Take off in what way?
- From a marketing standpoint, it's going to be big simply because carriers are investing so much money in it. They're going to tout it as the greatest thing since sliced bread so they can make a return on their investment. With that much money going into marketing, it will probably sell.
- From a technological standpoint, it's kinda nifty. It's nothing revolutionary--there aren't any major technological advancements in it there aren't already available via other specifications--but it's nice to see these technologies adopted in a universal cell standard.
- From a utilitarian standpoint, it's useless for most current applications of cell technology. It's far too high frequency to travel any significant range, and it really can't penetrate solid objects. The higher-frequency, higher-speed version of it is particularly susceptible to these issues. You can get about 40x the range and similar speeds with < $100 Wi-Fi-based stations that rural ISPs are already using. In all but the most optimal conditions, it won't be any faster than 4G.
- It has the potential to increase the availability of high-speed internet in vehicles, especially in the context of public transportation. This opens a lot of doors, especially in densely populated areas, but it's not viable for most fleet tracking due to lack of range and coverage.
- It doesn't really offer much for embedded applications. Neither did 4G, which is why mass-deployed embedded devices typically only use 2G/3G. Speed isn't relevant in that context--range and power usage are much more important.
- It's useful for quick, cheap deployment of internet to houses. In this scenario, your devices won't connect to it directly: instead, you'll have a modem and a home Wi-Fi network, same as before. The advantage is that it obviates the need to have the "cable guy" come to your house, drill holes in walls, and run a bunch of wires; instead, the ISP can just ship you a router that you plug in somewhere along the wall of your house closest to the street. For many ISPs, this is the main selling point and the primary reason they're investing in 5G.
- Initially, we're probably going to see phones that support 5G as a result of marketing hype. There's little practical reason for a phone to support 5G; from such a device, it's going to be roughly the same as 4G, but shorter-range. 5G wasn't really designed for portable devices.
Personally, I hope to see 5G replace open Wi-Fi hotspots. In that context, it's more secure, less prone to privacy issues, prevents implementation of annoying gateway portals that require personal information, and obviates the need for manual selection of and connection to individual networks. This is somewhat unlikely, though--providers could already do this with 4G (or 3G, or 2G), but they don't because it's more expensive, less convenient, and less informative in terms of marketing metrics like browsing history.
To give you a very rough idea of the impact of 5G's most glaring issue, you can picture different wireless internet technologies on a sort of spectrum:
- 3G travels pretty far, but it's also slow. It's also reasonably good at bouncing around and through solid objects.
- 4G is faster than 3G, but it's not so great when it comes to range. The speed differences between 3G and 4G are most apparent when you're close to a cell tower and have a mostly-clear line-of-sight. Once you get farther away, 3G is more reliable and will continue to work where 4G doesn't.
- 2.4 GHz Wi-Fi can be faster and more stable than 4G, but it doesn't travel far at all, especially with portable devices. Although it's possible to get 2.4 GHz Wi-Fi working over long ranges with stationary, perfectly-tuned devices, typically it's only going to work within a small enclosed area, like an apartment or small house. If you're in an older building with solid walls, you might not even be able to achieve that much.
- 5G FR1 is moderately fast. It can travel farther and penetrate solid objects better than 5 GHz Wi-Fi. Like 2.4 GHz Wi-Fi, the range can vary pretty widely, but you shouldn't expect it to go beyond a few hundred meters in most situations. It's enough to get from the street to the inside of your house in most cases, but a single station isn't going to cover a whole block. It's also the slower of the two forms of 5G, at least in theory.
- 5G FR2 is very short range. While it has the potential to travel farther than 5 GHz Wi-Fi with a clear line of sight due to increased power, in most practical scenarios, it's probably going to be somewhere between 2.4 GHz Wi-Fi and 5 GHz Wi-Fi. Even when going from the street to a house, coverage is going to be spotty. It's mostly useful for bringing internet to a house without the need to run a cable. Like traditional wired internet, once it gets into the house, you really need a Wi-Fi network to get decent speeds and reliability. It's not something your phone will be connecting to directly throughout your entire house, but it will be able to reach a stationary modem located almost anywhere in a small- to medium-sized modern house.
- 5 GHz Wi-Fi can be extremely fast--upwards of 1 Gbps--but it also has very short range and is mostly only useful within a single room. Modern home networks work around this by creating a mesh network; an access point goes in each room, and traffic "bounces" between access points. Because of this, it's typically too expensive for big buildings, as it would require too many access points. Commercial deployments mostly stick to 2.4 GHz.
The relevance to domainers here is that the 5G hype is probably going to be short-lived, on the order of 3-5 years. Once the marketing hype dies down, people aren't going to be googling "phone with 5G support", just as they're not currently googling "phone with 4G support"--either it's going to become ubiquitous and everything is going to support (obviating the need to check), or it's going to die and nobody is going to want it. You're going to want to unload your domains before we reach that point.
If you want to aim for a slightly longer-term investment, 5G home internet won't see as much hype, but it will be longer-lived. In the coming years, consumers are going to have to make a choice: do they want wired internet in their homes, or do they want 5G? This is in contrast with the smartphone market, where there won't be a choice.