What is a common method used to program radios without using a wired connection?

A common method used to program radios without using a wired connection is through a radio frequency link. This method allows radios to communicate wirelessly, enabling the programming of settings, channels, and configurations remotely. By utilizing the same frequencies used for regular communication, devices can send programming data effectively.

Infra-red communication, while capable of transmitting data wirelessly, is typically limited to line-of-sight applications and is not commonly used in radio programming. Bluetooth connectivity could also facilitate wireless programming but is often not the standard for radio devices, especially in more traditional or specialized settings. Wi-Fi access might offer bandwidth advantages, but it is not a standard method for directly programming radios in the field. Radio frequency links, on the other hand, align with the primary function of radios, making them especially suitable for this task. Thus, using a radio frequency link stands out as an appropriate choice for programming radios wirelessly.