Patents by Inventor Prabhakar R. Chitrapu

Prabhakar R. Chitrapu 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).

  • Publication number: 20100137017
    Abstract: A method and apparatus for power control for distributed wireless communication is disclosed including one or more power control loops associated with a wireless transmit/receive unit (WTRU). Each power control loop may include open loop power control or closed loop power control. A multi-phase power control method is also disclosed with each phase representing a different time interval and a WTRU sends transmissions at different power levels to different set of node-Bs or relay stations during different phases to optimize communications.
    Type: Application
    Filed: November 30, 2009
    Publication date: June 3, 2010
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Zinan Lin, Alexander Reznik, Prabhakar R. Chitrapu, Mihaela C. Beluri, Eldad M. Zeira, Philip J. Pietraski, Sung-Hyuk Shin, Gregg A. Charlton
  • Publication number: 20100122085
    Abstract: A system and method for providing variable security levels in a wireless communication network. The present invention optimizes the often conflicting demands of highly secure wireless communications and high speed wireless communications. According to a preferred embodiment of the present invention, various security sensors are scanned to determine the likely presence of an intruder within a predetermined trust zone. If an intruder is likely present, the security level is changed to the highest setting, and consequently a lower data rate, while the intruder is identified. If the identified intruder is in fact a trusted node, the security level is returned to a lower setting. If the identified intruder is not a trusted node, the security level is maintained at an elevated state while the intruder is within the trust zone.
    Type: Application
    Filed: December 22, 2009
    Publication date: May 13, 2010
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Akinlolu Oloruntosi Kumoluyi, Alexander Reznik, Guodong Zhang, Prabhakar R. Chitrapu, Sung-Hyuk Shin, Yingming Tsai
  • Patent number: 7711364
    Abstract: A wireless communication system includes a base station that receives information regarding neighboring wireless systems and updates and stores this information for use in handover of user equipments (UEs).
    Type: Grant
    Filed: April 17, 2006
    Date of Patent: May 4, 2010
    Assignee: InterDigital Technology Corporation
    Inventors: Arty Chandra, Prabhakar R. Chitrapu, Narayan Parappil Menon
  • Patent number: 7657288
    Abstract: The present invention relates to a method and system using dynamic beam forming for wireless communication signals in a wireless network. Base stations and/or UEs are provided with antenna systems having a range of beam forming selections. Relative base station and UE locations are one type of criteria used to make beam forming decisions.
    Type: Grant
    Filed: December 22, 2005
    Date of Patent: February 2, 2010
    Assignee: InterDigital Technology Corporation
    Inventors: Prabhakar R. Chitrapu, Steven Jeffrey Goldberg
  • Publication number: 20100008287
    Abstract: A wireless communication method and apparatus are disclosed for assigning different phases, (i.e., time periods), to perform data transmissions over designated frequency bands in a cooperative relaying system. In phase 1, a relay station (RS) listens to a wireless transmit/receive unit (WTRU) and successfully receives b information bits. In phase 2, the RS and WTRU cooperatively transmit these b information bits to the destination. These transmissions may be performed in a unicast scheme, wherein a WTRU sends information to a selected RS in phase 1, and the RS forwards the information to a base station (BS) in phase 2. The transmission may also be performed in a multicast scheme, wherein the WTRU sends information to the RS and the BS in phase 1, and the RS transmits a subset the information to the BS in phase 2.
    Type: Application
    Filed: July 8, 2009
    Publication date: January 14, 2010
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Zinan Lin, Eldad M. Zeira, Alexander Reznik, Prabhakar R. Chitrapu, Sana Sfar
  • Publication number: 20100008283
    Abstract: A plurality of time frame structures that support the use of multicast cooperative relay schemes are disclosed. These time frame structures are used in IEEE 802.16j networks as well as other wireless networks. Furthermore, modifications to the frame structures used in IEEE 802.16j networks are disclosed.
    Type: Application
    Filed: July 8, 2009
    Publication date: January 14, 2010
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Prabhakar R. Chitrapu, Eldad M. Zeira, Mihaela C. Beluri
  • Publication number: 20100003977
    Abstract: A method and apparatus are used in cooperative relays with incremental redundancy (IR) and distributed spatial multiplexing. A wireless transmit/receive unit (WTRU) may listen to the base station (BS) transmission during Phase 1 of the communication, and use cooperation between a relay station (RS) and the BS for the data transmission during Phase 2 to improve performance. During Phase 2, both the BS and the RS may transmit data to the WTRU, using either distributed Space Time Block Codes/Space Frequency Block Codes (STBC/SFBC) or distributed spatial multiplexing.
