A method and apparatus for packet-data header decompression, particularly advantageous for use in connection with broadcast and multicast messages being transported through a radio telecommunication system operable according to the CDMA 2000 standard. When a mobile subscriber desires broadcast content from a content server, the mobile station sets up a PPP session for submitting the request and negotiating security protocols. When a subscription is granted, the mobile station receives broadcast content that has undergone header compression. In order to synchronize its decompressor, the mobile station receives a full header from a PDSN. The full header is preferably sent out on a periodic basis just for this purpose. The frequency of full-header transmissions by the PDSN is increased from a normal mode to a high full-header frequency (HFHF) mode upon receiving a request for a full header from a mobile station, but returns to normal-mode full-header transition frequency after receiving an ACK message from the requesting mobile indicating successful decompressor synchronization, or upon the expiration of a predetermined HFHF-mode maximum duration.