Santanu S Dutta

US Patent:

6381289, Apr 30, 2002

Filed:

Sep 1, 1998

Appl. No.:

09/145105

Inventors:

Santanu Dutta - Cary NC

Assignee:

Ericsson Inc. - Research Triangle Park NC

International Classification:

H03D 300

US Classification:

375335, 455426

Abstract:

A method of demodulating a communication signal is provided. The communication signal includes a plurality of pages with each page having a plurality of addresses and corresponding data packets. The demodulating method includes the steps of receiving the communication signal at a user terminal, identifying which of the plurality of pages are destined to the receiving user terminal, identifying which of the plurality of data packets within the identified page are destined to the receiving user terminal, and demodulating only the data packets identified as being destined to the receiving user terminal.

US Patent:

6407986, Jun 18, 2002

Filed:

Jan 20, 1999

Appl. No.:

09/233067

Inventors:

Santanu Dutta - Cedar Rapids IA

Assignee:

Mobile Satellite Ventures LP - Reston VA

International Classification:

H04B 7212

US Classification:

370280, 370321, 370337, 370347, 370350, 370465

Abstract:

A method of communicating on at least one channel group of a communication system provides improved data transfer efficiencies over conventional systems by using discrete transfer rates. The channel group is includes at least one forward channel for channeling data transmitted from a central station to a plurality of terminals. At least one return channel is included for channeling transmissions by any of the plurality of terminals to the central station. Changes in the discrete data transfer rate are optionally accompanied by a change in a slot timing rate based on a frame transmission rate used over the forward channel. The method also allows the assignment of a predetermined number of return channel slots for a transmit frame for at least one combination of forward and return channels having prescribed forward and return data rates.

US Patent:

6463040, Oct 8, 2002

Filed:

Apr 28, 1999

Appl. No.:

09/300423

Inventors:

Santanu Dutta - Cedar Rapids IA

Assignee:

Mobile Satellite Ventures, LM - Reston VA

International Classification:

H04B 7212

US Classification:

370280, 370321, 370337, 370347, 370465, 370470

Abstract:

Data transfer efficiencies of a frequency division and/or time division multiple access (FDMA/TDMA) communication methods are improved over prior art methods by communicating over a channel group of a comunication system. A central station transmits to a number of terminals over a forward channel, and transmissions by at least one of the terminals to the central station occur over a return channel of the channel group. The improved methods include the step of transmitting by the at least one of the plurality of terminals at least one superframe to the central station at one of a plurality of data rates over one of a plurality of return channels using a corresponding one of a plurality of data frames having lengths responsive to the one of the plurality of data rates. The methods may also include the step of formatting said transmission superframe comprising a plurality of frames by removing network management information which is not time critical from substantially all of the plurality of frames.

US Patent:

6515976, Feb 4, 2003

Filed:

Apr 6, 1998

Appl. No.:

09/055491

Inventors:

Paul W. Dent - Pittsboro NC
Santanu Dutta - Research Triangle Park NC

Assignee:

Ericsson Inc. - Research Triangle Park NC

International Classification:

H04J 300

US Classification:

370336, 330350, 375324, 455574, 340 732, 340 745

Abstract:

A method and apparatus for demodulating a communication signal transmitted at a first rate is provided, wherein the communication signal includes a plurality of addresses and corresponding data packets. The demodulating method includes the steps of receiving the communication signal at a user terminal, identifying which of the plurality of data packets are destined to the receiving user terminal, and demodulating, at a second rate less than the first rate, only the data packets identified as being destined to the receiving user terminal.

