It seems that this agency specifies the recommended frequency bands in someway, but I don't think that is the extent of it. Is it?
I am answering your title - which does not seem to match your question.
Those covered ISDN & ISUP, then, later GSM, and GPRS.
Analog(ue) technology was considered to be first generation, and digital (ISN & ISUP) to be second (ISDN was between subscriber and exchange, and ISUP was between exchanges)).
When a new access stratum, which was much better suited to packet switching, was introduced and the 3GPP consortium was established to define world wide standards.
Fast forward to UMTS, whcih is 4G, and your history lesson is complete.
Like I said, that addresses your question title - the answer(s) to the question body may be different.
And, of course, this is not IoT specific