Will 4G only capable iPhones be able to take advantage of 5G when it, finally, deploys? In other words will they just do as they’ve always done but in fasters waters, so to speak, or will they be able to do more?
From what I’ve heard, ISPs can offer a 4G lane along with a 5G lane so no customer is left behind. My guess is that it’s likely that most ISPs will go the multi lane route,
4G and 5G are completely distinct standards, and current 4G phones won’t be able to take advantage of any 5G features. They won’t even know the 5G network exists. Only 5G phones will be able to take advantage of the 5G network, and then of course only when your carrier adopts it in your area and if it works in your location (many more antennas are needed to get the same coverage, so even if it’s available in your area, it might not be available at your house, for example.)
There are incremental improvements to 4G being made, and if your carrier implements those, your 4G phone may be able to take advantage of them, but those are still built on 4G so are limited in how much improvement they can make.
Carriers are going to continue supporting 4G for a long time, so although your 4G device won’t see any of the 5G advantages, it’s not like it’s going to stop working either.
No, 5G will require new radios in the phones. LTE phones will only be able to use LTE (and 3G and older standards for as long as carriers support that.) 5G is not enhanced LTE - it’s a new technology.
The world of mobile radio communication is far more complicated and confusing than you can imagine. Terms like “4G” and “5G” are marketing terms that mean almost nothing with respect to the actual technology.
Manufacturers (including chips, phones, system software, etc.) build their devices to comply with a particular release, usually cherry-picking features from later releases. If you read product literature for wireless components, they will usually document something like “supports release 11 with some features from releases 12, 13 and 14”.
The “G” number marketing departments use will typically describe the “air interface” protocol. For example a “4G LTE” device implements release 8 (where LTE was introduced). A “5G” device usually supports the “5G New Radio” specification (introduced in release 15), but “5G” has also been used by companies like AT&T to mean LTE Advanced pro (introduced in release 13), marketing 5G New Radio capabilities as “5GE”.
Some “5G” features were defined and deployed before the New Radio spec and therefore may be available in an LTE phone that implements a suitable release - but your phone will still say “4G” (or LTE or whatever it normally displays), you’ll just see the higher throughput.
And even with a 5G phone, they’re not all equal. For example, the 5G New Radio spec can operate in any frequency band, including those that have been used for earlier generations. For instance, T-Mobile is running it in the 600 MHz band (previously used for 2G/GSM, I believe). It can also run in the millimeter-wave bands. But these different bands require very different kinds of hardware (antennas, filters, chipsets, etc.) A phone that supports 5G NR on the “sub-6” bands (6GHz and below) may or may not include the hardware needed to support the millimeter-wave bands.
And this is just talking about the air interface. There are dozens of additional specifications for equipment and services running in the central offices and application-level services. Some of these may be compatible with existing “4G LTE” hardware, needing only a software/firmware update while other features will not be.
Handset manufacturers, back-end equipment manufacturers, chipmakers and mobile operators each pick a set of features from this giant soup of possibilities, implementing what they think their customers want and skipping the rest (planning some for the future and having no plans for others).
But when you go shopping for a phone, you see none of it. You just see a glossy marketing brochure that says “5G”, keeping you blissfully unaware of the fact that the term means nothing without lots of additional technical information.
Nobody can stop AT&T from calling it that, but it still won’t be 5G. The answer to the original question: an iPhone without 5G radios and antennas (e.g., all current iPhones) cannot take advantage of 5G cell signals.
The original question was:
And the answer is “it depends on what you mean by ‘5G’”. Some features carriers deploy using the 5G moniker (e.g. LTE Advanced with 4x4 MIMO) may be compatible while others (the 5G New Radio protocols) will not be.
And almost no-one really needs 5G at present in a mobile phone - 4G is plenty fast enough and more importantly requires fewer masts to provide coverage than 5G at its full speed. Don’t be taken in by the hype - buy the technology you NEED rather than the technology the manufacturers create in order to try and persuade the gullible to buy the latest and “greatest”.