Patents by Inventor Subir Das

Subir Das 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: 9526040
    Abstract: A method of employing an encoding scheme for media independent handover, comprising: having at least some data type carry only required information to determine the end of data without a length value.
    Type: Grant
    Filed: May 12, 2008
    Date of Patent: December 20, 2016
    Assignees: TOSHIBA AMERICA RESEARCH, INC., TELCORDIA TECHNOLOGIES, INC.
    Inventors: Yoshihiro Oba, Subir Das, Yuu-Heng Alice Cheng, Miriam Tauil, Kenichi Taniuchi
  • Patent number: 9094412
    Abstract: A self-organizing IP multimedia subsystem exhibiting node splitting and node merging functions wherein any node within the self organizing IP multimedia subsystem may assume any role thereby providing node balancing and fault tolerance to an overall network.
    Type: Grant
    Filed: April 30, 2010
    Date of Patent: July 28, 2015
    Assignee: Telecordia Technologies, Inc.
    Inventors: Ashutosh Dutta, Dana Chee, Christian Makaya, Subir Das, Fuchun Joseph Lin, Ming Lai, Tsunehiko Chiba, Satoshi Komorita, Hidetoshi Yokota
  • Patent number: 9025771
    Abstract: A mechanism by which handoff delay can be minimized while not compromising the IMS/MMD security and also protecting the media if required by certain applications is presented. Methods for mitigating delay during SA re-association and mitigating the IPSec tunnel overhead for signaling and media at the Mobile Node are given. In one embodiment, SA keys can be transferred from the old P-CSCF to new P-CSCF, enabling the establishment of SAs before Mobile Node physically moves to the new subnet in a network. Proactive handover is used. In another embodiment, SA keys are transferred from S-CSCF to new P-CSCF. In this case, the SA keys are transferred to the new P-CSCF by S-CSCF through a context transfer mechanism well in advance so that SAs may be established before Mobile Node physically moves to new subnet. In another embodiment, methods for mitigating IPSec tunnel overhead are presented.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: May 5, 2015
    Assignee: Telcordia Technologies, Inc.
    Inventors: Ashutosh Dutta, Abhrajit Ghosh, Subir Das, Fuchun Joesph Lin, Kyriakos Manousakis, Dana Chee, Tsunehiko Chiba, Hidetoshi Yokota, Akira Idoue
  • Patent number: 8971291
    Abstract: A mechanism by which handoff delay can be minimized while not compromising the IMS/MMD security and also protecting the media if required by certain applications is presented. One proactive method includes proactive authentication. Another proactive method includes proactive security association, such as transferring SA keys from old proxy to new proxy, or transferring keys through serving signal entities. Reactive methods include transferring SA keys from old proxy to new proxy, using either push or pull technology. Other reactive methods include transferring keys through serving signal entities using either push or pull technology.
    Type: Grant
    Filed: December 12, 2011
    Date of Patent: March 3, 2015
    Assignees: Telcordia Technologies, Inc., KDDI Corporation
    Inventors: Ashutosh Dutta, Abhrajit Ghosh, Subir Das, Dana Chee, Kyriakos Manousakis, Funchun Joseph Lin, Shih-wei Li, Tsunehiko Chiba, Hidetoshi Yokota, Akira Idoue
  • Patent number: 8971239
    Abstract: A mobile device includes: multiple interfaces that are configured to support a various access technology such as 3G or Wi-Fi etc. A public land mobile network (PLMN) selector that generates a list for each of the PLMN networks that provide coverage to the mobile device. A PLMN selection policy parameter that is set to True or False to allow or prohibit the selection of PLMN networks by the mobile device based on the generated list where the generated list includes information as to different access technologies and selection priorities supported on the PLMN access networks providing coverage to the mobile device. In particular, when the PLMN selection policy parameter is set to True, multiple PLMN registrations are allowed; and when the A PLMN selection policy parameter is set to False, multiple PLMN registrations are prohibited.
    Type: Grant
    Filed: August 24, 2010
    Date of Patent: March 3, 2015
    Assignees: Kabushiki Kaisha Toshiba, Telcordia Technologies Inc.
