Chandra Prakash Joshi Deceased10833 Outpost Dr, Gaithersburg, MD 20878

6353738, Mar 5, 2002

Feb 11, 1999

09/247845

Chandra Joshi - Gaithersburg MD
Anthony Noerpel - Lovettsville VA
Chi-Jiun Su - Derwood MD

Hughes Electronics Corporation - El Segundo CA

H04Q 720

455427, 455428, 455430, 455445, 455450, 455515

An MSAT system is provided which optimizes satellite resources when implementing a single-hop TtT call. The system allocates satellite channels and signaling channels for a single-hop TtT call to the participating terminals at an early stage during the call set-up procedure such that only a single pair of satellite channels are assigned to each of the terminals for call establishment and for use during the call, as opposed to two pairs of satellite channels. A test message for signaling channel (e. g. , TTCH) validation is transmitted from the network (e. g. , from a gateway station controller) to each of the terminals.

6438386, Aug 20, 2002

Jul 13, 1998

09/115095

Chandra Joshi - Gaithersburg MD
Anthony R. Noerpel - Lovettsville VA
Gerard Stelzer - Frederick MD
Mohammad Soleimani - Rockville MD
Prabir Datta - Delhi, IN
Xiaoping He - Germantown MD

Hughes Electronics Corporation - El Segundo CA

H04B 726

455515, 455450, 455455

An approach for immediate channel assignment in a wireless communications system involves receiving a channel request message from a wireless transceiver, the channel request message including a dialed party number; forming an immediate assignment message including a channel assignment; transmitting the immediate assignment message to the wireless transceiver; and establishing a communications channel between the wireless transceiver and a called party by establishing a channel between the wireless transceiver and the called party.

6516065, Feb 4, 2003

Feb 11, 1999

09/247848

Chandra Joshi - Gaithersburg MD
Anthony Noerpel - Lovettsville VA
Chi-Jiun Su - Derwood MD

Hughes Electronics Corporation - El Segundo CA

H04K 100

380270

A mobile satellite communication system is provided to control the transfer of a terminal for a single-hop call from at least one of a clear mode and a ciphered mode with respect to a gateway station to a ciphered mode with respect to a satellite link connecting the terminal with another terminal for a single-hop, terminal-to-terminal call using a cipher key and an encryption algorithm common to the terminal and the other terminal. Frame number offset data, which indicates a mapping delay between received and transmitted time slots at the satellite, is provided to both terminals in a terminal-to-terminal call for ciphering synchronization.

6650895, Nov 18, 2003

Nov 23, 1999

09/447696

Channasandra Ravishankar - Germantown MD
David Roos - Boyds MD
Anthony Noerpel - Lovettsville VA
Chandra Joshi - Gaithersburg MD
James Hobza - Carlsbad CA
Prabir Datta - New Delhi, IN
Yi Chen - Gaithersburg MD

Hughes Electronics Corporation - El Segundo CA

H04Q 720

4554221, 455560, 455564, 455427

A system and a methodology to improve the end-user quality of service both in terms of response time and reliability for the transport of in-call DTMF signals in wireless systems, particularly in geostationary mobile satellite systems. The methodology encompasses several techniques to provide acceptable end-to-end quality of service for DTMF. A technique is applicable for transport of DTMF in the wireless subscriber to network direction, where DTMF digits are carried in the form of an out-band message. The central part of the technique is to allow multiple key presses in the same message, thereby increasing efficiency and throughput in long-delay environment. Another technique utilizes the vocoders functionality to carry DTMF in-band, thereby reducing system complexity. The scheme makes the use of an integrated DTMF detector which can classify a given frame of signal into several classes so that the DTMF encoded packet can carry a unique pattern across the air-interface to the voice decoder at AT, which is capable of identifying the pattern. Another technique pertains to the use of a message based DTMF transport between two-ATs on a separate logical channel with a unique Service Access point Identifier (SAPI) providing guaranteed service for DTMF transport in an AT-AT call.

