Craig Birkmaier wrote: > Then again, the average MVPD customer is consuming at least this much > bandwidth today, albeit via a very broad band infrastructure (500 MHz > of the same stuff to every home). > > Looks more like a change in topology than a significant difference in > bandwidth... And topology changes are cheap? MVPDs, and this includes Verizon FiOS, use passive optical networks or passive coax networks, to reach individual homes. This plant is used to support TV broadcast channels, Internet unicast, and telephone unicast. A headend transmits downstream, and that signal is passively split through a series of optical splitters. All upstream traffic is also aggregated, and must reach the headend before going anywhere else. There are no active components in the middle of that cable plant. This is nothing like a typical switched Ethernet network you might see in an office complex. For the Internet service, GPONs or GEPONs are the typical fast plant these days, since 2008. That's an aggregate 1 Gb/s downstream Internet service, passively split to reach all the homes in a neighborhood. This Internet service would typically use one of the wavelengths of the PON. So, if 10 homes are each receiving 100 Mb/s of unicast traffic, that saturates the plant. When the ISPs install the GPON, even if they advertize 100 Mb/s service to high-paying households, they are banking on the fact that very few households will use that 100 Mb/s simultaneously, and certainly not continuously. This has always been the assumption in Internet provisioning. Anytime now, 10GPONs will start being deployed. So now 100 homes would saturate the plant, if each were downloading at 100 Mb/s at the same time. And that's the fastest PON just starting to become available today. So, either you create a denser topology, which is not free, or you increase the speed of each PON, which is also not free. It always involves labor on site. Of course the ISPs are going to be reluctant to do this, until it becomes inevitable. Just because the average joe doesn't witness all this work going on, or doesn't know that it costs money, doesn't mean these considerations don't matter. Bottom line is, just because a fiber may be capable of very high bit rates, that doesn't mean that the network behind that spigot will support top speed to every household at the same time. Bert ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.