Patents by Inventor Alireza Afrashteh

Alireza Afrashteh 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: 8355747
    Abstract: Systems and methods for dual wireless communication technology communications are provided. A mobile station communicates with two transceivers of a base site, where each transceiver operates according to a different wireless communication technology. The mobile station can communicate uplink and downlink control information with a first transceiver of the base site while also communicating uplink and downlink data with a second transceiver. Alternatively, the mobile station may transmit uplink transmissions only to a first transceiver and only receive downlink transmissions from a second transceiver.
    Type: Grant
    Filed: May 25, 2006
    Date of Patent: January 15, 2013
    Assignee: Nextel Communications Inc.
    Inventors: Barry West, Alireza Afrashteh, Masoud Olfat, Douglas A. Hyslop, Rajesh M. Gangadhar
  • Patent number: 8325670
    Abstract: A method, apparatus, and computer-readable medium for performing asymmetric frequency division duplexing (FDD) are provided. The method includes allocating a first bandwidth for an uplink portion of an FDD data transmission; and allocating a second bandwidth for a downlink portion of the FDD data transmission; wherein the first bandwidth and the second bandwidth have different sizes.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: December 4, 2012
    Assignee: Nextel Communications, Inc.
    Inventors: Alireza Afrashteh, Masoud Olfat, Douglas A. Hyslop, Rajesh M. Gangadhar
  • Patent number: 8081600
    Abstract: Systems and methods for communicating between a wireless station and a base station are provided. A base station can allocate both a TDD channel and an FDD channel pair for communicating with a wireless station. The base station can transmit and receive unicast messages using the time slots of the TDD channel or can transmit multicast messages over all time slots of the TDD channel.
    Type: Grant
    Filed: July 29, 2005
    Date of Patent: December 20, 2011
    Assignee: Nextel Communications Inc.
    Inventors: Alireza Afrashteh, Masoud Olfat, Douglas A. Hyslop, Rajesh M. Gangadhar
  • Patent number: 8031669
    Abstract: Systems and methods for enhancing the capacity of base stations are provided. A base station can operate in a time division duplex mode within a first frequency band. When a second frequency band is acquired for the base station's geographic region, a duplexer can be added to the base station. The base station can then operate in a frequency division duplex mode, where the first frequency band is used for base station downlink transmissions and the second frequency band is used for uplink transmissions.
    Type: Grant
    Filed: July 29, 2005
    Date of Patent: October 4, 2011
    Assignee: Nextel Communications Inc.
    Inventors: Alireza Afrashteh, Masoud Olfat, Douglas A. Hyslop, Rajesh M. Gangadhar
  • Publication number: 20080108367
    Abstract: Systems and methods for supporting multiple wireless communication technologies within a cell are provided. A base station can transmit a second wireless communication technology in a smaller coverage than the coverage of the first wireless communication technology, thereby producing an underlay-overlay cell radiation pattern. Whether a mobile station communicates with the base station using the first or second wireless communication technology can be based on a comparison of signal quality measures for the mobile station, or any other performance metric with a fixed or dynamic threshold.
    Type: Application
    Filed: November 8, 2006
    Publication date: May 8, 2008
    Applicant: Nextel Communications, Inc.
    Inventors: Alireza Afrashteh, Masoud Olfat, Douglas A. Hyslop, Rajesh M. Gangadhar
  • Publication number: 20070248043
    Abstract: A method, computer-readable medium, and apparatus for dynamically assigning radio resources between a frequency division duplexing (FDD) carrier and a time division duplexing (TDD) carrier is provided. The method includes monitoring radio frequency conditions and traffic load of the FDD and TDD carriers; allocating a resource assignment for a downlink on the FDD carrier or the TDD carrier, based upon the radio frequency conditions or the traffic load of the FDD and TDD carriers; and allocating a resource assignment for an uplink on the FDD carrier or the TDD carrier, based upon the radio frequency conditions or the traffic load of the FDD and TDD carriers.
    Type: Application
    Filed: April 20, 2006
    Publication date: October 25, 2007
    Applicant: NEXTEL COMMUNICATIONS, INC.
    Inventors: Alireza Afrashteh, Masoud Olfat, Douglas Hyslop, Rajesh Gangadhar
  • Publication number: 20070230414
    Abstract: A method, apparatus, and computer-readable medium for performing asymmetric frequency division duplexing (FDD) are provided. The method includes allocating a first bandwidth for an uplink portion of an FDD data transmission; and allocating a second bandwidth for a downlink portion of the FDD data transmission; wherein the first bandwidth and the second bandwidth have different sizes.
