Subscriber identity module verification during power management

• US 20020120857A1
• Filed: 06/15/2001
• Published: 08/29/2002
• Est. Priority Date: 02/27/2001
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Hutchison, James A. IV, Summers, Tom, Krishnan, Chidambaram
• Granted Patent: US 7,137,003 B2
• Time in Patent Office: Days
• US Class Current: 713/193
• CPC Class Codes: H04M 17/02 Coin-freed or check-freed systems , e.g. mobile- or card-operated phones, public telephones or booths
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Power management techniques for a Subscriber Identity Module (SIM) of a wireless communication device (WCD) are described that make use of a unique identifier for the SIM. In particular, a processor within the WCD reads a first unique identifier from the SIM when power is initially supplied to the WCD, and stores the first unique identifier within a computer-readable medium within the WCD. During a power management cycle, where power is terminated and then re-supplied to the SIM, the processor again receives a unique identifier from the SIM and compares the second unique identifier with the stored unique identifier. These techniques are useful in detecting whether the attached SIM has been exchanged for a different SIM while powered down during a power management cycle. This is advantageous in verifying the integrity of the SIM for other software or hardware modules within the WCD that need to access or otherwise utilize the SIM.

Claims

1. A method comprising:

storing a first unique identifier within a wireless communication device (WCD);

receiving a second unique identifier for a subscriber identity module (SIM) coupled to the WCD upon supplying power to the SIM; and

controlling access to the SIM based on the first unique identifier and the second unique identifier.

2. The method of claim 1, wherein controlling access to the SIM includes restarting a security authorization process.

3. The method of claim 1, wherein controlling access comprises:

comparing the first unique identifier and the second unique identifier; and

permitting access to the SIM when the first unique identifier equals the second unique identifier.

4. The method of claim 1, wherein storing the first unique identifier comprises storing the first unique identifier when power is initially supplied to the WCD.

5. The method of claim 1, further comprising receiving the first unique identifier from a first SIM coupled to the WCD when power is supplied to the WCD.

6. The method of claim 1, wherein the first and second unique identifiers comprise Integrated Circuit Card Identifiers (ICCIDs).

7. A method comprising:

reading a first unique identifier from a subscriber identity module (SIM) coupled to a wireless communication device (WCD) when power is supplied to the WCD;

storing the first unique identifier within a computer-readable medium within the WCD;

terminating power to the SIM during a power management cycle;

receiving a second unique identifier from the SIM upon re-supplying power to the SIM during the power management cycle; and

controlling access to the SIM based on the first unique identifier and the second unique identifier.

8. The method of claim 7, wherein controlling access to the SIM includes restarting a security authorization process.

9. The method of claim 7, wherein restarting a security authorization process includes invalidating an access code cache.

10. The method of claim 7, wherein controlling access comprises:

comparing the first unique identifier and the second unique identifier; and

permitting access to the SIM when the first unique identifier equals the second unique identifier.

11. The method of claim 10, wherein controlling access further includes declaring the SIM card changed when the first unique identifier does not equal the second unique identifier.

12. The method of claim 7, wherein the SIM includes an interface circuit that interfaces with the WCD, and terminating power to the SIM includes terminating power to the interface circuit.

13. The method of claim 7, wherein storing the first unique identifier comprises storing the unique identifier in random access memory (RAM) within a modem within the WCD.

14. The method of claim 7, further comprising displaying a status of the SIM to a user based on the first and second unique identifiers.

15. The method of claim 7, wherein controlling access to the SIM comprises terminating power to the SIM when the first unique identifier does not equal the second unique identifier.

16. The method of claim 7, wherein the first and second unique identifiers comprise an Integrated Circuit Card Identifier (ICCID).

17. The method of claim 7, controlling access to the SIM comprises:

continuing the power management cycle by maintaining power to the SIM when the first unique identifier equals the second unique identifier; and

aborting the power-up process when the first unique identifier does not equal the second unique identifier.

18. The method of claim 7, wherein terminating power to the SIN comprises terminating power to the SIM in response to a power down command and based on a result from a voting process.

19. The method of claim 7, wherein terminating power to the SIM comprises terminating power to the SIM when no request is pending for service by the SIM and no software module running on the WCD requests maintenance of power to the SIM.

20. The method of claim 7, wherein the first and second unique identifiers comprise Integrated Circuit Card Identifiers (ICCIDs).

21. A computer-readable medium having instructions stored thereon for causing a processor to:

store a first unique identifier within a wireless communication device (WCD);

receive a second unique identifier for a subscriber identity module (SIM) coupled to the WCD upon supplying power to the SIM; and

control access to the SIM based on the first unique identifier and the second unique identifier.

22. The computer-readable medium of claim 21, wherein the instructions cause the processor to:

compare the first unique identifier and the second unique identifier; and

permit access to the SIM when the first unique identifier equals the second unique identifier.

23. The computer-readable medium of claim 21, wherein the instructions cause the processor to store the first unique identifier when power is supplied to the WCD.

24. The computer-readable medium of claim 21, wherein the instructions cause the processor to read the first unique identifier from a first SIM coupled to the WCD when power is supplied to the WCD.

25. The computer-readable medium of claim 21, wherein the first and second unique identifiers comprise Integrated Circuit Card Identifiers (ICCIDs).

26. The computer-readable medium of claim 21, wherein the instructions cause the processor to control access to the SIM includes restarting a security authorization process.

28. The wireless communication device of claim 27, wherein the processor permits access to the SIM when the first unique identifier equals the second unique identifier.

29. The wireless communication device of claim 27, wherein the first and second unique identifiers comprise Integrated Circuit Card Identifiers (ICCIDs).

30. The wireless communication device of claim 27, wherein the processor controls access to the SIM when the first unique identifier does not equal the second unique identifier

31. The wireless communication device of claim 27, wherein the processor terminates power to the SIM when the first unique identifier does not equal the second unique identifier.

32. The wireless communication device of claim 27, wherein the processor restarts a security authorization process when the first unique identifier does not equal the second unique identifier.

33. The wireless communication device of claim 27, further including an interface circuit that interfaces with the SIM and the wireless communication device, wherein the processor terminates power to the interface circuit when terminating power to the SIM.

27. A wireless communication device (WCD) comprising:

a memory to store a first unique identifier when power is initially applied to the WCD; and

a processor to receive a second unique identifier for a subscriber identity module (SIM) coupled to the WCD upon re-supplying power to the SIM during a power management cycle, and to control access to the SIM based on the first unique identifier and the second unique identifier.