    Inventors: Yoshihiro Oba, Raquel Morera, Subir Das
  • Patent number: 8929330
    Abstract: In some of the preferred embodiments, a method for network discovery of a mobile device to use at least one of a plurality of access networks within an IP network includes: obtaining specified network information in the vicinity of a given location based on a set of criteria when a mobile is connected to the IP network from any location.
    Type: Grant
    Filed: April 20, 2009
    Date of Patent: January 6, 2015
    Assignees: Toshiba America Research, Inc., Telcordia Technologies, Inc.
    Inventors: Kenichi Taniuchi, Yoshihiro Ohba, Sunil Madhani, Subir Das, Ashutosh Dutta
  • Patent number: 8886935
    Abstract: According to some embodiments, a key management apparatus for deploying in a smart grid system adapted to receive metering data from smart meters connected to at least one relay via a network, includes: a key control mechanism that derives a key array of individual purpose specific keys from one master key such that the purpose specific key in the key array are each independent cryptographic keys for each specific usage in an application or for each application if there is only one specific usage in an application.
    Type: Grant
    Filed: March 23, 2011
    Date of Patent: November 11, 2014
    Assignees: Kabushiki Kaisha Toshiba, Telcordia Technologies Inc.
    Inventors: Yoshihiro Ohba, Mitsuru Kanda, Subir Das, David Famolari
  • Patent number: 8781473
    Abstract: A solution framework is employed that includes defining of a mechanism to run multiple queries in a single message exchange, along with a priority on a per-query basis. In some embodiments, a system for facilitating handover of a mobile device across heterogeneous access networks by ensuring response to queries transmitted by the mobile device includes: a) a mobile device having a plurality of wireless network interfaces for communicating over a plurality of heterogeneous access networks, having a media independent handover (MIH) entity to facilitate handovers between the heterogeneous networks, and configured to transmit queries related to handover operation between the heterogeneous access networks to MIH entities within said heterogeneous access networks; and b) said media independent handover entity of said mobile device being configured to transmit multiple queries in a single message exchange to an MIH entity in an access network with prioritization among said multiple queries.
    Type: Grant
    Filed: December 23, 2011
    Date of Patent: July 15, 2014
    Assignees: Toshiba America Research, Inc., Telecordia Technologies, Inc.
    Inventors: Yoshihiro Oba, Yuu-Heng Alice Cheng, Subir Das, Kenichi Taniuchi
  • Patent number: 8717931
    Abstract: In some of the preferred embodiments, a method for network discovery of a mobile device to use at least one of a plurality of access networks within an IP network includes: obtaining specified network information in the vicinity of a given location based on a set of criteria when a mobile is connected to the IP network from any location.
    Type: Grant
    Filed: November 7, 2005
    Date of Patent: May 6, 2014
    Assignees: Toshiba America Research, Inc., Telcordia Technologies, Inc.
    Inventors: Kenichi Taniuchi, Yoshihiro Ohba, Sunil Madhani, Subir Das, Ashutosh Dutta
  • Patent number: 8707416
    Abstract: The preferred embodiments involve a mechanism to bootstrap Kerberos from EAP in which EAP is used for initial network access authentication and Kerberos is used for provisioning session keys to multiple different protocols. The preferred embodiments make use of an EAP extension method (EAP-EXT) to realize the mechanism.
    Type: Grant
    Filed: November 24, 2007
    Date of Patent: April 22, 2014
    Assignees: Toshiba America Research, Inc., Telcordia Technologies, Inc
    Inventors: Yoshihiro Oba, Subir Das
  • Patent number: 8681648
    Abstract: A packet data network gateway device may receive packet network data at a packet data network gateway device; filter the received packet network data to extract information associated with one or more messages in the packet network data; analyze the extracted information; and dynamically determine one or more of policy updates, rules, or thresholds based on the analyzing of the information and information associated with one or more of subscribers, location, existing policies, network operating condition and load.
