METHOD FOR IN-BAND SIGNALING OF DATA OVER DIGITAL WIRELESS TELECOMMUNICATIONS NETWORKS

• US 20080108389A1
• Filed: 01/07/2008
• Published: 05/08/2008
• Est. Priority Date: 05/19/1997
• Status: Active Grant

• Current Assignee: Karma Automotive LLC (Wanxiang Group Corporation)
• Original Assignee: Airbiquity Incorporated
• Inventors: Proctor, Rod, Leyendecker, Robert, Eatherly, Wayne, Preston, Dan, Preston, Joseph
• Granted Patent: US 7,747,281 B2
• Time in Patent Office: Days
• US Class Current: 455/557
• CPC Class Codes: G01S 2205/002 for traffic control, mobile tracking, guidance, surveillance or anti-collision
• CPC Class Codes: G01S 2205/008 using a mobile telephone network
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G08G 1/127 to a central station ; Indicators in a central station
• CPC Class Codes: H04M 11/066 Telephone sets adapted for data transmision
• CPC Class Codes: H04W 88/181 Transcoding devices; Rate adaptation devices

Abstract

An inband signaling modem communicates digital data over a voice channel of a wireless telecommunications network. An input receives digital data. An encoder converts the digital data into audio tones that synthesize frequency characteristics of human speech. The digital data is also encoded to prevent voice encoding circuitry in the telecommunications network from corrupting the synthesized audio tones representing the digital data. An output then outputs the synthesized audio tones to a voice channel of a digital wireless telecommunications network.

Claims

1. A software in-band signaling modem for receiving digital data over a digital voice channel of a wireless communications network, the software stored in a machine-readable medium in a hand-held device and comprising:

an input that receives voice signals over the voice channel of the wireless communications network;

a filter that detects synthesized tones representing the digital data that is interleaved with the voice signals transmitted over the digital voice channel, the synthesized tones synthesizing frequency characteristics of human speech and preventing voice encoding circuitry in the wireless telecommunications network from corrupting the digital data represented by the synthesized audio tones; and

a demodulator that converts the detected synthesized tones back into the represented digital data.

2. A software in-band signaling modem according to claim 1 wherein the filter includes:

a first in-band filter for detecting signals outside of a synthesized tone frequency band;

a second out of band filter for detecting signals inside the synthesized tone frequency band; and

a comparator that compares the signals detected outside the synthesized tone frequency band with the signals detected inside the synthesized tone frequency band and identifies signals as synthesized tones when the compared value is greater than a selected value.

3. A software in-band signaling modem according to claim 1 wherein the software is executable in a signal-processing apparatus in the hand-held device.

4. A software in-band signaling modem according to claim 1 wherein the software is executable in a digital processor in the hand-held device.

5. A hand-held, portable device comprising:

a cell phone component for communication via a wireless telecommunications network;

an in-band signaling modem coupled to the cell phone component to provide data communications over a voice channel connection of the wireless telecommunications network;

a GPS receiver to determine current location data of the portable device; and

wherein the GPS receiver is coupled to the in-band signaling modem to transmit current location data of the portable device over a voice channel connection of the wireless telecommunications network.

6. A hand-held, portable device according to claim 5 wherein the in-band signaling modem includes an input for receiving the current location data;

an encoder for converting the current location data into audible tones that synthesize frequency characteristics of human speech and prevent voice encoding circuitry in the telecommunications network from corrupting the digital data represented by the synthesized audio tones.

7. A hand-held, portable device according to claim 6 further comprising remote activation means for triggering the device to transmit the current location data in response to a signal received via the cell phone component.

8. A hand-held, portable device according to claim 6 wherein the encoder includes a packet formatter for formatting the digital data into in-band signaling packets including sacrificial bits.

9. A hand-held, portable device according to claim 8 wherein the packet formatter appends a postamble of bits to the ends of the in-band signaling packets for sacrificing to any encoding circuitry that would corrupt the synthesized tones.

10. A hand-held, portable device according to claim 9 wherein the device includes a processor and the in-band signaling modem is implemented in software stored in a memory on the device for execution in the processor.