Sending signaling messages to CDMA cellular mobile stations
View Patent ↗A method and apparatus for transmitting signaling messages over the communication channel to a CDMA mobile station. If a one-half, one-quarter, or one-eighth frame voice packet is to be transmitted, augmenting that packet with signaling information to form, essentially, a full rate frame; if no more than N consecutive full rate frames are detected, deferring transmission of the signaling message, and thereafter, if another full frame voice frame is detected, substituting a frame of signaling information for the full frame voice frame. Advantageously, using this arrangement, most short signaling messages can be transmitted to a CDMA mobile station with minimal voice impairment.
1. A method of multiplexing a signaling message with voice frames in communications between base stations and CDMA mobile stations, comprising the steps of:
(a) responsive to receipt of a partial voice frame from a source, adding a portion of said signaling message to the partial frame to form a full frame, prior to transmission of that frame to a CDMA mobile station and transmitting the formed full frame to said CDMA station;
(b) responsive to reception of a full voice frame, when a request to send forward a signaling message has been recognized, transmitting said full voice frame with no signaling information of said signaling message to the CDMA mobile station provided that no more than N such full voice frames have been consecutively transmitted without any signaling information being carried in partial voice frames, wherein N is a parameter defined for the method;
(c) testing to determine a number of full voice frames that have been consecutively transmitted without transmission of any signaling information in partial voice frames, while a signaling message is queued for transmission to said CDMA mobile station; and
(d) if said number is less than N, return to step (a);
(e) if said number is equal to or greater than N, substituting one signaling frame for a full voice frame and discarding the full voice frame for which the signaling frame is being substituted; and
(f) following the substitution, return to step (a).
2. The method of claim 1 wherein a high priority signaling message is transmitted as a series of full frame signaling messages.
3. The method of claim 2 wherein following the transmission of a high priority signaling message, a gap of P frames is introduced in which no signaling information is transmitted, wherein P is a parameter defined for said method.
4. The method of claim 1 wherein N=3.
5. A multiplexer for multiplexing a signaling message with voice frames in communications between base stations and CDMA mobile stations, comprising:
first means, responsive to receipt of a partial voice frame from a source, for adding a portion of said signaling message to the partial frame to form a full frame, prior to transmission of that frame to a CDMA mobile station and for transmitting the formed full frame to said CDMA station;
second means, responsive to reception of a full voice frame, when a request to send forward a signaling message has been recognized, for transmitting said full voice frame with no signaling information of said signaling message to the CDMA mobile station provided that no more than N such full voice frames have been consecutively transmitted without any signaling information being carried in partial voice frames, wherein N is a parameter defined for said multiplexer;
third means for testing to determine a number of full voice frames that have been transmitted without transmission of any signaling information in partial voice frames, while a signaling message is queued for transmission to said CDMA mobile station;
if said number is less than N, fourth means for returning to said first means;
if said number is equal to or greater than N, fifth means for substituting one signaling frame for one full voice frame and discarding the full voice frame for which the signaling frame is being substituted; and
following the substitution, sixth means for returning to said first means for testing.
6. The apparatus of claim 5 , wherein said multiplexer comprises means for transmitting a high priority signaling message as a series of full frame signaling messages.
7. The apparatus of claim 6 wherein following the transmission of a high priority signaling message, said multiplexer comprises means for introducing a gap of P frames in which no signaling information is transmitted;
wherein P is a parameter defined for said multiplexer.
8. The multiplexer of claim 5 wherein N=3.