In telecommunication, the term chirping has the following meanings:
1. The rapid changing, as opposed to long-term drifting, of the frequency of an electromagnetic wave.
Chirping is most often observed in pulsed operation of a source.
2. A pulse compression technique that uses (usually linear) frequency modulation during the pulse.
3. A trademarked term in mobile communications used by Nextel and Boost Mobile for sending voice messages to a private number in push-to-talk or walkie-talkie mode.