    Type: Application
    Filed: July 7, 2009
    Publication date: January 7, 2010
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Ana Lucia Pinheiro, Sana Sfar, Prabhakar R. Chitrapu, Philip J. Pietraski, Alexander Reznik, Eldad M. Zeira, Mihaela C. Beluri
  • Patent number: 7636842
    Abstract: A system and method for providing variable security levels in a wireless communication network. The present invention optimizes the often conflicting demands of highly secure wireless communications and high speed wireless communications. According to a preferred embodiment of the present invention, various security sensors are scanned to determine the likely presence of an intruder within a predetermined trust zone. If an intruder is likely present, the security level is changed to the highest setting, and consequently a lower data rate, while the intruder is identified. If the identified intruder is in fact a trusted node, the security level is returned to a lower setting. If the identified intruder is not a trusted node, the security level is maintained at an elevated state while the intruder is within the trust zone.
    Type: Grant
    Filed: September 30, 2005
    Date of Patent: December 22, 2009
    Assignee: InterDigital Technology Corporation
    Inventors: Akinlolu Oloruntosi Kumoluyi, Alexander Reznik, Guodong Zhang, Prabhakar R. Chitrapu, Sung-Hyuk Shin, Yingming Tsai
  • Publication number: 20090303967
    Abstract: A wireless communication system includes a base station that receives information regarding neighboring wireless systems and updates and stores this information for use in handover of user equipments (UEs).
    Type: Application
    Filed: August 18, 2009
    Publication date: December 10, 2009
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Arty Chandra, Prabhakar R. Chitrapu, Narayan Parappil Menon
  • Publication number: 20090238145
    Abstract: A method and apparatus for supporting handover of mobile communications is provided. A router performs routing services in a service area. The router maintains a location table configured to store current router addresses of mobile nodes that have the router as a home router. The router receives data intended for mobile nodes that are listed in the location table and are in the routers service area. The router receives a user datagram protocol (UDP) message from a mobile node when it leaves the service area. The UDP message includes an IP address of a new router in the mobile node's new service area. The router updates the location table with the new IP address and transmits data intended for the mobile node to the new router until the data is redirected at the source.
    Type: Application
    Filed: March 30, 2009
    Publication date: September 24, 2009
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Sharif M. Shahrier, Prabhakar R. Chitrapu
  • Patent number: 7573890
    Abstract: A system and method for supporting mobile Internet communication is provided which employs a plurality of Routers and a plurality of Mobile Nodes (MNs). Each Router has a unique communication address. Each MN is associated with a home Router. Each Router has an associated Mobile Node Location List identifying each MN for which the Router is the home Router and the communication address of a Router corresponding to a current location of each such MN. Each MN is movable from an old location where the MN communicates with the Internet via one Router to a current location where the MN communicates with the Internet via a different Router. Communication at the current location via the different Router is established by communicating to the MN's home Router the communication address of the different Router as the communication address corresponding to the MN's current location.
    Type: Grant
    Filed: October 4, 2006
    Date of Patent: August 11, 2009
    Assignee: InterDigital Technolgy Corporation
    Inventors: Sharif M. Shahrier, Prabhakar R. Chitrapu
  • Publication number: 20090175214
    Abstract: A method and apparatus for cooperation in wireless communications. Cooperation is considered among a number of network elements, including at least one wireless transmit-receive unit, at least one relay station, and at least one base station.
    Type: Application
    Filed: December 31, 2008
    Publication date: July 9, 2009
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Sana Sfar, Alexander Reznik, Prabhakar R. Chitrapu, Zinan Lin, Mohammed Sammour, Ana Lucia Pinheiro, Mihaela C. Beluri, Chunxuan Ye, Yogendra C. Shah, Gregg A. Charlton, Guodong Zhang, Khushali N. Manseta, Ruiyuan Hu
  • Publication number: 20090163158
    Abstract: A wireless transmit receive unit (WTRU) configured to indicate REDHOT and HUGE multi-slot capability to a network. The REDHOT multi-slot capability is included in a MS Classmark 3 information element and a MS Radio Access Capability information element. In another embodiment, DLDC operation in an evolved GERAN system includes both single carrier and dual carrier modes. Monitoring in single carrier mode reduces battery consumption. Various techniques for enabling dual carrier mode are disclosed.
    Type: Application
    Filed: August 5, 2008
    Publication date: June 25, 2009
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Prabhakar R. Chitrapu, Marian Rudolf, Behrouz Aghili, Yan Li
  • Patent number: 7545780
    Abstract: At least one subscriber is subscribed to both a cellular network and a wireless local area network (WLAN). The subscriber is located in the WLAN. Flows of the subscriber are provided for transfer. Each flow comprises packets. For each flow a determination is made on whether that flow is to be routed directly through the WLAN or through both the WLAN and cellular network. Each flow's packets are routed based on that flow's routing determination.
    Type: Grant
    Filed: November 14, 2002
    Date of Patent: June 9, 2009
    Assignee: InterDigital Technology Corporation
    Inventor: Prabhakar R. Chitrapu
  • Publication number: 20090141782
    Abstract: A method for using orthogonal sub-channels (OSCs) in a wireless transmit/receive unit (WTRU). A capability report is received from the WTRU, including an indication whether the WTRU supports OSCs. A determination is made whether to use OSCs for the WTRU and the result of the determination is signaled to the WTRU. If OSCs are used with the WTRU, the signaling includes an OSC assignment for the WTRU. In one embodiment, two resources are assigned to the WTRU and each resource is assigned to a different OSC.
