Patents by Inventor Inhyok Cha

Inhyok Cha 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: 20080090572
    Abstract: A technique is applied to increase secret bit generation rate for a wireless communication. A wireless transmit/receive unit (WTRU) measures channel impulse responses (CIRs) on downlink and generates secret bits based on the CIRs. Each of the network entities also measures a CIR on uplink between itself and the WTRU. On the network side, the network entities forward the CIRs on uplink to an aggregation controller, which generates secret bits based on the uplink CIRs. Alternatively, in a cooperative network, a cooperating node may measure CIRs on channels with a source node and a destination node and generate secret bits. The cooperating node then sends the secret bits to the destination node so that the secret bits are used for communication between the source and destination nodes. The secret bits are further characterized by a joint randomness not shared with others (JRNSO).
    Type: Application
    Filed: October 11, 2007
    Publication date: April 17, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Inhyok Cha, Yogendra C. Shah, Chunxuan Ye
  • Publication number: 20080089518
    Abstract: A secret stream of bits begins by receiving a public random stream contained in a wireless communication signal at a transmit/receive unit. The public random stream is sampled and specific bits are extracted according to a shared common secret. These extracted bits are used to create a longer secret stream. The shared common secret may be generated using JRNSO techniques, or provided to the transmit/receive units prior to the communication session. Alternatively, one of the transmit/receive unit is assumed to be more powerful than any potential eavesdropper. In this situation, the powerful transmit/receive unit may broadcast and store a public random stream. The weaker transmit/receive unit selects select random bits of the broadcast for creating a key. The weaker transmit/receive unit sends the powerful transmit/receive unit the selected bit numbers, and powerful transmit/receive unit uses the random numbers to produce the key created by the weaker transmit/receive unit.
    Type: Application
    Filed: October 12, 2007
    Publication date: April 17, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Alexander Reznik, Alain Briancon, Yevgeniy Dodis, Yogendra Shah, Chunxuan Ye, Robert DiFazio, Inhyok Cha
  • Publication number: 20080072287
    Abstract: A method and system for performing trust evaluation for a mobile software agent on a trusted computing platform are disclosed. A sending entity, which includes a mobile software agent, verifies if a receiving entity is trustworthy before transferring the mobile software agent to the receiving entity. The receiving entity may verify the state and details of the mobile software agent and/or the state of the sending entity, and receive the mobile software agent if the state of the mobile software agent and the sending entity are trustworthy. The mobile software agent may include its own virtual trusted platform module (TPM) which is tied to an agent's identity. The agent's virtual TPM is part of the agent and transferred along with the mobile code when the mobile code is transferred.
    Type: Application
    Filed: April 10, 2007
    Publication date: March 20, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Sasidhar Movva, Richard Dan Herschaft, Inhyok Cha
  • Publication number: 20080059804
    Abstract: A method and apparatus for password management and single sign-on (SSO) access based on trusted computing (TC) technology. The methods implement the Trusted Computing Group (TCG)'s trusted platform module (TPM), which interacts with both proxy SSO unit and web-accessing applications to provide a secure, trusted mechanism to generate, store, and retrieve passwords and SSO credentials. The various embodiments of the present invention allow a user to hop securely and transparently from one site to another that belong to a pre-identified group of sites, after signing on just once to a secured proxy residing at the user's device.
    Type: Application
    Filed: August 22, 2007
    Publication date: March 6, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Yogendra Shah, Inhyok Cha, Alexander Reznik
  • Publication number: 20080046758
    Abstract: The present invention discloses several methods to strengthen the integrity of entities, messages, and processing related to content distribution as defined by the Open Mobile Alliance (OMA) Digital Rights Management (DRM). The methods use techniques related to the Trusted Computing Group (TCG) specifications. A first embodiment uses TCG techniques to verify platform and DRM software integrity or trustworthiness, both with and without modifications to the DRM rights object acquisition protocol (ROAP) and DRM content format specifications. A second embodiment uses TCG techniques to strengthen the integrity of ROAP messages, constituent information, and processing without changing the existing ROAP protocol. A third embodiment uses TCG techniques to strengthen the integrity of the ROAP messages, information, and processing with some changes to the existing ROAP protocol.
