Method and system for modem protocol discrimination

• US 20030144028A1
• Filed: 01/31/2002
• Published: 07/31/2003
• Est. Priority Date: 01/31/2002
• Status: Active Grant

• Current Assignee: General Motors LLC (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Crocker, Dwayne, Fraser, Ronald W.
• Granted Patent: US 7,224,998 B2
• Time in Patent Office: Days
• US Class Current: 455/557
• CPC Class Codes: H04L 5/1438 Negotiation of transmission parameters prior to communication modified according to link quality H04L1/0001
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

The invention provides a method of selecting a modem carrier type for data transmission over a wireless communication system. An incoming call is received from a mobile vehicle and then an initial carrier tone is sent to a mobile vehicle in response to the incoming call. A modem response signal is received from a vehicle modem in response to the initial carrier tone. The modem response signal is determined to be either an analog modem response signal or a digital modem response signal, and then the call is connected to either the analog modem or digital modem based on the modem response signal determination.

Claims

1. A method of selecting a modem carrier type for data transmission over a wireless communication system, comprising:

receiving an incoming call from a mobile vehicle;

sending an initial carrier tone to the mobile vehicle in response to the incoming call;

receiving a modem response signal from a vehicle modem in response to the initial carrier tone;

determining whether the modem response signal is one of an analog modem response signal or a digital modem response signal; and

connecting the call to one of an analog modem or a digital modem based on the modem response signal determination.

2. The method of claim 1 wherein the initial carrier tone is a nominally 2225 Hz tone.

3. The method of claim 1 wherein the modem response signal is a nominally 1270 Hz tone indicating an analog vehicle modem.

4. The method of claim 1 wherein the modem response signal is a connect request signal indicating a digital vehicle modem.

5. The method of claim 1 further comprising:

comparing a call routing number associated with the incoming call to a database of call routing numbers; and

sending the initial carrier tone if the call routing number does not match one of the call routing numbers in the database.

6. The method of claim 1 further comprising:

disabling the initial carrier tone upon detecting the modem response signal.

7. The method of claim 1 further comprising:

terminating the incoming call if no modem response signal is received in response to the initial carrier tone.

8. A wireless modem system for selecting a modem carrier type comprising:

means for receiving an incoming call from a mobile vehicle;

means for sending an initial carrier tone to the mobile vehicle in response to the incoming call;

means for receiving a modem response signal from a vehicle modem in response to the initial carrier tone;

means for determining whether the modem response signal is one of an analog modem response signal or a digital modem response signal; and

means for connecting the call to one of an analog modem or a digital modem based on the modem response signal determination.

9. The system of claim 8 further comprising:

means for comparing a call routing number associated with the incoming call to a database of call routing numbers; and

means for sending the initial carrier tone if the call routing number does not match with one of the call routing numbers in the database.

10. The system of claim 8 further comprising:

means for disabling the initial carrier tone upon detecting the modem response signal.

11. The system of claim 8 further comprising:

means for terminating the incoming call if no modem response signal is received in response to the initial carrier tone.

12. A computer usable medium including a program for selecting a modem carrier type, comprising:

computer program code for receiving an incoming call from a mobile vehicle;

computer program code for sending an initial carrier tone to the mobile vehicle in response to the incoming call;

computer program code for receiving a modem response signal from a vehicle modem in response to the initial carrier tone;

computer program code for determining whether the modem response signal is one of an analog modem response signal or a digital modem response signal; and

computer program code for connecting the call to one of an analog modem or a digital modem based on the modem response signal determination.

13. The computer usable medium of claim 12 wherein the initial carrier tone is a nominally 2225 Hz tone.

14. The computer usable medium of claim 12 wherein the modem response signal is a nominally 1270 Hz tone indicating an analog vehicle modem.

15. The computer usable medium of claim 12 wherein the modem response signal is a connect request signal indicating a digital vehicle modem.

16. The computer usable medium of claim 12 further comprising:

computer program code for comparing a call routing number associated with the incoming call to a database of call routing numbers; and

computer program code for sending the initial carrier tone if the call routing number does not match with one of the call routing numbers in the database.

17. The computer usable medium of claim 12 further comprising:

computer program code for disabling the initial carrier tone upon detecting the modem response signal.

18. The computer usable medium of claim 12 further comprising:

computer program code for terminating the incoming call if no modem response signal is received in response to the initial carrier tone.