Over-the-air programming (OTA) refers to various methods of distributing new software updates, configuration settings, and even updating encryption keys to devices like cellphones, set-top boxes or secure voice communication equipment (encrypted 2-way radios). One important feature of OTA is that one central location can send an update to all the users, who are unable to refuse, defeat, or alter that update, and that the update applies immediately to everyone on the channel. A user could "refuse" OTA but the "channel manager" could also "kick them off" the channel automatically.