Quote:
Originally Posted by Sephiroth
It's a good thing up to a point where noise injection power sort of swamps modem output power.
Fwiw, my 20 meg modem for years ran on 29 dBmv without problem; the street amplifier is < 80m cable distance away.
The upstream power level is commanded by the CMTS at the VM end. It commands the minumum power necessary (+ a small margi, I believe) for the CMTS to be able to make sense of what it is receiving from the modem. That can vary every 30 seconds or so depending on line conditions.
Other than that, it's what JB says; more attenuation at the street cabinet will raise the upstream power output by the same amount.
|
In your opinion do you think all my levels are ok? I once suffered from a really low downstream power level but since a repull all my levels are like this and this is the best downstream i can get as i don't have any forward path attenuators on unless there is outside my property.
Unusually my SNR has increased 1/2 dB and my upstream had dropped 0.5 dB today as it was normally rock solid.
Quote:
Downstream Channels
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power SNR Docsis/EuroDocsis locked
Locked QAM256 55 55616000 Kbits/sec 323000000 Hz -1.1 dBmV 37.0 dB Hybrid
Locked QAM256 49 55616000 Kbits/sec 291000000 Hz 0.0 dBmV 36.2 dB Hybrid
Locked QAM256 50 55616000 Kbits/sec 299000000 Hz -0.2 dBmV 36.5 dB Hybrid
Locked QAM256 53 55616000 Kbits/sec 307000000 Hz 0.0 dBmV 36.8 dB Hybrid
Locked QAM256 54 55616000 Kbits/sec 315000000 Hz -0.8 dBmV 36.5 dB Hybrid
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Upstream Channels
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power
Locked ATDMA 2 20480 Kbits/sec 35800000 Hz 37.3 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
|