radio frequency

The radio frequencies that would be used were secret.

A contracted helicopter team followed the radio frequency emitted by the collars and essentially chased the wolves down, sometimes netting them or darting them from the sky, according to Hunnicutt.

That doubling-up involved communicating with airplane and helicopter pilots on two separate radio frequencies, the Times reported.

But in northern England and Scotland, meters instead rely on radio frequencies and no such fix is available.

Adding to the chaos, the Secret Service and local law enforcement were apparently communicating on different radio frequencies throughout the event.