Ruby Radio Links vs Radio Interfaces:

There are two concepts in Ruby related to the actual radio transmissions: radio links and radio interfaces.
A controller or a vehicle can have multiple physical radio interfaces. Based on those physical radio interfaces, multiple logical radio links are constructed between controllers and vehicles.
How ones relates to the others is explained in the following picture:

Radio Links vs Radio Interfaces

Radio links are independent of each other and each radio link is on a different frequency. This leads to better interference resistance.
The actual radio links configuration is accessible in the Ruby Menu, where user can change the parameters of the radio links and radio interfaces:

Ruby menu: Radio Configuration
Tip: All hardware components in Ruby are plug and play.
Ruby, at boot time, automatically detects all the hardware components present on the system and does configure automatically everything so that all the hardware components work right from the start, without the user having to do any configuration.
So, when you add or remove hardware components, Ruby automatically configures them and the system to match the new hardware configuration. You can still configure the settings of each hardware component as needed.

Related articles:
Radio Streams: How they work
Relay Radio Links: How they work