You would probably need a good overview of the technologies in use. I can very much recommend the book "From GSM to LTE"[0]. It goes through all the networks ba

You would probably need a good overview of the technologies in use. I can very much recommend the book "From GSM to LTE"[0]. It goes through all the networks back from GSM and up to LTE, which are needed, since all are in fact still in use. After that you could probably keep an eye on telecom news sites to follow the ongoing things and regulations. That should at least get you going. [0] https://books.google.dk/books/about/From_GSM_to_LTE.html?id=QNyrjwEACAAJ&hl=da https://books.google.dk/books/about/From_GSM_to_LTE.html?id=...