While it is possible for a phone that uses the 4G network to upgrade to 5G, it is advisable not to give it a try for now as the technology is still at the early stage of its development. To upgrade your smartphone to 5G is just a matter of installing software that will enable this. But 5G networks are yet to be rolled out to the masses.
Only those who can afford smartphones that support 5G networks are the ones enjoying the technology for now. For now, this upgrade is not possible because 5G is still very new, and a lot of updates and improvements will still be done on it.
For you to use the technology, you can either go for a new smartphone that supports it or by upgrading your smartphone to the kind that can accommodate both 5G and 4G networks. With this, you can start enjoying both the 4G and 5G networks.
Right now, 5G networks are called non-stand alone, and they need 4G as the preliminary introduction between a phone and a network before the device is passed along to a 5G connection. You need your network provider to enable this upgrade. The establishment of a true 5G network will take several years to be able to work on their own because they still rely on 4G to give them the boost they need to work.
Therefore, you could not consider that there is a true 5G upgrade. For the full transition from 4 to 5G to take effect, it will take ten years or more. However, right now, phones have dual captivity, which allows them to run on both 4G and 5G networks. For now, if you want to go from 4G to 5G, you need a 5G device and a 5G network plan.
If you would like to upgrade your current 4G phone to 5G, the best thing for you to do is to wait for the software update. The update can turn the network to 5G, but there are some people who think that this is not the best thing to do right now, especially since 5G is still in its premature stage.
Another thing that you can do is to upgrade the phone that you have. There are phones that can run on both 4G and 5G signals, and having this phone will allow your network to switch from 4G to 5G depending on which will fit better given your current situation.