US Patent:

6587443, Jul 1, 2003

Filed:

Apr 28, 1999

Appl. No.:

09/300422

Inventors:

Santanu Dutta - Cedar Rapids IA

Assignee:

Mobile Satellite Ventures, LP - Reston MA

International Classification:

H04B 7212

US Classification:

370322, 370348, 370443

Abstract:

Data transfer efficiencies of a frequency division and/or time division multiple access (FDMA/TDMA) communication systems are improved over prior art systems by distributing signalling and messaging activities over all return channels of a channel group, by varying forward to return channel data rate ratios, and by reducing message transport delays with respect to prior art communication systems, based on message traffic over such channel group. Return channels of a defined channel group are time division controlled and are generic to operate either in a signalling mode or in a messaging mode. Data rates for the forward channel and the return channels may be selected from predefined combinations of forward and return channel data rates. Message transport delays are reduced over prior art delay periods by reducing the frame lengths of data frames transmitted at a specified frame rate over the forward channel and by transmitting network management data other than time-critical data reception results and time slot allocations periodically at a superframe rate which is less than the frame rate.

US Patent:

6639898, Oct 28, 2003

Filed:

May 25, 1999

Appl. No.:

09/318266

Inventors:

Santanu Dutta - Cedar Rapids IA
David W. Best - Marion IA
Dennis W. Sutherland - Marion IA
Thomas A. Trebs - Hiawatha IA

Assignee:

Motient Communications, Inc. - Reston VA

International Classification:

H04J 106

US Classification:

370238, 370316, 370349, 370401

Abstract:

A packet switched multi-mode mobile communication network and fixed and mobile devices for use therewith are disclosed. Each of the mobile vehicle equipment and a base station packet switch are coupled to respective data terminal equipment which generates packet data messages. The packet data messages have message characteristics associated therewith. Each of the mobile vehicle equipment and the base station packet switch have an intelligent switching node incorporated therein for selecting which of a plurality of radio frequency transmission paths to use in transmitting the packet data message to the other of the mobile vehicle equipment and the base station packet switch. Each of the plurality of radio frequency transmission paths has transmission path characteristics associated therewith. The intelligent switching nodes select the radio frequency transmission path as a function of the message characteristics of the packet data message and as a function of the transmission path characteristics of the plurality of radio frequency transmission paths.

US Patent:

6879829, Apr 12, 2005

Filed:

Apr 20, 2004

Appl. No.:

10/828378

Inventors:

Santanu Dutta - Cary NC, US
Peter D. Karabinis - Cary NC, US

Assignee:

Mobile Satellite Ventures, LP - Reston VA

International Classification:

H04Q007/20

US Classification:

455436, 455 121, 455438, 455428

Abstract:

A satellite communications system includes a satellite that is configured to wirelessly communicate with radioterminals in a satellite coverage area over a satellite frequency band, and an ancillary terrestrial component that is configured to wirelessly communicate with radioterminals in the satellite coverage area over at least some of the satellite frequency band, to thereby terrestrially reuse at least some of the satellite frequency band. Wireless communications with a radioterminal are handed over from the ancillary terrestrial component to the satellite if the radioterminal transmit power exceeds a threshold, and a received satellite signal quality exceeds a threshold, even though the radioterminal is able to wirelessly communicate with the ancillary terrestrial component. Downlink wireless radiation that is received at the radioterminal from a satellite may be monitored to determine potential interference created by the uplink radiation of the radioterminal due to the terrestrial reuse of at least some of the satellite frequency band.

US Patent:

7203490, Apr 10, 2007

Filed:

Mar 8, 2004

Appl. No.:

10/795620

Inventors:

Peter D. Karabinis - Cary NC, US
Boris Bogatin - Huntingdon Valley PA, US
Brian M. Deobald - Bethesda MD, US
Santanu Dutta - Cary NC, US

Assignee:

ATC Technologies, LLC - Reston VA

International Classification:

H04Q 7/20
H04B 7/185
H04M 1/00

US Classification:

455428, 455561, 455 133

Abstract:

A satellite is used to route push-to-send messages among terrestrial base stations. Reduced push-to-send delays thereby may be provided, when a source push-to-send radioterminal is widely separated from a destination push-to-send radioterminal. Satellite routing only may be used when the source push-to-send radioterminal and the destination push-to-send radioterminal are not communicating with a single terrestrial base station or with a group of terrestrial base stations that are proximate one another. A destination base station that is communicating with the destination push-to-send radioterminal may be determined at the satellite, at a satellite gateway and/or at a central server.