Analog radio
Analog FM is widely understood, often straightforward to troubleshoot, and can be useful when compatibility with older equipment matters.
Digital radio
Digital commercial radio systems can provide features such as unit identification, text/data functions, more flexible signaling and different approaches to spectrum use depending on the technology.
Compatibility matters
Two radios being on the same frequency does not guarantee they can communicate. The operating mode, signaling, bandwidth, digital protocol and other programming must be compatible.
Planning a migration
Before converting a working fleet, inventory the existing radios, determine which models support the intended mode, review licensing, decide whether mixed analog/digital operation is needed during the transition, and test coverage under real operating conditions.