> Apple has been working on a 5G modem for what feels like a billion years, but other standards seem to be more democratized.
The main problem is the sheer age of mobile phone networks. A phone has to support everything from top-modern 5G down to 2G to be usable across the world, that's almost as much garbage that a baseband/modem FW/HW has to drag along as Intel has to with the x86 architecture.
And if that isn't complex enough, phones have to be able to deal with quirks of all kinds of misbehaving devices - RF is shared media after all, and there's devices not complying with the standard, the standards containing ambiguous or undefined behavior specs, completely third-party services blasting wholly incompatible signals around (e.g. DVB-T operates on frequencies in some countries that are used for phone service in other countries, and often on much much higher TX power than phone tower sites). If it can't handle that or, worse, disrupts other legitimate RF users, certification won't be possible.
But that experience in dealing with about 35 years worth of history is just one part of the secret sauce - that just makes the costs of entry for FOSS projects really huge (which is why all of these projects I'm aware of support only 4G and afterwards since that generation is the first one to throw away all the legacy garbage).
The other part of why there are so few vendors is patents, and there is a toooooon of patent holders for 5G [1], with the top holders being either Chinese or known for being excessively litigious (Qualcomm). And even assuming you manage to work out deals with all of the patent holders (because of course there is, to my knowledge at least, no "one stop shop" compared to say MPEG), you still have to get a design that fulfills your requirements for raw performance, can coexist peacefully with almost all other users of the RF spectrum to be power efficient at the same time. That is the main challenge for Apple IMHO - they have a lot of experience doing that with "classic" SoCs, but almost none for RF hardware, virtually all of that comes from external vendors.
The main problem is the sheer age of mobile phone networks. A phone has to support everything from top-modern 5G down to 2G to be usable across the world, that's almost as much garbage that a baseband/modem FW/HW has to drag along as Intel has to with the x86 architecture.
And if that isn't complex enough, phones have to be able to deal with quirks of all kinds of misbehaving devices - RF is shared media after all, and there's devices not complying with the standard, the standards containing ambiguous or undefined behavior specs, completely third-party services blasting wholly incompatible signals around (e.g. DVB-T operates on frequencies in some countries that are used for phone service in other countries, and often on much much higher TX power than phone tower sites). If it can't handle that or, worse, disrupts other legitimate RF users, certification won't be possible.
But that experience in dealing with about 35 years worth of history is just one part of the secret sauce - that just makes the costs of entry for FOSS projects really huge (which is why all of these projects I'm aware of support only 4G and afterwards since that generation is the first one to throw away all the legacy garbage).
The other part of why there are so few vendors is patents, and there is a toooooon of patent holders for 5G [1], with the top holders being either Chinese or known for being excessively litigious (Qualcomm). And even assuming you manage to work out deals with all of the patent holders (because of course there is, to my knowledge at least, no "one stop shop" compared to say MPEG), you still have to get a design that fulfills your requirements for raw performance, can coexist peacefully with almost all other users of the RF spectrum to be power efficient at the same time. That is the main challenge for Apple IMHO - they have a lot of experience doing that with "classic" SoCs, but almost none for RF hardware, virtually all of that comes from external vendors.
[1] https://www.statista.com/statistics/1276457/leading-owners-o...