Method for in-band signaling of data over digital wireless telecommunications networks

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.

1 . A mobile device comprising:
 a wireless telecommunication network access component (NAC) for communication via a wireless telecommunications network;   an in-band signaling modem coupled to the NAC to provide data transfer over a voice channel connection of the wireless telecommunications network, the in-band signaling modem including an input for receiving current location data, and 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; and   a GPS receiver to determine current location data of the mobile device, the GPS receiver coupled to the in-band signaling modem to provide current location data of the mobile device over a voice channel connection of the wireless telecommunications network.   
   
   
       2 . The mobile device of  claim 1  and further comprising remote activation means for triggering the mobile device to transmit the current location data in response to a trigger signal received via the wireless telecommunication network access component (NAC). 
   
   
       3 . The mobile device of  claim 2  and wherein the trigger signal is encoded in audio tones and transmitted in the voice channel during a voice channel session. 
   
   
       4 . The mobile device of  claim 2  and wherein the trigger signal is detected from live human speech from a call taker in the voice channel during a voice channel session. 
   
   
       5 . The mobile device of  claim 2  and wherein the in-band signaling modem provides both encoding and decoding of data to and from audio tones that synthesize frequency characteristics of human speech. 
   
   
       6 . The mobile device of  claim 2  and wherein the in-band signaling modem further comprises a packet formatter for formatting the location data into in-band signaling packets. 
   
   
       7 . The mobile device of  claim 6  and wherein the in-band signaling packets include sacrificial bits. 
   
   
       8 . The mobile device of  claim 6  and wherein the packet formatter appends a postamble of bits to the in-band signaling packets for sacrificing to encoding circuitry to avoid loss of data. 
   
   
       9 . The mobile device of  claim 6  and wherein the in-band signaling modem is implemented in software stored in a memory in the mobile device for execution in a processor. 
   
   
       10 . The mobile device of  claim 9  and wherein the software is arranged to implement—
 a filter that detects synthesized tones representing the digital data that is interleaved with human 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.