    Type: Application
    Filed: May 4, 2007
    Publication date: February 21, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Inhyok Cha, Amit Singhal, Yogendra Shah
  • Publication number: 20080002627
    Abstract: A client station in a wireless local area network (WLAN) communication system includes a beam commutation algorithm and a smart antenna responsive to the beam commutation algorithm for selecting one of a plurality of directional antenna beams. The smart antenna is configured as a virtual omni-directional antenna by using a commutation of switched directional antenna beams. A switched directional antenna system that performs a commutation sequencing can be blind to environmental conditions and changes.
    Type: Application
    Filed: May 24, 2007
    Publication date: January 3, 2008
    Applicant: InterDigital Technology Corporation
    Inventors: Inhyok Cha, Keith Baldwin, Yingxue Li
  • Publication number: 20070273589
    Abstract: A communications device operates in a wireless local area network (WLAN), and includes a processor operating in accordance with an operating system that includes a standardized set of object identifiers (OIDs) associated therewith. An antenna steering algorithm is executed by the processor for generating a driver query. A driver generates an antenna query in response to the driver query. A smart antenna is driven by the driver and generates antenna beams for receiving signals, and generates metrics based upon the received signals. The smart antenna provides to the driver a metric associated with the antenna query. The driver associates the metric received from the smart antenna with one of the object identifiers from the standardized set of object identifiers, and provides the same to the antenna steering algorithm.
    Type: Application
    Filed: May 23, 2006
    Publication date: November 29, 2007
    Inventors: John S. Chen, Inhyok Cha, Richard Simeon, Daniel P. Steinbach
  • Publication number: 20070266256
    Abstract: The present invention is related to a wireless transmit/receive unit (WTRU) for providing advanced security functions. The WTRU includes trusted platform module (TPM) for performing trusted computing operations; and a secure time component (STC) for providing a secure measurement of a current time. The STC and the TPM are integrated to provide accurate trusted time information to internal and external to the WTRU. The STC may be located on an expanded a subscriber identity module (SIM), on the WTRU platform, or two STCs may be used, one in each location. Similarly, the TPM may be located on an expanded SIM, on the WTRU platform, or two TPMs may be used, one in each location. Preferably, the STC will include a real time clock (RTC); a tamper detection and power failure unit; and a time report and sync controller.
    Type: Application
    Filed: May 8, 2007
    Publication date: November 15, 2007
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Yogendra Shah, Inhyok Cha
  • Patent number: 7289828
    Abstract: A smart antenna steering algorithm performs a periodic re-scan at an end of a sustained use period and before a next sustained use period. During a sustained use period, a re-scan of the other antenna beams is not performed. The periodic re-scan is performed on alternate antenna beams that were selected when the preferred antenna beam was selected. The steering algorithm monitors a quality metric of the alternate antenna beams as well as a quality metric for the preferred antenna beam. If the quality metric of the preferred antenna beam is less than the quality metrics of anyone of the alternate antenna beams, then the alternate antenna beam corresponding to the quality metric having a higher value is selected for the next sustained use period.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: October 30, 2007
    Assignee: InterDigital Technology Corporation
    Inventors: Inhyok Cha, Zheng Zhao, Thomas Eric Gorsuch, Ross L. Lintelman
  • Publication number: 20070211671
    Abstract: A method and apparatus for a flexible physical random access channel (PRACH) preamble are disclosed. A wireless transmit/receive unit (WTRU) transmits a PRACH preamble generated by using a scrambling code and a signature code to a Node B to access the channel. The WTRU incorporates PRACH access information and preamble channel resources into the preamble, thereby providing flexibility and efficiency in transmission of the PRACH preamble. The method and apparatus may also be applied to an acquisition indicator channel preamble, a high speed uplink packet access channel preamble, an orthogonal frequency division multiplexing preamble, or an orthogonal frequency division multiple access preamble.
