Dial-back call completion method and apparatus in a radio-communication system

A method for making a call connection in a communication system having multiple communication units, at least one satellite that predictably changes a position with respect to a surface of an earth, and at least one control facility, the method comprising the steps of:

• a) making a fast call attempt by a source communication unit to establish a communication path with a target communication unit, the communication path requiting establishment of a target link between the target communication unit and a satellite;
• b) determining whether the target link is successfully established;
• c) where the target link is not successfully established, calculating a future call opportunity when the target communication unit will have a better opportunity to support the target link because a predicted future position of one of the at least one satellite will have moved within an optimal call initiation area with respect to the target communication unit;
• d) attempting to contact the target communication unit during the future call opportunity;
• e) where attempting to contact the target communication unit is successful, requesting that the target communication unit hold while the source communication unit is contacted;
• f) contacting the source communication unit;
• and
• g) connecting the source communication unit and the target communication unit.

A method for establishing a communication path in a communication system having multiple communication units, at least one communication antenna that predictably changes a position with respect to a target communication unit, and at least one control facility, the method comprising the steps of:

• a) making a call attempt by a source communication unit to establish the communication path with a target communication unit, the communication path including a target link between the target communication unit and a target antenna that moves with respect to the target communication unit;
• b) where the call attempt is not successful, waiting for the communication system to attempt to contact the target communication unit during a future call opportunity during which the target communication unit will have a better opportunity to support the target link because a predicted future position of one of the at least one communication antenna will have moved within an optimal call initiation area with respect to the target communication unit;
• c) the source communication unit being contacted by the communication system when the communication system successfully contacts the target communication unit;
• and
• d) establishing the communication path with the target communication unit.

A call opportunity calculation apparatus comprising:

• a transceiver for sending messages to a source communication unit;
• a processor coupled to the transceiver for determining whether the source communication unit has successfully established a communication path with a target communication unit, the communication path including a target link between the target communication unit and at least one antenna that moves with respect to the target communication unit, the processor also for calculating a future call opportunity at which the source communication unit will have a better opportunity to establish the target link because a predicted future position of one of the at least one antenna will be within an optimal call initiation area with respect to the target communication unit, attempting to contact the target communication unit during the future call opportunity, where attempting to contact the target communication unit is successful, requesting that the target communication unit hold while the source communication unit is contacted, contacting the source communication unit, and connecting the source communication unit and the target communication unit;
• and
• a memory device coupled to the processor for storing information necessary to calculate the future call opportunity.