The Federal Communications Commission acronym OET stands for Office of Engineering and Technology. TCB stands for Telecommunications Certification Bodies. TCBs are Test Firms authorized to test and apply for certification of wireless equipment.
As of July 13, 2015, the OET (FCC’s Certification Lab) is no longer accepting applications for Certification of RF equipment and all FCC certifications must be directed through TCB (external testing bodies)
The technical requirements are generally specified in the applicable FCC rule parts and the administrative rules are specified in 47 CFR part 2, subpart J .