Method and apparatus for improving audio reception in a paging device

Abstract

A method ( 300 ) and apparatus ( 200 ) are provided for operating a portable pager. The method and apparatus eliminate channel noise between paging tones and voice messages. Channel noise is squelched between paging tones and voice messages using a delayed N timer, thereby allowing the speaker to remain on. Paging tones are received and played at the speaker during a signaling squelch mode of operation. The detection of the paging tones and subsequent drop in carrier signal, initiates a timer during which channel noise is squelched during a carrier squelch mode of operation. The timer is delayed (delay N timer) so as to expire only after the carrier frequency is re-established. Once the carrier signal is re-established followed by the delayed timer expiration, the carrier squelch is removed. The speaker remains on during both signaling squelch and carrier squelch. Hence, paging tones are heard, channel noise is silenced, and then voice messages are played.

We claim: 
     
       1. A method for controlling audio at a pager, comprising:
 monitoring at least one radio frequency (RF) channel; 
 detecting a predetermined radio frequency (RF) carrier frequency on a monitored RF channel; 
 receiving predetermined paging tones over the RF carrier frequency; 
 playing an alert tone at a speaker of the pager, the alert tone corresponding to the predetermined paging tones; 
 un-muting the speaker to the RF carrier frequency; 
 detecting when the RF carrier frequency drops, thereby generating channel noise, and starting a timer; 
 silencing the channel noise and starting a timer while the speaker remains on; 
 detecting the RF carrier frequency is re-established, the RF carrier now carrying a a voice message that un-silences the channel; 
 playing or recording the voice message; 
 detecting when the timer has expired; 
 detecting when the RF carrier carrying the voice message drops; and 
 muting the speaker prior to returning to monitoring. 
 
     
     
       2. The method of  claim 1 , wherein the predetermined paging tones comprise audible tones or vibrating tones. 
     
     
       3. The method of  claim 1 , wherein the pager is a portable, battery operated paging device. 
     
     
       4. The method of  claim 1 , further comprising:
 continuing to play the voice message after the timer has expired; 
 dropping the RF carrier once the voice message is complete; and 
 returning to monitoring the at least one RF channel. 
 
     
     
       5. The method of  claim 1 , wherein playing the predetermined paging tones at a speaker of the pager is done during a signaling squelch mode of operation which only permits the predetermined paging tones over the predetermined RF carrier frequency. 
     
     
       6. The method of  claim 5 , wherein silencing the channel noise is done during a carrier squelch mode of operation. 
     
     
       7. The method of  claim 6 , wherein the carrier squelch mode of operation is enabled in response to detecting a page, the page comprising the predetermined paging tones and the predetermined RF carrier frequency. 
     
     
       8. A pager, comprising:
 a receiver; and 
 a controller for controlling the receiver, the controller initiating carrier squelch operation upon detection of a predetermined radio frequency (RF) carrier frequency with predetermined paging tones, the carrier squelch operation remaining active for a predetermined time and remaining active when the predetermined RF carrier frequency is dropped and channel noise is generated, the carrier squelch operation silencing the channel noise, the predetermined time only expiring after the RF carrier frequency is re-established, and voice messages carried over the re-established RF carrier being played at speaker or recorded while the channel noise remains squelched. 
 
     
     
       9. The pager of  claim 8 , wherein the pager operates in a signaling squelch operation upon receipt of the paging tones, the signaling squelch operation playing the receiver's audio only in the presence of the predetermined RF carrier frequency and predetermined paging tones. 
     
     
       10. The pager of  claim 9 , wherein the pager returns to signaling squelch operation upon drop of the re-established RF carrier. 
     
     
       11. The pager of  claim 9 , wherein the speaker remains on throughout the signaling squelch operation and the carrier squelch operation. 
     
     
       12. The pager of  claim 8 , wherein both the predetermined RF carrier and the predetermined paging tones are required to receive a new page. 
     
     
       13. The pager of  claim 8 , wherein the pager is a portable, battery operated paging device.