Camp-on busy signal

In telecommunication, the term camp-on busy signal has the following meanings:


 * A signal that informs a busy telephone user that another call originator is waiting for a connection. Synonym: call waiting
 * A teleprinter exchange facility signal that automatically causes a calling station to retry the call-receiver number after a given interval when the call-receiver teleprinter is occupied or the circuits are busy. Synonym: speed-up tone