Helicopter satellite communication system, helicopter-mounted communication apparatus, terrestrial station communication apparatus, communication method, and non-transitory computer-readable recording medium storing computer program

摘要

A helicopter-mounted communication apparatus (200) of a helicopter satellite communication system (1) encodes video data at a compression rate based on a percentage of the time in which a transmission beam is blocked by the rotor blades. When the number of video packets is less than a specified number, the helicopter-mounted communication apparatus (200) inserts null packets to keep the packet rate constant. The helicopter-mounted communication apparatus (200) then deletes the null packets and attaches additional information to another packet indicating the number of deleted null packets. After buffering, the helicopter-mounted communication apparatus (200) modulates and transmits the signal toward a communication satellite (300) at transmittable-time points during a transmittable period. A terrestrial station communication apparatus (100) receives the signal that is transmitted from the helicopter-mounted communication apparatus (200) via the communication satellite (300) and demodulates the received signal, thereby generating a packet stream. The terrestrial station communication apparatus (100), based on the additional information that is included in the generated packet stream, inserts null packets in the packet stream and buffers the packet stream, thereby keeping the packet rate constant. The terrestrial station communication apparatus (100) then separates the video packets from the packet stream and decodes the separated video packets.