The ban affects wireless microphones that operate in the 700 MHz band of the electromagnetic spectrum. This frequency band was formerly allocated for analog television broadcasts. However, with the completion of the transition to digital broadcasting last year, the band has been reassigned for use by public safety entities, and by commercial providers of wireless services.
In addition to wireless microphones, the ban also applies to equipment for “low power auxiliary stations” that can transmit over distances of 100 meters. Such equipment includes certain wireless intercoms, wireless in-ear monitors, wireless audio instrument links and wireless cueing equipment.