Problem is two fold dkos1127:
1) Upstream power levels for most customers on 'edges' of service need to be improved (i.e. decreased) so they have stable service. This means removing as many in-line amplifiers and splitters as possible. All that stuff does is consume extra power and create problems. By building nodes closer we lessen cable length, therefore have less houses to reach, less signal loss due to splitters and no amplifiers are necessary. Also the closer you build the easier the future upgrade path is for FTTH.
2) Node capacity. In an 8x4 setup you are sharing 304/108Mbps with x homes. It could be 400 homes, 2000, or 30. It all depends how much the provider wants to oversell.
We know exactly what channels Rogers uses for their 8x4 304/108Mbps setup, at least in Ontario:
Downstream (MHz): 591, 597, 603, 609, 615, 621, 633, 639
Upstream (MHz): 22.1, 25.3, 31.3, 38.6
By turning off analog TV, Rogers will simply have the choice to use some of those channels for internet in the future. They cannot in the short-term because there is no hardware on the market worth buying to take advantage of this new "free bandwidth". The 24x8 960/216Mbps Puma6 chipset announced recently is only being trialed in South Korea later this year.
For a 24x8 setup, Rogers needs to allocate another 16 downstream channels to the existing 8 for 24 total. These 24 downstream channels could then be used in two ways. Either in 1 24 channel set to deliver 960Mbps downstream or split into 3 8 channel sets of 320Mbps each. So a customers modem will tune 8 downstream channels of those 24 available. By doing this providers can maintain the same quality of service for customers and achieve triple downstream capacity on 1 node instead of installing three new ones (and obviously realize 75% savings).
Now since this whole thread is about upstream its worth noting there is precious little spectrum for upstream in the current DOCSIS standard. Upstream is limit to 8 channels. For upstream, Rogers could allocate another 4 to the 4 that exist now for 8 total and have 2 4 channel sets. The most we will ever see is 216Mbps upstream per node. Because of this cable is dead in the water for most business users, remote workers and others that require fast upload bandwidth.
I made this diagram to illustrate. Each home icon represents 50 homes: http://i.imgur.com/i5JrQ.png
Basically Rogers needs to reconfigure their topology to look like the bottom. They started that in 2010. Who knows what their progress is, haven't seen any progress disclosed. The last number I got was 350 subs per node in 2008. My guess is most Ontario and Eastern Canada cities are years away from a full upgrade. Bell has been bringing fiber less than 1KM close to the customer starting with ADSL2 remotes back in 2004, Fibe may not be available in the boonies yet but no matter what Bell got a 6 year head start.
