Mobile data telephone

• US 5,257,397 A
• Filed: 08/13/1990
• Issued: 10/26/1993
• Est. Priority Date: 08/13/1990
• Status: Expired due to Term

• Current Assignee: American Telephone & Telegraph Company (AT&T, Inc.)
• Original Assignee: AT&T, Inc.
• Inventors: Schroeder, Robert E., Barzegar, Farhad, Russell, Jesse E., Eryaman, Can A.
• Primary Examiner(s): Dwyer, James L.
• Assistant Examiner(s): URBAN, EDWARD F
• Application Number:
  US07/566,733
• Time in Patent Office: 1,170 Days
• Field of Search: 455/33.1, 455/52.1, 455/52.2, 455/52.3, 455/56.1, 455/50.1, 455/63, 455/67.3, 455/69, 379/59, 379/60
• US Class Current: 455/553.1
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A mobile data telephone capable of transmitting and/or receiving voice and/or data signals over cellular communication channels or other air interfaces comprises a radio transceiver and a data modem in the same physical package. The transceiver and the modem have their respective controllers coupled so that they are effectively linked to achieve control of data transfer therebetween. In response to communication channel conditions in the air interface, the data flow between the modem and an audio processor of the transceiver can be selectively altered yielding high performance and high quality data transfer rates in the presence of severe channel impairments.

Claims

1. A mobile data telephone for transmitting and receiving voice and data signals over communication channels using an air interface comprising:

a radio transceiver including a first processor for processing voice and data signals, a second processor for processing system message signals, and first control means connected to said first and second processors and the first control means including means for detection of communication channel conditions;

a data modem connected to the transceiver and including a third processor, second control means connected to the third processor and a data port connected to supply data, via the second control means to the first processor during good communication channel conditions;

means for coupling the first control means and the second control means so that the transceiver and the data modem are linked to achieve control of data therebetween;

means for coupling the means for detection to the second control means;

the second control means, responsive to the means for detection, determining an adverse communication channel condition by interrupting direct data flow from the second control means to the first processor and controlling data flow to flow between the data port and the first processor via the third processor and the third processor including signal coding means for adding data protective coding to the data.

2. A mobile data telephone according to claim 1 wherein the signal coding means includes an error correcting protocol processor for adding protective coding to the data.

3. A mobile data telephone according to claim 2, wherein the protocol processor utilizes a forward error correction encoding technique.

4. A mobile data telephone according to claim 3, wherein the protocol processor includes an encoder of the Reed-Solomon type.

5. A wireless data transmission system for operation with mobile radiotelephones in a transmission environment subject of frequently occurring fading conditions including signal level attenuations and mobile movement-related signal degradations, comprising:

a transceiver apparatus including a voice and data processing unit, a transceiver controller for controlling throughput of the voice and data processing unit, and including channel condition monitoring means for detecting substandard channel conditions;

a data modem apparatus including a data input/output port, a data processing circuit including a modulator/demodulator, and a data modem controller for constructing frames of data signals for transmission;

the data modem controller responsive to the channel signal condition monitoring means for selecting a data path for controllably coupling the data input/output port to the voice and data processing unit via,

a first means for coupling the data modem throughput to the voice and data processor via a direct connection between the data modem controller and the voice and data processor during acceptable signal conditions,

a second means for coupling the data modem throughput to the voice and data processor via a connection including a sending of data to the data processing circuit for encoding the signal to enhance its accuracy during adverse signal conditions and coupling the encoded signal to the data modem controller and from thence to the voice and data processor; and

means for controlling the first and second means for coupling in response to system conditions.

6. A wireless data transmission system according to claim 5, wherein the means for controlling comprises means for adding coding protection to the signal when transmission is via the second means for coupling in response to predetermined channel impairments.

7. A wireless data transmission system according to claim 6 wherein the means for adding coding protection utilizes a forward error correction encoding scheme.

8. A wireles data transmission system according to claim 5, wherein the means for controlling comprises means for temporarily disabling the data modem in response to the unavailability of an audio communication path.