|reply to Sanek |
Re: Rogers Upstream Bonding
Although the spec does permit 5-42 MHz, this range is splattered with RF noise from shortwave transmitters of many sorts and RF generated by things like dimmers, fluorescent lamps ... all manner of electical interference. This is why when cable modems fail, they usually fail because of signal levels on the upstream path rather than the downstream The selected range is normally just above 30 MHz being one of the "quieter" parts of the spectrum.
Rogers currently uses 16 QAM on its upstream path to keep noise problems to a minimum. To use higher modulation standards would mean it would be even more sensitive to noise.
Some MSOs with relatively new installations of neighbourhood cable plant can increase to higher QAM depth, but Rogers is a very mixed bag when it comes to cable plant. Some areas are comparatively new, and some are very old. Most MSOs are looking to move to the frequencies above 50MHz because they are quieter once released from TV use.