Free-to-air Services - (Maybe known as, or associated with Off-air Signals, Free-to-view, OTA, Over-the-air, Terrestrial Television, Free-to-air Digital Television, Digital Terrestrial Television, Commercial Terrestrial Broadcaster) - Free-to-air Services are services accessible over the television (or other mediums) that are free and/or don’t necessarily need a special decoder/set-top box to be received. These might offer interactive TV.

See the Interactive Television Institute.