added at 17:52 ---------- Previous post was at 17:34 ----------

Virgin has just told me that there is no problem with my power levels or SNR? He said that they have a traffic light system which shows my SNR and power levels all in the green...

Seph's power level & SNR primer recommends 33 dB as a minimum:

So at minimum we’d be wanting to see better than 33 dB at 256QAM

[v0id]

Is it working?

Yes: Leave it alone
No: Contact tech support

[ianch99]

Originally Posted by v0id

Is it working?

Yes: Leave it alone
No: Contact tech support

Define "working"?

[General Maximus]

no downtime/uninterrupted service and the op can achieve headline speed

[ianch99]

Originally Posted by General Maximus

no downtime/uninterrupted service and the op can achieve headline speed

and is this possible with downstream SNR around 31/32 dB? Maybe the OP can say whether he getting no downtime/uninterrupted service and can achieve headline speeds? If yes then no worries ..

[Sephiroth]

The all important thing is the SNR. The OP's SNR is unacceptable and will be czusing corrupted data.

The SH1 would have been reporting around 2 dB higher SNR. If that was giving trouble and a SH2 was fitted, you can see that the problem lies towards the VM end outside the modem. Anything from loosely screwed in cables at the home to a noisy amplifier, noise in the network, breakdown in the wall box splitter etc.

[TROTER]

Just got off the phone after speaking to a senior technician at VM, again I was assured there were no issues with noise on my line. He told me that SNR would only become a concern on my part of the network at around 20dB.

Power Level (dBmV)-2.41 -3.13 -2.47 -3.07 -3.37 -3.59 -3.58 -3.83
RxMER (dB)33.72 33.60 33.72 33.49 32.87 32.77 32.77 32.50

[qasdfdsaq]

Lol. With a SNR of 20dB there wouldn't be a network to connect to

[jb66]

The new signal spec virgin go by is -6 to +8. Snr is a minimum of 34, upstream maximum of 51.

[TROTER]

I have no down time on my network, and can archive full speeds outside of congested times. Latency doubles or worse at peak times of the day which stops me wanting to game, I just want the best possible experience I can achieve.

I have had a contract with cable for 14 years and have just recently renewed, but with BT fibre coming to my area soon this could be the last year.

Power Level (dBmV) -0.96 -1.72 -0.96 -1.58 -1.92 -2.07 -2.13 -2.38
RxMER (dB) 36.61 36.61 36.61 36.17 35.97 35.60 35.60 35.42

Here are my latest readings, seem to improved a little later in the day. Do not know if this is due to temperature or utilization? If it is temperature then I expect these figures to degrade throughout the upcoming summer.

[Sephiroth]

Originally Posted by TROTER

Just got off the phone after speaking to a senior technician at VM, again I was assured there were no issues with noise on my line. He told me that SNR would only become a concern on my part of the network at around 20dB.

Power Level (dBmV)-2.41 -3.13 -2.47 -3.07 -3.37 -3.59 -3.58 -3.83
RxMER (dB)33.72 33.60 33.72 33.49 32.87 32.77 32.77 32.50

The ST should have known better. 20 dB is likely to be the minimum acceptable noise value of the UPSTREAM at the CMTS (Though AFAIK that should be 22 dB according to the DOCSIS 3 spec.).

---------- Post added at 23:45 ---------- Previous post was at 23:42 ----------

Originally Posted by TROTER

I have no down time on my network, and can archive full speeds outside of congested times. Latency doubles or worse at peak times of the day which stops me wanting to game, I just want the best possible experience I can achieve.

I have had a contract with cable for 14 years and have just recently renewed, but with BT fibre coming to my area soon this could be the last year.

Power Level (dBmV) -0.96 -1.72 -0.96 -1.58 -1.92 -2.07 -2.13 -2.38
RxMER (dB) 36.61 36.61 36.61 36.17 35.97 35.60 35.60 35.42

Here are my latest readings, seem to improved a little later in the day. Do not know if this is due to temperature or utilization? If it is temperature then I expect these figures to degrade throughout the upcoming summer.

As temperature rises, coax expands and offers higher resistance (at its simplest). So downstream power would fall. SNR is not significantly affected by temperature.

So I reckon they've fixed it or a transient went away.

[TROTER]

The senior technician from virgin that I spoken to did seem to know his onions, even as far as to know what make of router I had behind my SH2? Thanks for all your input people.