Abstract: In a data communications system, including an infrastructure arranged to communicate over a data channel with a plurality of data terminals, a method of detecting data decryption errors in a data packet includes receiving an encrypted data packet (213); decrypting the encrypted data packet to provide a decrypted data packet; and comparing a reference value to a portion of the decrypted data packet to determine when a predetermined relationship is satisfied (221).

Abstract: In a data communications system operating on a registered data channel and including an infrastructure 100 and a subscriber terminal 115, a method of making a channel exit decision at the subscriber terminal includes: sampling 201 the registered data channel for a time period, preferably a signal time period and a data time each of which may be an adaptable time period to obtain a plurality of quality values, preferably signal values and data quality values; comparing 203, 213 each of the plurality of quality values to a threshold; and initiating 225 an exit procedure, preferably including a quick scan for a possible data channel, when a first number of the plurality of quality values obtained during the time period does not satisfy the threshold.

Abstract: In a data communication system (100) including infrastructure (101) arranged to communicate with a plurality of terminals (103) over a channel (109), a method of adaptable channel access practiced at a terminal (103) including determining an access priority value (303), responsive thereto ascertaining when the channel is available (305), and then executing a channel access attempt (307). The access priority value is determined with information received by the terminal or information available to the terminal.