Originally Posted by NashGuy
A given wavelength of spectrum can support only so much bandwidth. Bandwidth demands will only ever increase. At some point, some company, with the support of the FCC -- whether the current 5G operators or others -- will seek to use much or all of the UHF TV spectrum to instead carry IP data.
A given wavelength of spectrum can only carry so much data per site
. What has already happened, and will continue to happen, is the densification of sites. Gone are the days of Verizon's 55,000 site network that has the most coverage from the fewest sites stretched to the absolute maximum using 850mhz CDMA. As sites densify, the low-band spectrum becomes less useful, as the range is simply not needed, and the mid- to high-band spectrum becomes more useful, as more area is covered by the relatively limited range of higher frequency spectrum by the increasing number of smaller and smaller sites. At some point, it reaches and equilibrium where the mmWave isn't even heavily utilized outside of a few specific use cases, since the density of sites required for it vastly increase the capacity on the lower frequencies. I just don't see the UHF TV spectrum fitting into this model. Even 700/850mhz spectrum is tough to control on small sites, as they have to crank the power way, way down to not interfere with adjacent sites. In the areas where it is valuable, i.e. the middle of nowhere, it can simply be done as TVWS, which doesn't kick TV stations off, but just uses whatever is available wherever it is available.
You know quite a lot about the technicals of the industry but, as is often the case, your knowledge of the intricacies of the bark on each tree keeps you from seeing the forest. Look at the big picture: linear channel TV is dying, the national networks will increasingly not need local OTA stations for distributing their national high-value content, all forms of interpersonal and mass communication are moving to the internet, and our bandwidth needs for all sorts of IP devices unhindered by wires will only continue to grow. Yes, you can think up technical reasons why, at least in the near-term, it doesn't *yet* make sense to refarm that TV spectrum into 5G (or perhaps some other standard of wireless broadband, which is all TV white space internet is). But in the longer term, it WILL make sense because there will be greater public need for more wireless IP bandwidth than there is need for ATSC 1.0 or 3.0 TV.
The "need" for more spectrum is arbitrary. Providers want to have more spectrum as there is this arms race now for spectrum that Verizon seems to have missed out on, forcing them to densify. There is no particular reason why they need 150mhz or 500mhz or 800mhz, other than that a carrier with less spectrum has to build denser sites. There does become a point where you can only go so dense, and find so many places to put them, but the basic principle is such that you could run a network off of 10mhz of spectrum if you had a site every few power poles. That's just not practical if your competitors have 100mhz of spectrum and only need a site every 5 blocks.
That UHF TV bandwidth is not really very good for wireless service in metro areas. The only place it's actually good for wireless service is in very rural areas, which can do TVWS. In the metro areas, the network will be so densified by the point that some of the TV spectrum that might be available in the UHF spectrum would be a drop in the bucket. With a heavily densified network, carriers will have huge swaths of CBRS, C-Band, and mmWave, so 50 or 100mhz of UHF that requires massive antennas and doesn't even work that well with handheld devices isn't going to be very valuable.
I absolutely agree that the big network model is dying, but I don't think linear OTA TV is going to die anytime in the next couple of decades. OTA TV has an inherent advantage in being free, and it will continue to grind out an existence one way or another. We still have AM radio, we still have FM radio, and we're still going to have OTA TV. It's probably going to look a lot more like The CW or Ion than the big four of 5 or 10 years ago, but it will still be kicking around in one form or another. There is also a big market for foreign language programming, so that could pop up to backfill it as well. If smaller TV markets abandon OTA broadcasting, then that spectrum would just go into the pool for TVWS uses, probably by small WISPs or whomever. Maybe some TVWS use would even be allowed by the big cellular carriers, but that could happen while that same spectrum is still in use in major metro markets where it is far less valuable to wireless operators, and the higher frequencies are far more valuable.
