| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that, when voice communications through the satellite lines are executed with an IP telephone, the transmission states of the satellite lines are significantly changed by the effects of the weather fluctuations, and as a result, the voice communications can not be executed. SOLUTION: The voice encoding standard of the IP telephone 1 is the ITU-T recommendations G.711. However, a relaying device 20 is provided which has an adaptive modulation/demodulation part 21 for monitoring the transmission states. The voice codes transmitted from the IP telephone 1 with a voice encoding system converting part 30 are converted to the voice codes with a narrow bandwidth by a transmission encoding converting part 33 following the deterioration of the transmission state. And, they are transmitted to the satellite lines. After reception, they are returned to the original voice codes with a reception encoding converter 36. And then, they are transmitted to the IP telephone 1 of the reception destination. COPYRIGHT: (C)2005,JPO&NCIPI |
