Patent ID: 8104058

Claim:
A method comprising: selectively tuning a tuner to any of multiple frequencies, wherein the tuner is simultaneously receiving multiple information streams, each of the information streams is carried on a different one of the multiple frequencies, each of the information streams includes data packets for a subset of multiple virtual channels and recurring, temporally-separated virtual channel tables, and each virtual channel table contains information that maps, as of the time the virtual channel table is received at the tuner, each of the multiple virtual channels to one of the multiple frequencies; extracting a prenotification message from the information stream carried in a currently-tuned frequency of the multiple frequencies, wherein the currently-tuned frequency is a frequency of the multiple frequencies to which the tuner is currently tuned, and the prenotification message contains information regarding an upcoming change of virtual channel table frequency mapping for at least one of the multiple virtual channels; determining, subsequent to extraction of the prenotification message, that data packets for a user-selected one of the virtual channels are not present on a first frequency of the multiple frequencies, wherein the first frequency was previously mapped to the user-selected virtual channel in a received virtual channel table; and identifying, based at least in part on the information in the received prenotification message, a second frequency of the multiple frequencies, wherein the second frequency carries an information stream that includes data packets of the user-selected virtual channel, and wherein the identifying step includes identifying a third frequency mapped to the user-selected virtual channel by the information in the received prenotification message, determining that data packets for the user-selected virtual channel are not present on the third frequency, identifying, based on the information in the received prenotification message, a non-moving virtual channel not mapped to a new frequency by the information in the received prenotification message, extracting a virtual channel table from an information stream that includes data for the non-moving virtual channel, and identifying the second frequency from the extracted virtual channel table.