Method and apparatus for providing roaming instructions to data communication receivers

A data communication receiver for receiving roaming instructions, the data communication receiver comprising:

• a receiving circuit for receiving a signal comprising frames of data, the signal containing frame offset information;
• a memory coupled to the receiving circuit for storing a base frame number associated with a base frame during which the data communication receiver is assigned to wake for message reception;
• and
• a processor coupled to the memory for computing a substitute frame number from the frame offset information, wherein the substitute frame number is associated with a substitute frame that is relative in location to the base frame and that is located within the signal received by the data communication receiver, and wherein the data communication receiver is to wake for message reception thereafter in the substitute frame rather than the base frame.

A message transmission device for providing, within a predetermined geographic area, a signal that contains roaming instructions and that comprises frames of data, the message transmission device comprising:

• a memory for storing frame offset information for provision to data communication receivers;
• a database for storing base frame numbers associated with base frames in which the data communication receivers are assigned to receive messages;
• a batcher coupled to the memory for hatching the frame offset information into a frame of data;
• and
• a transmitter coupled to the batcher for transmitting the frame including the frame offset information, wherein the frame offset information indicates substitute frames that are relative in location to base frames of the data communication receivers and that are located within the signal received by the data communication receivers, and wherein roaming receivers of the data communication receivers are to thereafter wake for message reception in the substitute frames rather than the base frames of the roaming receivers.