发明名称 |
Method and apparatus for detecting facsimile transmission |
摘要 |
A novel and improved method and apparatus for providing an interface to a digital wireless telephone system compatible with standard analog wire line telephones and analog wire line fax machines is disclosed. During a telephone call, a fax detector monitors the incoming data for fax signals. If a fax is detected, the data processor switches from processing the data as if it were voice to processing it as fax. In addition, the remote station is sent a signal notifying it to process the data as fax rather than voice. The fax detector operates by detecting the preamble of a V.21 message, present at the beginning of every fax call. Energy is measured in both frequencies of the BFSK signals. A decision is made by analyzing these energies and locating a specific pattern which repeats itself a sufficient number of times.
|
申请公布号 |
US5892816(A) |
申请公布日期 |
1999.04.06 |
申请号 |
US19960751190 |
申请日期 |
1996.11.15 |
申请人 |
QUALCOMM, INCORPORATED |
发明人 |
SIH, GILBERT C.;JOHN, JOHNNY K. |
分类号 |
H04N1/32;H04M1/725;H04M11/00;H04N1/327;(IPC1-7):H04M11/00 |
主分类号 |
H04N1/32 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|