    Type: Application
    Filed: March 9, 2007
    Publication date: September 13, 2007
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventor: Inhyok Cha
  • Publication number: 20070165736
    Abstract: A method and apparatus for selecting a beam combination of beam switched antennas in a multiple-input multiple-output (MIMO) wireless communication system including a first node and a second node. The first node sends a plurality of modulation and coding scheme (MCS) requests to the second node. Each of the plurality of MCS requests is sent using a particular beam combination. The second node receives the MCS requests and generates MCS feedback signals for each of the MCS requests. Each MCS feedback signal includes an MCS recommendation for the particular beam. The first node selects a beam combination for communicating with the second node based on the MCS recommendations.
    Type: Application
    Filed: March 16, 2006
    Publication date: July 19, 2007
    Applicant: InterDigital Technology Corporation
    Inventors: Jin Wang, Arty Chandra, Inhyok Cha, Yingxue Li
  • Patent number: 7236759
    Abstract: An antenna steering algorithm for a smart antenna uses signal quality metrics and link quality metrics for selecting a preferred antenna beam. The link quality metrics supplement the signal quality metrics for improving the antenna steering decision. The link quality metrics are based on information available from existing counters operating in the media access control (MAC) layer. Separate estimates of the frame error rates in the receive links and in the transmit links are obtained. One estimate is the downlink quality metric (DLQM) and another estimate is the uplink quality metric (ULQM). Alternative link quality metrics are based on throughput and data rates of the exchanged data.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: June 26, 2007
    Assignee: InterDigital Technology Corporation
    Inventors: Inhyok Cha, Zheng Zhao, Thomas Eric Gorsuch, Ross L. Lintelman
  • Patent number: 7200376
    Abstract: A smart antenna steering algorithm operates in response to different functions monitored by the media access control (MAC) layer within a client station. One function is when the MAC layer indicates that the client station has been placed in a power savings mode. In response, the antenna algorithm stores an index of the currently selected antenna. Another function is when the MAC layer indicates that the client station has not been synchronized, associated and authenticated with an access point. In response, the algorithm selects an omni-directional antenna beam as the default antenna beam. Another function is when the MAC layer provides beacon period synchronization information to the antenna steering algorithm so that the algorithm can update its own timer.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: April 3, 2007
    Assignee: InterDigital Technology Corporation
    Inventors: Inhyok Cha, Zheng Zhao, Thomas Eric Gorsuch, Ross L. Lintelman
  • Patent number: 7181182
    Abstract: A smart antenna steering algorithm performs a self-monitored re-scan during a sustained use period after having selected a preferred antenna beam. During a sustained use period, a re-scan of the other antenna beams is not performed. The steering algorithm periodically monitors a quality metric of the ongoing radio link provided by the preferred antenna beam. The quality metric is based upon a signal quality metric and a link quality metric. If the quality metric drops below certain thresholds during the sustained use period, the steering algorithm either swaps the preferred antenna beam with an alternate antenna beam or initiates a re-scan of the available antenna beams for selecting a new preferred antenna beam.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: February 20, 2007
    Assignee: InterDigital Technology Corporation
    Inventors: Inhyok Cha, Zheng Zhao, Thomas Eric Gorsuch, Ross L. Lintelman
  • Publication number: 20070036353
    Abstract: The present invention relates to secret key generation and authentication methods that are based on joint randomness not shared by others (JRNSO), in which unique channel response between two communication terminals generates a secret key. Multiple network access points use a unique physical location of a receiving station to increase user data security. High data rate communication data is encrypted by generating a random key and a pseudo-random bit stream. A configurable interleaving is achieved by introduction of JRNSO bits to an encoder used for error-correction codes. Databases of user data are also protected by JRNSO-based key mechanisms. Additional random qualities are induced on the joint channel using MIMO eigen-beamforming, antenna array deflection, polarization selection, pattern deformation, and path selection by beamforming or time correlation. Gesturing induces randomness according to uniquely random patterns of a human user's arm movements inflected to the user device.
