I read an LPWA (Low Power Wide Area) article recently that referenced the recent completion of the NB-IoT, LTE Cat-M1 and EC-GSM-IoT standards by 3GPP.
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.
3GPP is a standards body. Back when I was first programming telephone exchanges, the US standards were set by BellCore and the European standards by the CCCIT, which was renamed as the IT-U.
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)).
ISCN was still circuit switched, and GPRS, which was packet switched, became known as 2.5 generation, since it used the same Access Stratum as ISDN.
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
