System and method for communicating using an in-vehicle system

1. A method to be used with first and second devices where the first and second devices are capable of communicating using a subset of different modulation schemes wherein the subset includes at least first and second different modulation schemes, the method for optimizing transmission of data from the first device to the second device, the method comprising the acts of:

at the first device, when data is to be transmitted from the first device to the second device:

receiving at least a portion of a trigger signal from the second device wherein the transmitted trigger signal includes data transmitted using a sequence of at least two of the modulation schemes from the subset, the portion of the trigger signal received being a received trigger signal;

analyzing the received trigger signal to identify one of the modulation schemes from the subset as a function of the received trigger signal as an initial modulation scheme to be used to transmit data to the second device; and

transmitting the data from the first device to the second device using the initial modulation scheme.

2. The method of claim 1 wherein the sequence of modulation schemes in the transmitted signal includes alternating first and second modulation schemes.

3. The method of claim 2 wherein the act of analyzing the received trigger signal includes identifying the number of times each of the first and second modulation schemes occurs in the received trigger signal and using the number of times each of the first and second modulation schemes occurs in the received trigger signal to identify the initial modulation scheme.

4. The method of claim 3 wherein the act of using the number of times each of the first and second modulation schemes occurs to identify the initial modulation scheme includes selecting the modulation scheme that occurs a relatively greater number of times as the initial modulation scheme.

5. The method of claim 4 wherein the first and second modulation schemes are a high rate data modulation scheme and a low rate data modulation scheme, respectively.

6. The method of claim 1 further including the acts of, after transmitting the data using the initial modulation scheme, continuing to receive the trigger signal and continuing to transmit the data to the second device until the trigger signal ceases.

7. The method of claim 6 wherein, after the data has been transmitted to the second device at least a first time using the initial modulation scheme, while the trigger signal is being received, the method further including transmitting the data to the second device using the other of the first and second modulation schemes.

8. The method of claim 1 wherein the trigger signal data includes a pseudorandom binary sequence.

9. The method of claim 1 wherein the trigger signal includes data transmitted using a sequence of at least three modulation schemes.

10. The method of claim 1 further including the acts of, prior to receiving at least a portion of the trigger signal, at the first device, determining that data is to be transmitted to the second device, transmitting an initial communication to the second device and monitoring for the trigger signal.

11. The method of claim 1 wherein the first device is an in vehicle communication system and the second device is a public safety answering point.

12. A mobile electronic device to be used with a second device where the mobile electronic device and the second device are capable of communicating using a subset of different modulation schemes wherein the subset includes at least first and second different modulation schemes, the mobile electronic device comprising:

a processor programmed to perform the acts of, when data is to be transmitted from the mobile electronic device to the second device:

receiving at least a portion of a trigger signal from the second device wherein the transmitted trigger signal includes data transmitted using a sequence of at least two of the modulation schemes from the subset, the portion of the trigger signal received being a received trigger signal;

analyzing the received trigger signal to identify one of the modulation schemes from the subset as a function of the received trigger signal as an initial modulation scheme to be used to transmit data to the second device; and

transmitting the data from the mobile electronic device to the second device using the initial modulation scheme.

13. The mobile electronic device of claim 12 wherein the sequence of modulation schemes in the transmitted signal includes alternating first and second modulation schemes and wherein the act of analyzing the received trigger signal includes identifying the number of times each of the first and second modulation schemes occurs in the received trigger signal and using the number of times each of the first and second modulation schemes occurs in the received trigger signal to identify the initial modulation scheme.

14. The mobile electronic device of claim 13 wherein the act of using the number of times each of the first and second modulation schemes occurs to identify the initial modulation scheme includes selecting the modulation scheme that occurs a relatively greater number of times as the initial modulation scheme.

15. The mobile electronic device of claim 12 wherein the trigger signal data includes a pseudorandom binary sequence.