    Type: Application
    Filed: May 31, 2006
    Publication date: February 15, 2007
    Applicant: InterDigital Technology Corporation
    Inventors: Alexander Reznik, Debashish Purkayastha, Steven Goldberg, Robert Olesen, Marian Rudolf, Inhyok Cha, Alan Carlton, Yogendra Shah, Shamim Rahman, Rajat Mukherjee, Robert DiFazio, Gregory Sternberg, Leonid Kazakevich, Kazimierz Siwiak, Guodong Zhang, Tanbir Haque, Louis Guccione, Prabhakar Chitrapu, Akinlolu Kumoluyi, Alain Briancon
  • Publication number: 20060270343
    Abstract: A method and apparatus for selecting an antenna mapping in multiple-in/multiple-out (MIMO) enabled wireless communication networks. A candidate set of currently available antenna mappings is determined based upon measured long term channel conditions. An antenna mapping is selected from the candidate set, and the mapping is calibrated with a selected antenna mapping of a receiving wireless transmit/receive unit (WTRU). When the selected mappings are calibrated, packet data transmission begins. In an alternative embodiment, a calibration training frame (CTF) is used to calibrate multiple antenna mappings simultaneously or sequentially. Also disclosed are physical layer and medium access control layer frame formats for implementing antenna mapping selection according to the invention.
    Type: Application
    Filed: April 6, 2006
    Publication date: November 30, 2006
    Applicant: InterDigital Technology Corporation
    Inventors: Inhyok Cha, Eldad Zeira, Keith Baldwin
  • Publication number: 20060264184
    Abstract: A method and apparatus for selecting a beam combination of multiple-input multiple-output (MIMO) antennas are disclosed. A wireless transmit/receive unit (WTRUs) includes a plurality of antennas to generate a plurality of beams for supporting MIMO. At least one antenna is configured to generate multiple beams, such that various beam combinations can be produced and a desired beam combination selected for conducting wireless communication with another WTRU. A quality metric is measured with respect to each or subset of the possible beam combinations. A desired beam combination for MIMO transmission and reception is selected based on the quality metric measurements.
    Type: Application
    Filed: February 13, 2006
    Publication date: November 23, 2006
    Applicant: InterDigital Technology Corporation
    Inventors: Yingxue Li, Inhyok Cha, Jungwoo Lee
  • Publication number: 20060203789
    Abstract: An apparatus and a method for improving packet transmission and reducing latency in VoIP over WLAN using switched beam antennas having multiple directional antenna beams are disclosed. In an access point having a switched beam antenna, or other smart antenna system, the present invention extends the coverage area of an access point for authentication and association of a new WTRU, extends the access points coverage area during in session transmissions with a WTRU, and adjusts data rates. The method also controls Contention Period (CP)/Contention Free Period (CFP) timing amongst beams emanating from an access point having a switched beam antenna, or other smart antenna system. Fast diversity switching, frame level switching, lowered data rates, and scanning multiple directional antenna beams for the optimum transmission beam are disclosed to improve beam selection and packet transmission.
    Type: Application
    Filed: December 13, 2005
    Publication date: September 14, 2006
    Applicant: InterDigital Technology Corporation
    Inventors: Ana Iacono, Arty Chandra, Inhyok Cha, John Chen, Yingxue Li, James Otto
  • Publication number: 20060079220
    Abstract: A communications device with a switched beam antenna operates in a wireless local area network (WLAN) that includes a plurality of transmitters. The switched beam antenna generates a plurality of antenna beams. A method for operating the communications device includes receiving signals from the plurality of transmitters operating within the WLAN, identifying the received signals comprising medium access control (MAC) information, and determining a quality metric for each received signal comprising MAC information. A transmitter is selected based on the quality metrics. The antenna beams are scanned for receiving from the selected transmitter the signals comprising MAC information. A quality metric associated with each scanned antenna beam is determined. One of the scanned antenna beams is then selected for communicating with the selected transmitter based on the quality metrics.
    Type: Application
    Filed: September 16, 2005
    Publication date: April 13, 2006
    Applicant: InterDigital Technology Corporation
    Inventors: Inhyok Cha, Yingxue Li
  • Publication number: 20060073850
    Abstract: A method for steering a smart antenna in a wireless communication system begins by selecting a beam steering criterion. The antenna is switched to one of a plurality of measurement positions and link quality metrics are measured at each measurement position. The steering criterion are optimized based on the measured metrics, and the antenna is steered to the position providing the optimized metrics.
    Type: Application
    Filed: December 28, 2004
    Publication date: April 6, 2006
    Applicant: InterDigital Technology Corporation
    Inventors: Inhyok Cha, Ross Lintelman, Yingxue Li