Patents by Inventor Ramachandran Ramjee

Ramachandran Ramjee 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: 6085086
    Abstract: The present invention is a user process that resides in network nodes to act as an agent for mobile terminals in, for example, PCS environments. The user process handles negotiation and complex signaling functions for the user, thus reducing the amount of signaling traffic that must travel over the valuable air interface. To achieve low call establishment times the user process is migrated as user move. Three embodiment is adapted to enable data sizes which are to be transferred to be optimized, leading to low overhead. This approach also provides flexibility when migrating across heterogeneous environments. A second alternative embodiment may be advantageously utilized when a program is compute intensive and asynchronous migration is essential. The third embodiment provides high reliability in the form of checkpointing, but incurs a high migration delay and has high memory requirement for network processors.
    Type: Grant
    Filed: June 27, 1997
    Date of Patent: July 4, 2000
    Assignee: Lucent Technologies Inc.
    Inventors: Thomas F. La Porta, Ramachandran Ramjee, Malathi Veeraraghavan
  • Patent number: 6081715
    Abstract: A system for distributed control in wireless cellular and personal communication systems includes separate servers for performing call control and connection control functions, thereby obviating the need for a mobile switching or other switch to be anchored for the duration of a call. During a registration procedure, visiting location servers track only roaming mobiles, rather than tracking both roaming mobiles as well as mobiles located in their home network. Direct signalling links between servers and base stations, or other servers, located in different networks allow roaming mobiles to contact their home networks for service at all times, thereby obviating the need for passing signalling information for mobiles when they are not involved in a call. The use of multicast signalling with asynchronous transfer mode switches, permits specified channel control functions to take place concurrently in channel servers associated with base station and switches that form a segment of the route for a call.
    Type: Grant
    Filed: March 18, 1997
    Date of Patent: June 27, 2000
    Assignee: Lucent Technologies Inc.
    Inventors: Thomas F. La Porta, Ramachandran Ramjee, Malathi Veeraraghavan
  • Patent number: 5884174
    Abstract: Improved wireless telephone call admission methods for admitting new and/or handoff calls into a wireless telephone network having a plurality of communications channels. One such method, fractional guard channel call admission, effectively reserves a non-integral number of guard channels for handoff calls by rejecting new calls in accordance with a probability value that is dependent upon the current channel occupancy. Fractional guard channel call admission results in a significant reduction of new call blocking when a fixed constraint is placed on the handoff call blocking probability. Fractional guard channel call admission also provides improvements over the integral guard channel policy by minimizing the number of required channels when fixed constraints are placed on both the new call blocking probability and the handoff call blocking probability.
    Type: Grant
    Filed: June 7, 1996
    Date of Patent: March 16, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Ramesh Nagarajan, Ramachandran Ramjee, Donald Fred Towsley
  • Patent number: 5659544
    Abstract: A system for distributed control in wireless cellular and personal communication systems includes separate servers for performing call control and connection control functions, thereby obviating the need for a mobile switching or other switch to be anchored for the duration of a call. During a registration procedure, visiting location servers track only roaming mobiles, rather than tracking both roaming mobiles as well as mobiles located in their home network. Direct signalling links between servers and base stations, or other servers, located in different networks allow roaming mobiles to contact their home networks for service at all times, thereby obviating the need for passing signalling information for mobiles when they are not involved in a call. The use of multicast signalling with asynchronous transfer mode switches, permits specified channel control functions to take place concurrently in channel servers associated with base station and switches that form a segment of the route for a call.
    Type: Grant
    Filed: October 17, 1994
    Date of Patent: August 19, 1997
    Assignee: Lucent Technologies Inc.
    Inventors: Thomas F. La Porta, Ramachandran Ramjee, Malathi Veeraraghavan