    Type: Grant
    Filed: March 23, 2011
    Date of Patent: March 25, 2014
    Assignees: Telcordia Technologies, Inc., Kabushiki Kaisha Toshiba
    Inventors: David Famolari, Subir Das, Yoshihiro Ohba
  • Patent number: 8670407
    Abstract: A system and method for route optimization in PMIP having a first mobile node having a local mobility anchor and anchored at an access router and a second mobile node anchored at an access router is presented. The method includes establishing a binding cache at one access router comprising a mapping of mobile node addresses to access router addresses, populating the binding cache, and updating the mapping of the mobile node addresses in response to a handoff of a mobile node from one access router to another access router, so that a packet is transmitted from the first mobile node to the second mobile node using the mapping in the binding cache. The second access router address is obtained by either transmitting the packet from the first mobile node to the local mobility anchor, or querying neighboring access routers, or broadcasting access router addresses from the local mobility anchor.
    Type: Grant
    Filed: January 30, 2008
    Date of Patent: March 11, 2014
    Assignees: Telcordia Technologies, Inc., KDDI Corporation
    Inventors: Ashutosh Dutta, Funchun Joe Lin, Subir Das, Dana Chee, Hidetoshi Yokota, Tsunehiko Chiba
  • Patent number: 8625551
    Abstract: A system and method for mobility support of a mobile node having a home network in a heterogeneous roaming environment is presented. The method comprises the steps of authenticating the mobile node in a visited network and obtaining an address for the mobile node in the visited network, establishing a security connection between a functional component in the visited network and an agent in the home network, creating a home address for the mobile node, and using the home address to generate a SIP signaling address, a SIP media address, and a non-SIP media address, such that SIP non-media is transmitted using the security connection to the SIP signaling address, SIP media is transmitted using the security connection to the SIP media address, and non-SIP media is transmitted using the security connection to the non-SIP media address.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: January 7, 2014
    Assignees: Telcordia Technologies, Inc., KDDI Corporation
    Inventors: Ashutosh Dutta, Subir Das, Fuchun Joe Lin, Dana Chee, Tsumehiko Chiba, Hidetoshi Yokota, Akira Idoue
  • Patent number: 8611280
    Abstract: A system and method for network selection procedures for simultaneous network connectivity through multiple accesses comprises obtaining stored and registered PLMNs, determining whether PLMNs are both stored PLMN for access technology type Ai and registered PLMN, when no PLMNs are both, performing PLMN selection using a standard procedure, when only one PLMN is both, determining whether the PLMN satisfies a condition, and when the PLMN satisfies the condition, attempting to connect to the PLMN, and when more than one PLMN is both, creating a set of PLMNs, selecting one PLMN that satisfies the condition, from the set PLMN, attempting to connect to the selected PLMN, and when attempting to connect fails, removing the selected PLMN from the set, and selecting another PLMN. In one aspect, the PLMN that minimizes changes is selected. In one aspect, the PLMN that provides access to a larger number of access technologies is selected.
    Type: Grant
    Filed: January 13, 2011
    Date of Patent: December 17, 2013
    Assignees: Telcordia Technologies, Inc., Kabushiki Kaisha Toshiba
    Inventors: Raquel Morera, Subir Das, Yoshihiro Ohba
  • Patent number: 8583923
    Abstract: This document describes an EAP method used for extending EAP functionality. The extended functionality includes channel binding and re-authentication. The EAP method also allows sequencing of multiple EAP methods inside it.
    Type: Grant
    Filed: October 4, 2007
    Date of Patent: November 12, 2013
    Assignees: Toshiba America Research, Inc., Telcordia Technologies, Inc.
    Inventors: Yoshihiro Oba, Subir Das
  • Patent number: 8565186
    Abstract: The present invention advantageously provides several systems and methods for solving the trombone routing issues within an IMS/MMD network. These approaches avoid trombone routing, speed up handoff, and increase the efficiency of signaling and overall performance of an IMS/MMD network. These solutions can broadly be divided into the following categories. Piggy-backing SIP registration over MIP (Split at FA); Selective Reverse Tunneling and Tunneling between FA and P-CSCF; the SIP-based mobility protocol; use of CoA during SIP registration and call up in MIPv6; Piggy-backing SIP registration when HA and S-CSCF Co-exist; Using Dynamic Home Agents in MIPv4 FA-CoA; and the Interceptor-Caching Approach.
