Leaving a message on a held connection

DETAILED DESCRIPTION FIG.
1 is a system diagram illustrating the operation of applicants' invention in a number of its embodiments.
Shown are a switch 10 which is a central office switch.
Also shown is a private branch exchange (PBX) 30 located at a customer's premises for handling communications among stations of that customer and also for handling incoming and outgoing communications to and from the public switched telephone network (PSTN).
In order to illustrate one embodiment of the invention, telephone station 11 is shown which has an attached recording device 12.
This recording device can be readily adapted from existing answering machines.
This can be done, for example, by adding a supplementary outgoing announcement arrangement, triggered by a button indicating that a new message is to be recorded; following a transition by the telephone station from a held state to a state wherein incoming signals are detected, the new message is played.
The recording device performs a number of functions in applicants' embodiment.
When the user of telephone station 11 presses an appropriate button the recording device is alerted to record the message by the user of telephone station 11.
The end of the message is signaled by the user of telephone station 11 pressing another or the same button.
After a message has been recorded, the recording device continues to stay on the line connecting telephone station 11 to switch 10 even though telephone station 11 has gone on-hook.
As soon as recording device 12 recognizes that the holding party, i.
e.
, the party that placed telephone station 11 on hold, has gone from hold back to an active connection, recording device 12 will play the recorded message.
Recording device 12 detects the transition of the holding station back to the communicating mode by any of a number of well known methods, for example, by detecting the presence of signals in the voice band.
After the recording device has finished playing the message it will disconnect itself and telephone station 11 from the line to switch 10, thus enabling the user of telephone station 11 to re-originate and/or receive incoming calls