| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce the storage capacity of storage sections in a system for transmitting compressed holding tone data on the storage sections of main systems to IP telephone terminals under holding to reproduce the compressed holding tone data as holding tone. <P>SOLUTION: In the course of holding the IP telephone terminals 10A1, 10B1, each of the main systems 50A, 50B informs the IP telephone terminals 10A1, 10B1 of information on a voice coding rule representing the compressibility of holding tone data stored in the respective self-storage sections 51 for modification. The compressed holding tone data on the self-storage sections 51 are sent to the IP telephone terminals 10A1, 10B1. The IP telephone terminals 10A1, 10B1 expand the compressed holding tone data at expansion rates meeting a voice coding rule informed by the self-storage sections 51. In addition, D/A conversion is applied to the expanded holding tone data to regenerate the expanded holding tone data as an analog holding tone signal. As a result, the storage sections of the main systems 50A, 50B require no storage of a plurality of compressed holding tone data. <P>COPYRIGHT: (C)2003,JPO</p> |
