METHOD AND APPARATUS FOR PROVIDING PUSH-TO-TALK SERVICES IN A CELLULAR COMMUNICATION SYSTEM

摘要

To reduce a delay between a time that a user of an originating mobile station (MS) (102) requests to set up a Push-To-Talk (PTT) call and a time that the user may begin to speak, a communication system (100) provides a 'wake up list' of other mobile stations (MSs) (103, 104) that may be awakened prior to the originating MS requesting to set up a PTT call. To further reduce the delay, the user may begin speaking prior to completion of the call setup. The speech is stored and is conveyed to a called MS when the call is setup. If the call does not get setup or a user of the called MS is not present, the stored speech may be conveyed to the called MS as a voice message. The stored speech, or new speech, may also be used as an announcement of a call.