A problem that doesn't exist? OK, let's stop for a moment and think about why our government licenses spectrum to OTA TV stations and regulates them the way they do. A BIG part of the rationale is that local TV *serves the public interest*. It provides access to local and national news, it offers emergency warnings and updates for severe weather and disasters. (Note that ATSC 3.0's AWARN system has been one of its biggest selling points to government officials.) It also provides educational content to children (both on PBS and those weekly hours of required content on every other station).
And it does all those things *for free* with no subscription cost to the viewer. Yes, you have to first buy a TV and antenna and then pay for the electricity to run it but you don't have to pay $60 a month for a basic cable TV package nor do you have to pay that much for broadband service as a prerequisite to access that content. It's just there, on our shared airwaves, free for anyone. Unfortunately, though, this free TV set-up -- either in the form of ATSC 1.0 or 3.0 -- requires that our national wireless spectrum and the entire physical distribution chain (towers, cells, etc.) be segregated into two separate systems: cellular (4G/5G) and OTA TV (ATSC 1.0/3.0). As everything moves to IP, we should be asking ourselves "Why are we doing it this way? Why have these two separate systems?"
The two systems do two totally different things. 4G networks today typically cover <5 miles per tower, while ATSC-8VSB covers about 70 miles if you are up high. ATSC 3.0 SFNs can cover even more area with a typical setup of 2-4 towers throughout a market. Why would they try to re-invent the wheel to make a 5G broadcast system that's not even going to cover everyone who can get the OTA signal? It just doesn't make a whole lot of sense. Somehow TV stations are going to convince wireless carriers to pay a ton of money for spectrum that they don't even want, and then provide the TV stations with free distribution for their content, all the while having to significantly improve their wireless networks to get close to the coverage that the ATSC networks used to get on their own. It just doesn't make sense. I think RF36 is going to remain the upper edge of the TV broadcasting space for decades. I'm still 50/50 on whether ATSC 3.0 ends up working, or if we just end up with both for a long time, or partial conversions in some markets. I highly doubt ATSC 1.0 is going anywhere anytime soon.
Perhaps you're imagining a future scenario in which a 90-year-old Pres. Sanders has given "free" socialized broadband service to every American? In which case, yes, you're absolutely right that there would be no need to figure out some new way to distribute local TV, news, educational content, and breaking alerts to virtually every American, regardless of how poor they are, since they could just stream all that stuff over their free broadband connection. But unless we have some kind of universal free wireless broadband, accessible on every stationary and mobile device that matters (for the purposes of emergency alerts), then I believe there WILL still be a need for some forms of free local mass communications that serve the public interest and which have very low barriers to access (meaning no ongoing subscription fees required).
That system is the existing ATSC system. Or currently cell phones, at least for the emergency alerts, since that's what everyone is paying attention to anyway. Unfortunately, I don't forsee our failed broadband policy getting fixed anytime soon. It's one of many policy failures, including many other parts of our infrastructure, and I think piecemeal solutions will chip away at it, but it won't really get solved anytime soon. I don't know what will happen to the ILECs who have refused to upgrade to fiber, or smaller ones that can't afford the initial cost (even though it's very profitable over time), as copper is rapidly becoming a big money-loser as massive maintenance costs swamp the moderate revenues that it still bring in.
But, sure, the US will still be relying on ATSC 1.0/3.0 by 2030 for our free OTA TV while Europe and China have moved on to broadcast-over-5G...
We will definitely still be relying on ATSC in 2030. I think we will be in 2040 as well. We have a totally different system and model than they do, and 5G TV broadcasting just doesn't make any sense in the first place. I'm not putting too much hope in better broadband, as most areas have cable monopolies that have little incentive to do more than the bare minimum to keep vastly overcharging subscribers.
I'm still not sure about ATSC 3.0. It might work, it might fail. The economic incentives aren't aligned very well for broadcasters, but some could by eyeing a ton of sub-channels to grind out revenue. We'll see I guess.