    Type: Grant
    Filed: August 31, 2007
    Date of Patent: October 22, 2013
    Assignees: Telcordia Technologies, Inc., KDDI Corporation
    Inventors: Ashutosh Dutta, Abhrajit Ghosh, John Lee, Subir Das, Joe Lin, Kyriakos Manousakis, Tsunehiko Chiba, Hidetoshi Yokota, Akira Idoue
  • Patent number: 8505076
    Abstract: A system for proactively authenticating includes a server having media independent access functions including media independent authentication functions that authenticates other entities attached via an interface to an end of a link specific to a media. A plurality of heterogeneous networks each having media specific access functions including authentication functions corresponding to the other entities attached via the interface to the end of the link specific to the media and mobile devices connected to the plurality of heterogeneous networks, and the server having predefined media independent handover protocols and media independent handover identities based on the media independent functions related to handover, in which the server authenticates candidate access networks prior to the handover of the mobile devices from serving access networks to the candidate access networks each of which belonging to the plurality of heterogeneous access networks having the link specific to the media.
    Type: Grant
    Filed: May 3, 2010
    Date of Patent: August 6, 2013
    Assignees: Kabushiki Kaisha Toshiba, Telcordia Technologies, Inc.
    Inventors: Subir Das, Yoshihiro Oba, Ashutosh Dutta
  • Patent number: 8442005
    Abstract: In a telecommunications network in which a mobile handset is capable of communicating in both an IP domain and a non-IP domain, the handoff of an existing communications session between the mobile handset and a fixed user is facilitated by a handoff controller implemented in a service control point. The handoff controller implements different handoff methods depending on the status of the fixed user and the transition of the mobile user. Additionally 802.21 Media Independent Handover Function in conjunction with SIP is used to facilitate handover between IP and Non-IP points in the system.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: May 14, 2013
    Assignee: TTI Inventions C LLC
    Inventors: Ashutosh Dutta, Subir Das, Donald R. Lukacs, Tao Zhang, David C. Shrader, Raquel Morera Sempere, Stephanie Demers, Bryan J. Lyles, James Alfieri
  • Patent number: 8341395
    Abstract: An apparatus for providing security to media independent handover service includes a point of service for providing the media independent handover services including an independent authenticator. The independent authenticator authenticates candidate access networks prior to the handover of the mobile devices from serving access networks to the candidate access networks, where each of the serving access networks and the candidate access networks belong to a plurality of heterogeneous access networks having the specific serving media. An access controller applies an access control through an access authentication with the point of service providing the media independent handover services through an authentication server, in which when the access authentication is established between the point of service and the authentication server, the mobile devices are authorized to access the media independent handover services through the point of service for the mobile devices attached between heterogeneous media.
    Type: Grant
    Filed: May 3, 2010
    Date of Patent: December 25, 2012
    Assignees: Kabushiki Kaisha Toshiba, Telcordia Technologies, Inc.
    Inventors: Subir Das, Yoshihiro Oba, Ashutosh Dutta
  • Patent number: 8332923
    Abstract: A media-independent handover key management architecture is disclosed that uses Kerberos for secure key distribution among a server, an authenticator, and a mobile node. In the preferred embodiments, signaling for key distribution is based on re-keying and is decoupled from re-authentication that requires EAP (Extensible Authentication Protocol) and AAA (Authentication, Authorization and Accounting) signaling similar to initial network access authentication. In this framework, the mobile node is able to obtain master session keys required for dynamically establishing the security associations with a set of authenticators without communicating with them before handover. By separating re-key operation from re-authentication, the proposed architecture is more optimized for a proactive mode of operation. It can also be optimized for reactive mode of operation by reversing the key distribution roles between the mobile node and the target access node.
    Type: Grant
    Filed: January 10, 2008
    Date of Patent: December 11, 2012
    Assignees: Toshiba America Research, Inc., Telcordia Technologies, Inc.
    Inventors: Yoshihiro Oba, Subir Das