Canadian cable carriers seem to have all told the CRTC they can only carry 42mhz in the upstream because their amplifiers and nodes only amplify that narrow band in the upstream direction. Is/was 42mhz common across north america ? In a typical installation, how much of the 42mhz is actually usable for upstream data ? (aka: how many 6mhz chunks are taken for TV STBs, Telephony and whatever other upstream channels. I think I heard that one 6mhz chunk is used for one the low numbered TV analogue channels. (although cablecos are slowly widthdrawing analogue TV now). Am trying to figure out realistic bandwidth that a cableco with 42mhz limits for upstream will get on 3.1. Also, have cablecos with such limits for upstream begun to upgrade the cable plant to increase the upstream bandwidth ? Canadian cablecos have told the regulator it would be prohibitively expensive to do so, but incumbents tend to exagerate these things when it is convenient. (they can then claim higher costs/congestion/need for node splits which increates regulated wholesale rates). And would it be correct that in RFoG deployment, the 42mhz limit disapears as the customer equipment talks directly tothe CMTS over fibre all the way ?