Any recommended resources for learning about mobile communications technologies that aren't overpriced engineering certificates or surface level marketing material for / from telcoms?
Most of the learning curve comes from the lingo. Especially now that 5G introduces softwarization of many of the network functions, the terms used by the cellular and software industries clash and may be confusing at times. But you can definitely learn the high-level idea of how the cellular networks function in this way.
For physical level things, I imagine that a degree in signal processing is required. And for more advanced software interfaces, I am afraid that you can only read about them, as most devices on which the software is implemented is proprietary. The open-source software you can find is in no-way as fully implemented as the actual software which runs commercial networks.
lol, I've found a lot of terminology around digital communications seem to be confusing. Terms meaning two or three different things depending on context, etc.