Alireza Afrashteh from South Lake, TX, age 76

Us Patents

Systems And Methods For Increasing Base Station Capacity
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US Patent:

8031669, Oct 4, 2011
Filed:

Jul 29, 2005
Appl. No.:

11/192075
Inventors:

Alireza Afrashteh - Great Falls VA, US
Masoud Olfat - Clarksville MD, US
Douglas A. Hyslop - Vienna VA, US
Rajesh M. Gangadhar - Ashburn VA, US
Assignee:

Nextel Communications Inc. - Reston VA
International Classification:

H04W 4/00
US Classification:

370330, 370478
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.

Systems And Methods For Communicating Between Base Stations And Wireless Stations
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US Patent:

8081600, Dec 20, 2011
Filed:

Jul 29, 2005
Appl. No.:

11/192074
Inventors:

Alireza Afrashteh - Great Falls VA, US
Masoud Olfat - Clarksville MD, US
Douglas A. Hyslop - Vienna VA, US
Rajesh M. Gangadhar - Ashburn VA, US
Assignee:

Nextel Communications Inc. - Reston VA
International Classification:

G01R 31/08
US Classification:

370330, 370478
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.

Method, Apparatus And Computer-Readable Medium For Asymmetric Frequency Division Duplexing Operation
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US Patent:

8325670, Dec 4, 2012
Filed:

Mar 31, 2006
Appl. No.:

11/393889
Inventors:

Alireza Afrashteh - Great Falls VA, US
Masoud Olfat - Clarksville MD, US
Douglas A. Hyslop - Fairfax VA, US
Rajesh M. Gangadhar - Ashburn VA, US
Assignee:

Nextel Communications, Inc. - Reston VA
International Classification:

H04W 4/00
US Classification:

370330, 370322, 370329, 455450, 4554521
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.

Enhanced Coverage And Throughput Using Multiple Wireless Technologies
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US Patent:

8355747, Jan 15, 2013
Filed:

May 25, 2006
Appl. No.:

11/440000
Inventors:

Barry West - Alexandria VA, US
Alireza Afrashteh - Great Falls VA, US
Masoud Olfat - Clarksville MD, US
Douglas A. Hyslop - Vienna VA, US
Rajesh M. Gangadhar - Ashburn VA, US
Assignee:

Nextel Communications Inc. - Reston VA
International Classification:

H04M 1/00
US Classification:

4555521, 4554351, 4554352, 455436, 455443, 455448, 455561, 4555621
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.

One Button Push To Translate Languages Over A Wireless Cellular Radio
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US Patent:

20050144012, Jun 30, 2005
Filed:

Nov 4, 2004
Appl. No.:

10/980816
Inventors:

Alireza Afrashteh - Reston VA, US
David Chapman - Reston VA, US
Mar Tarres - New York NY, US
International Classification:

G10L011/00
US Classification:

704277000
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.

Method, Computer-Readable Medium, And Apparatus For Dynamic Resource Allocation Across Fdd And Tdd Systems
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US Patent:

20070248043, Oct 25, 2007
Filed:

Apr 20, 2006
Appl. No.:

11/407035
Inventors:

Alireza Afrashteh - Great Falls VA, US
Masoud Olfat - Calrksville MD, US
Douglas Hyslop - Fairfax VA, US
Rajesh Gangadhar - Ashburn VA, US
Assignee:

NEXTEL COMMUNICATIONS, INC. - Reston VA
International Classification:

H04Q 7/00
US Classification:

370329000, 370227000
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.

System And Method For Supporting Multiple Technologies In A Wireless Communication Cell
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US Patent:

20080108367, May 8, 2008
Filed:

Nov 8, 2006
Appl. No.:

11/594168
Inventors:

Alireza Afrashteh - Great Falls VA, US
Masoud Olfat - Clarksville MD, US
Douglas A. Hyslop - Vienna VA, US
Rajesh M. Gangadhar - Ashburn VA, US
Assignee:

Nextel Communications, Inc. - Reston VA
International Classification:

H04Q 7/20
H04M 1/00
US Classification:

4554522, 455561
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.

Adaptive Class Ab Amplifier For Tdma Wireless Communications Systems
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US Patent:

54266416, Jun 20, 1995
Filed:

Jan 28, 1994
Appl. No.:

8/187973
Inventors:

Alireza Afrashteh - Falls Church VA
Nelson R. Sollenberger - Tinton Falls NJ
Assignee:

Bell Communications Research, Inc. - Livingston NJ
International Classification:

H04B 104
US Classification:

370 953
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.