6249677, Jun 19, 2001

Feb 11, 1999

9/247849

Anthony Noerpel - Lovettsville VA
Chandra Joshi - Gaithersburg MD
Stephanie Demers - Rockville MD

Hughes Electronics Corporation - El Segundo CA

H04Q 720

455427

An apparatus and method, for use with the satellite-based communications network, for improving the reliability and speed at which communication between a user terminal and the network is established. The apparatus and method arranges data of a channel request message transmitted from a user terminal to a satellite in the satellite-based network to insure that the most critical data for establishing communication between the user terminal and the satellite-based network is received at the satellite during the appropriate receiving time frame window. The channel request message includes a first data group necessary for establishing a communication link for which information is transmitted between the apparatus and the network, and a second data group including information for decreasing the amount time necessary to establish the communication link. The first data group is positioned at the center of the channel request message, with portions of the second data group at opposite ends of the channel request message. The time at which the user terminal transmits the channel request message is set based on a location of the apparatus within a spot beam, to take into account the appropriate propagation delay time for the message to travel from the apparatus to the satellite in the network, thus assuring that at least the first data group of the channel request message is received at the satellite during an appropriate receiving time frame window.

6289482, Sep 11, 2001

Jul 13, 1998

9/115099

Chandra Joshi - Gaithersburg MD
Anthony Noerpel - Lovettsville VA
Xiaoping He - Germantown MD
Prabir Datta - Delhi, IN

Hughes Electronics Corporation - El Segundo CA

G08C 2502
G06F 1100
H04L 100

714748

An approach for error flow control in a communications system involves receiving a plurality of frames of data; determining in said plurality of frames of data, two or more contiguous defective frames of data, the two or more contiguous defective frames of data being followed by at least one frame of data in said plurality of frames that is not defective; forming a group reject message indicative of a range of the two or more contiguous defective frames; transmitting the group reject message; and receiving replacement frames, the replacement frames corresponding to the two or more contiguous defective frames, wherein said at least one frame that is not defective is not received again in response to the group reject message.

6233451, May 15, 2001

Jul 13, 1998

9/115096

Anthony Noerpel - Lovettsville VA
Chandra Joshi - Gaithersburg MD
Michael Parr - Hermosa Beach CA
Zhengping Gao - Gaithersburg MD
Stephanie Demers - Rockville MD

Hughes Electronics Corporation - El Segundo CA

H04Q 720

455427

An access terminal for initiating spot beam selection in a satellite communication system, in which the access terminal includes a receiver for measuring the received signal strength (RSS) of a multiplicity of radio frequency communication spot beam links. The access terminal is further provided with a microcontroller for comparing the received signal strengths from each of the multiplicity of spot beams to initiate information communication via a communication channel of the satellite communication system. In a described embodiment, the controller of the access terminal compares seven spot beam links to determine whether to initiate information communication with one of the seven spot beams received. Additionally, a memory coupled to the controller of the access terminal is used for storing spot beam identification information including the spot beam links assigned to the access terminal via the satellite communication system. The selection procedure employed by the system and method described facilitate a rapid selection of an appropriate spot beam identified from the multiplicity of radio frequency spot beam links received at a mobile access terminal.

6278876, Aug 21, 2001

Jul 13, 1998

9/115098

Chandra Joshi - Gaithersburg MD
Anthony Noerpel - Lovettsville VA
Neeraj Tewari - North Potomac MD
Gerard Stelzer - Frederick MD
David Roos - Boyds MD
Chi-Jiun Su - Derwood MD

Hughes Electronics Corporation - El Segundo CA

H04Q 720

455427

A system and method for implementing single hop space segment terminal to terminal connections. The system includes a satellite-based radio frequency (RF) communication link for conveying multiple communication channels over the space segment via one or more spot beams. A terrestrial supervisory transceiver such as a gateway station is provided in communication with the satellite-based communication link. Mobile hand-held terminals (HHTs), herein first and second access terminals, may be located within one or more of the spot beams to communicate with one another via a single hop connection through a satellite of the system. A switch is provided for communication switching with the satellite of the system for the multiple communication channels to couple the first access terminal and the second access terminal over the space segment via one or more of the spot beams. The terrestrial supervisory transceiver or gateway is provided in communication with the satellite switch via the satellite-based communication link for implementing the single hop space segment terminal to terminal connection.