Patents by Inventor Chidambaram Krishnan

Chidambaram Krishnan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7757094
    Abstract: A power management technique for a Subscriber Identity Module (SIM), makes use of a voting process to determine when to power-up and power-down the SIM. In particular, the voting process determines whether software modules running on a wireless communication device (WCD) require current or imminent access to the SIM. The voting process is designed to make more efficient use of the SIM without sacrificing performance. A modified security authorization process can be added, in which the WCD caches a user access code in memory for authenticating the user to the SIM to gain access to the secure features of the SIM. The security verification process avoids the need for the user to enter the access code each time the SIM is powered up in the course of the power management routine, reducing user inconvenience and maintaining performance.
    Type: Grant
    Filed: May 29, 2001
    Date of Patent: July 13, 2010
    Assignee: QUALCOMM Incorporated
    Inventors: Chidambaram Krishnan, James A. Hutchison, IV, Tom Summers
  • Patent number: 7194264
    Abstract: Wireless devices with different capabilities may use a single file containing multiple (e.g., two) PRLs for system selection and acquisition. A first PRL in the file has a first (e.g., IS-683-A) format and includes PRL information for, e.g., 1x systems. A second PRL has a second (e.g., IS-683-C) format and includes PRL information for, e.g., 1x and 1xEV-DO systems or just 1xEV-DO systems. A legacy wireless device supporting only IS-683-A would read and use the first PRL for system selection and acquisition and ignore the second PRL. A wireless device supporting IS-683-C would read the second PRL and (1) use the second PRL by itself if it contains PRL information for both 1x and 1xEV-DO systems or (2) combine the first and second PRLs to generate a combined PRL if the second PRL contains PRL information for only 1xEV-DO systems.
    Type: Grant
    Filed: January 25, 2005
    Date of Patent: March 20, 2007
    Assignee: Qualcomm, Incorporated
    Inventors: Yan Li, Chidambaram Krishnan, James A. Hutchison, Rotem Cooper
  • Patent number: 7137003
    Abstract: Power management techniques for a Subscriber Identity Module (SIM) of a wireless communication device (WCD) are described tat make use of a unique identifier for the SIM. In particu1ar 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 tecbniques are useful in detecting whether the attached SIM has been exchanged for a different SIM while powered down during a power management cycle.
    Type: Grant
    Filed: June 15, 2001
    Date of Patent: November 14, 2006
    Assignee: Qualcomm Incorporated
    Inventors: Chidambaram Krishnan, James A. Hutchison, IV, Tom Summers
  • Publication number: 20050227688
    Abstract: Wireless devices with different capabilities may use a single file containing multiple (e.g., two) PRLs for system selection and acquisition. A first PRL in the file has a first (e.g., IS-683-A) format and includes PRL information for, e.g., 1x systems. A second PRL has a second (e.g., IS-683-C) format and includes PRL information for, e.g., 1x and 1xEV-DO systems or just 1xEV-DO systems. A legacy wireless device supporting only IS-683-A would read and use the first PRL for system selection and acquisition and ignore the second PRL. A wireless device supporting IS-683-C would read the second PRL and (1) use the second PRL by itself if it contains PRL information for both 1x and 1xEV-DO systems or (2) combine the first and second PRLs to generate a combined PRL if the second PRL contains PRL information for only 1xEV-DO systems.
    Type: Application
    Filed: January 25, 2005
    Publication date: October 13, 2005
    Inventors: Yan Li, Chidambaram Krishnan, James Hutchison, Rotem Cooper
  • Publication number: 20020120852
    Abstract: A power management technique for a Subscriber Identity Module (SIM), makes use of a voting process to determine when to power-up and power-down the SIM. In particular, the voting process determines whether software modules running on a wireless communication device (WCD) require current or imminent access to the SIM. The voting process is designed to make more efficient use of the SIM without sacrificing performance. A modified security authorization process can be added, in which the WCD caches a user access code in memory for authenticating the user to the SIM to gain access to the secure features of the SIM. The security verification process avoids the need for the user to enter the access code each time the SIM is powered up in the course of the power management routine, reducing user inconvenience and maintaining performance.
    Type: Application
    Filed: May 29, 2001
    Publication date: August 29, 2002
    Inventors: Chidambaram Krishnan, James A. Hutchison, Tom Summers
  • Publication number: 20020120857
    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.
    Type: Application
    Filed: June 15, 2001
    Publication date: August 29, 2002
    Inventors: Chidambaram Krishnan, James A. Hutchison, Tom Summers