Cable Forum - View Single Post - General Virgin Media should have matched BT FTTC

qasdfdsaq · 20-10-2012, 12:21

Upstream channels cannot be expanded at the expense of downstream without breaking DOCSIS specs and getting custom built modems/STBs/TIVO receivers modified to use them. That would require replacing a huge amount of end-user equipment, cabling, in-street amplifiers, and cabinets to the extent they may as well build a new network. Unlike VDSL (e.g. BT Infinity) which can arbitrarily use any frequency for upstream or downstream, cable has fixed frequencies for each direction that cannot be changed.

TV doesn't really use any upstream channels so its presence doesn't really change much.

20-10-2012, 12:21	#75
qasdfdsaq cf.mega poster Join Date: Aug 2004 Posts: 11,207	Re: Virgin Media should have matched BT FTTC Upstream channels cannot be expanded at the expense of downstream without breaking DOCSIS specs and getting custom built modems/STBs/TIVO receivers modified to use them. That would require replacing a huge amount of end-user equipment, cabling, in-street amplifiers, and cabinets to the extent they may as well build a new network. Unlike VDSL (e.g. BT Infinity) which can arbitrarily use any frequency for upstream or downstream, cable has fixed frequencies for each direction that cannot be changed. TV doesn't really use any upstream channels so its presence doesn't really change much.