    Type: Application
    Filed: March 31, 2006
    Publication date: October 4, 2007
    Applicant: NEXTEL COMMUNICATIONS, INC.
    Inventors: Alireza Afrashteh, Masoud Olfat, Douglas Hyslop, Rajesh Gangadhar
  • Publication number: 20070025291
    Abstract: Systems and methods for enhancing the capacity of base stations are provided. A base station can operate in a time division duplex mode within a first frequency band. When a second frequency band is acquired for the base station's geographic region, a duplexer can be added to the base station. The base station can then operate in a frequency division duplex mode, where the first frequency band is used for base station downlink transmissions and the second frequency band is used for uplink transmissions.
    Type: Application
    Filed: July 29, 2005
    Publication date: February 1, 2007
    Applicant: NEXTEL COMMUNICATIONS, INC.
    Inventors: Alireza Afrashteh, Masoud Olfat, Douglas Hyslop, Rajesh Gangadhar
  • Publication number: 20070025290
    Abstract: Systems and methods for communicating between a wireless station and a base station are provided. A base station can allocate both a TDD channel and an FDD channel pair for communicating with a wireless station. The base station can transmit and receive unicast messages using the time slots of the TDD channel or can transmit multicast messages over all time slots of the TDD channel.
    Type: Application
    Filed: July 29, 2005
    Publication date: February 1, 2007
    Applicant: NEXTEL COMMUNICATIONS, INC.
    Inventors: Alireza Afrashteh, Masoud Olfat, Douglas Hyslop, Rajesh Gangadhar
  • Publication number: 20050144012
    Abstract: A system having a plurality of communication devices, at least one of which comprises a control device, a half duplex communication network to transmit data between the plurality of communication devices, and a translation engine to translate voice communications spoken into a first one of the communication devices into at least one other language, wherein when the control device of one of the communication devices is activated, the corresponding communication device secures a floor control of the network, and while the floor control is secured, the communication device communicates with the translation engine such that words spoken into the communication device are translated, and the network transmits the translated communications to selected ones of the plurality of communication devices.
    Type: Application
    Filed: November 4, 2004
    Publication date: June 30, 2005
    Inventors: Alireza Afrashteh, David Chapman, Mar Tarres
  • Patent number: 5426641
    Abstract: In a TDM/TDMA portable radio communications system, the modulated RF signal transmitted by a portable handset unit is amplified for uplink transmission to a port by an adaptive class AB power amplifier. A class AB amplifier provides the necessary amplification for the low power levels to be output by the portable units, but must be biased just slightly "on" with no signal input for required maximum efficiency and linearity. In order to maintain the amplifier at a proper bias level over changing temperature conditions and free from the effects of device aging and device-to-device variations, the drain current of the amplifier is monitored each frame outside the burst interval in which the portable is transmitting and thus when no signal is present at its input. The drain current is then controlled by adjusting the gate voltage to compensate for any variations.
    Type: Grant
    Filed: January 28, 1994
    Date of Patent: June 20, 1995
    Assignee: Bell Communications Research, Inc.
    Inventors: Alireza Afrashteh, Nelson R. Sollenberger
  • Patent number: 4603926
    Abstract: Two microstrip transmission line substrates are mounted face-to-face at a fixed separation determined by mating connector halves which provide microstrip to coaxial transmission line transitions. Each connector half includes a body portion, a stand-off portion and a coaxial connector portion.
    Type: Grant
    Filed: December 29, 1983
    Date of Patent: August 5, 1986
    Assignee: RCA Corporation
    Inventors: Gerald H. Nesbit, Alireza Afrashteh
  • Patent number: 4471346
    Abstract: A portable, battery powered smoke detector in which the operative components are compactly and efficiently arranged in such a manner that they may be housed in a pocket-sized casing approximating the shape and size of a cigarette package. A further embodiment shows an efficiently organized arrangement of the smoke detector components in a telephone set.
    Type: Grant
    Filed: June 2, 1981
    Date of Patent: September 11, 1984
    Assignee: Eberhard Faber, Inc.
    Inventors: John E. Nelson, Alireza Afrashteh, Umid R. Nejib