Quote:
Originally Posted by Sephiroth
Also I'm puzzled as to why an attenuator would need to be fitted for upload power? BBings will correct me quickly where I might be wrong, but upstream power is determined by the CMTS based in its SNR estimate. If an upstream attenuator is fitted, I'd expect the CMTS to continue to raise the upstream power to combat whatever noise is on the circuit and if none (now) to overcome the attenuator.
|
SNR no, CMTS tells modem to raise power to reach target received power. SNR only becomes an issue when it's so bad CMTS doesn't 'hear' modem, then it'll tell it to raise power as it assumes Tx power is too low.
Attenuator probably not for upstream.
I'll pass on commenting on the below in full beyond that the CMTS doesn't react to SNR conditions downstream, it has no visibility of unless asked to poll modems and won't change downstream modulation in response to modems in strife.