    Type: Application
    Filed: October 24, 2008
    Publication date: June 4, 2009
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Prabhakar R. Chitrapu, Behrouz Aghili, Marian Rudolf, Stephen G. Dick
  • Publication number: 20090135773
    Abstract: A method for accounting for the presence of a piggybacked acknowledgement/negative acknowledgement (PAN) field in reporting a received signal quality for a current wireless transmit/receive unit (WTRU) is disclosed. A determination is made whether a received radio block is intended for the current WTRU. The received signal quality of the radio block is measured if the radio block is intended for the current WTRU. Bits from the PAN field are included in determining the received signal quality of the radio block based on a preconfigured option. The radio block measurement is included in a measurement report if a data header of the radio block is not addressed to the current WTRU but the PAN field is addressed to the current WTRU.
    Type: Application
    Filed: November 13, 2008
    Publication date: May 28, 2009
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Behrouz Aghili, Marian Rudolf, Stephen G. Dick, Yan Li, Prabhakar R. Chitrapu
  • Patent number: 7532723
    Abstract: Tokens/keys are produced for wireless communications. These tokens/keys are used for watermarks, signature insertion, encryption and other uses. In one embodiment, contextual information is used to generate tokens/keys. The tokens/keys may be derived directly from the contextual information. The contextual information may be used in conjunction with other information to derive the tokens/keys. Tokens/keys may be exchanged between transmit/receive units. The exchange of these tokens/keys may be encrypted.
    Type: Grant
    Filed: November 23, 2004
    Date of Patent: May 12, 2009
    Assignee: InterDigital Technology Corporation
    Inventors: Prabhakar R. Chitrapu, Alain Charles Louis Briancon, Akinlolu Oloruntosi Kumoluyi, Alan Gerald Carlton, Kiran Kumar S. Vanganuru, Richard Dan Herschaft, John Erich Hoffmann, John Thommana, Debashish Purkayastha, Guodong Zhang, Robert Lind Olesen, Alexander Reznik, TieJun Shan, Sung-Hyuk Shin, Amit Singhal
  • Publication number: 20090086685
    Abstract: A method and apparatus for time-based fast positive acknowledgement (ACK)/negative acknowledgement (NACK) reporting (FANR) operation with enhanced general packet radio service 2 uplink (HUGE) are disclosed. A wireless transmit/receive unit (WTRU) configures downlink FANR operation and EGPRS-2 mode uplink transmission not to be in conflict. A modulation and coding scheme (MCS) for the EGPRS-2 mode may be limited to an MCS containing at most two RLC data blocks. Alternatively, three or more piggybacked ACK/NACK (PAN) bits may be used for a time-based FANR operation if an EGPRS-2 mode is configured. Alternatively, at least one PAN bit may indicate an ACK/NACK for a group of RLC data blocks. The number of PAN bits for a time-based FANR operation may be configured by the network. The downlink FANR operation may be dynamically switched between time-based and SSN-based.
    Type: Application
    Filed: September 30, 2008
    Publication date: April 2, 2009
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Behrouz Aghili, Marian Rudolf, Stephen G. Dick, Prabhakar R. Chitrapu
  • Publication number: 20090086686
    Abstract: A method and apparatus allow for reliable and low-complexity decoding of EGPRS2 communication bursts when RTTI and BTTI equipment operate on the same timeslot(s). Various configurations for the Uplink State Flag (USF) mapping employ adjustable bit swapping of some or all USF channel-coded bits in communication bursts. Configurations that allow for an adjustable use of the symbol mapping stage in the transmitter and receiver to allow for more throughput and/or reduced complexity are also disclosed. Admissible mapping rules are known to the receiver and transmitter and therefore reduce the complexity of decoding this information. In order to increase throughput for EGPRS2 communication bursts, RTTI transmissions of different modulation types or EGPRS/EGPRS2 modulation and coding schemes during a BTTI interval are introduced that allow for reliable USF decoding and reduced decoder complexity.
    Type: Application
    Filed: September 30, 2008
    Publication date: April 2, 2009
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Marian Rudolf, Stephen G. Dick, Prabhakar R. Chitrapu, Behrouz Aghili
  • Publication number: 20090080565
    Abstract: A method and apparatus are disclosed for wireless transmission using two or more pulse shaping filters. Wireless transmit/receive units (WTRUs) and network entities are capable of utilizing a narrow band pulse shaping filter, a wideband pulse shaping filter, or both. The network entity and/or the WTRU select a pulse shaping filter to be used and transmits the selection by means of signaling. The signaling may be performed through layer 2/3 messages or by using non-access stratum (NAS) signaling messages.
    Type: Application
    Filed: August 6, 2008
    Publication date: March 26, 2009
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Marian Rudolf, Behrouz Aghili, Stephen G. Dick, Prabhakar R. Chitrapu, Yan Li