-
公开(公告)号：DE69735635T2
公开(公告)日：2007-05-03
申请号：DE69735635
申请日：1997-11-13
Applicant: QUALCOMM INC
Abstract: 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 (11) monitors the incoming data for fax signals. If a fax is detected, the data processor (12) 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 (11) 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.
-
Patent Agency Ranking
公开(公告)号：DE69734523T2
公开(公告)日：2006-08-10
申请号：DE69734523
申请日：1997-12-05
Applicant: QUALCOMM INC
Abstract: A novel and improved method and apparatus for providing an interface to a digital wireless telephone system compatible with standard analog wire line fax machines is described. To process a fax, a source interface waits until an interface to a destination fax machine has been established before establishing an interface to a source fax machine. The source fax transmission rate must be less than or equal to the destination fax transmission rate and the data rate of the digital channel. To establish the source fax interface at the proper rate, the source interface first selects and initial data rate from a set of standard fax transmission rates. The source interface sends unacceptable rate (failure to train) messages to the source fax machine until the source fax transmission rate is less than or equal to the data channel rate and the destination fax transmission rate. During fax processing, the destination interface inserts non-printing data (fill bits) if the destination fax transmission rate is greater than the source fax transmission rate. Fill bits are also inserted to compensate for transmission delays.
-
公开(公告)号：DE69735635D1
公开(公告)日：2006-05-18
申请号：DE69735635
申请日：1997-11-13
Applicant: QUALCOMM INC
Abstract: 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 (11) monitors the incoming data for fax signals. If a fax is detected, the data processor (12) 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 (11) 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.
-
公开(公告)号：DE69731551T2
公开(公告)日：2005-10-20
申请号：DE69731551
申请日：1997-12-19
Applicant: QUALCOMM INC
Abstract: In a half-duplex communication system in which additional delays in the communication channel may cause a message collision between a message and a response, a timer based collision prevention circuit is utilized to prevent the message collision. The collision prevention circuit determines if the message transmitted by a communication device will be repeated. If the message is to be repeated, the collision prevention circuit sets a countdown collision timer to a predetermined period of time shorter than the shortest repetition interval of the repeated message. A response is only sent to the communication device if the collision timer has not expired. If the timer expires, the collision prevention circuit waits for the message to be retransmitted by the source device before sending the response to the communication device.
-
公开(公告)号：DE69734523D1
公开(公告)日：2005-12-08
申请号：DE69734523
申请日：1997-12-05
Applicant: QUALCOMM INC
Abstract: A novel and improved method and apparatus for providing an interface to a digital wireless telephone system compatible with standard analog wire line fax machines is described. To process a fax, a source interface waits until an interface to a destination fax machine has been established before establishing an interface to a source fax machine. The source fax transmission rate must be less than or equal to the destination fax transmission rate and the data rate of the digital channel. To establish the source fax interface at the proper rate, the source interface first selects and initial data rate from a set of standard fax transmission rates. The source interface sends unacceptable rate (failure to train) messages to the source fax machine until the source fax transmission rate is less than or equal to the data channel rate and the destination fax transmission rate. During fax processing, the destination interface inserts non-printing data (fill bits) if the destination fax transmission rate is greater than the source fax transmission rate. Fill bits are also inserted to compensate for transmission delays.
-
公开(公告)号：DE69731551D1
公开(公告)日：2004-12-16
申请号：DE69731551
申请日：1997-12-19
Applicant: QUALCOMM INC
Abstract: In a half-duplex communication system in which additional delays in the communication channel may cause a message collision between a message and a response, a timer based collision prevention circuit is utilized to prevent the message collision. The collision prevention circuit determines if the message transmitted by a communication device will be repeated. If the message is to be repeated, the collision prevention circuit sets a countdown collision timer to a predetermined period of time shorter than the shortest repetition interval of the repeated message. A response is only sent to the communication device if the collision timer has not expired. If the timer expires, the collision prevention circuit waits for the message to be retransmitted by the source device before sending the response to the communication device.
-
-
-
-
-
Search Results
6
records
(took 0.021 seconds)
