| 摘要 |
<p>A global communications system is described having terrestrial transmitters (1108) for transmitting coded message signals in each of a plurality of geographic areas (1102, 1104, 1106). The global communication system further includes at least one satellite transmitter (1114) for transmitting the coded messages signals in each of a plurality of global geographic areas. The coded message signals transmissions include channel identification codewords identifying the terrestrial channels and the satellite channel. The terrestrial channel is selected for operation when the channel identification codeword received matches a first predetermined channel identification codeword. The satellite channel is selected for operation when the channel identification codeword does not match a second predetermined channel identification codeword. The terrestrial channel is periodically reselected when the channel identification codeword received on the satellite channel matches the second predetermined channel identification codeword.</p> |
