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Channasandra S Ravishankar

from Clarksburg, MD
Age ~61
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Also known as:
Channasandra Sampangiram Ravishankar, Channasand S Ravishankar, Channasandra Ravishanka, Channasand S Ravishan, R Ravishankar, Channasandra R, R Ravishan
Phone and address:
23604 Lefty Ln, Clarksburg, MD 20871
Related to:
Tejash R Patel, 52Jayshri Ravishankar, 53Veda RavishankarVimal N Patel, 42Gitaben Patel, 59Jaymish N Patel, 38Amita T Patel, 46Navinchandra N Patel, 73Jayanti J Patel, 82Jayshri R Patel, 53
Connected to:
Dhanya Ravishankar, 47Harshitha Ravishankar, 34Krishnan Ravishankar, 47Rashmi M Ravishankar, 39Viswanatha Ravishankar, 58Norman Ravitch, 88Jolene K Ravithis, 62Alex Ravitsky, 70Alexandra Ravitsky, 71Daniel L Ravitz, 34

Channasandra Ravishankar Phones & Addresses

  • 23604 Lefty Ln, Clarksburg, MD 20871
  • 12304 Milestone Manor Ct, Germantown, MD 20876 (301) 972-9272
  • Lafayette, IN

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Channasandra Ravishankar Photo 1

Channasandra Ravishankar

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Publications

Us Patents

Facsimile Call Success Rates In Long Delay Environments

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US Patent:
6411689, Jun 25, 2002
Filed:
Feb 11, 1999
Appl. No.:
09/247846
Inventors:
Junhao Shi - Gaithersburg MD
Brandt Springman - Washington DC
Santharam Gurumani - Gaithersburg MD
Channasandra S. Ravishankar - Germantown MD
Sundari Balachandran - Rockville MD
Assignee:
Hughes Electronics Corporation - El Segundo CA
International Classification:
H04M 1100
US Classification:
37910017, 37910005, 37910009
Abstract:
A facsimile transmission relay apparatus, referred to as an Intelligent Facsimile Relay (IFR) for improving call success rates in long delay environment such as terrestrial cellular, fixed wireless, and geostationary mobile satellite systems and the like. A first bi-directional telecommunications interface is provided for receiving facsimile signals from a transmitting facsimile device via a first network such as a Public Switch Telephone Network (PSTN). A buffer memory is used by the IFR for storing the facsimile signal, and a second bi-directional telecommunications interface retransmits the facsimile signal via the second network, e. g. , a wireless network, to a receiving facsimile device to avoid signal collisions between the devices. An information processor is coupled to the second interface for monitoring messages from the receiving facsimile device and for generating messages to the receiving facsimile device to maintain communications integrity with the transmitting facsimile device via the first and second networks.

Facsimile Call Success Rates In Long Delay And Impaired Channel Environments Without Collision Detection

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US Patent:
6603577, Aug 5, 2003
Filed:
Nov 16, 1999
Appl. No.:
09/440744
Inventors:
Channasandra S. Ravishankar - Germantown MD
Brandt Springman - Washington DC
Sundari Balachandran - Rockville MD
Junhao Shi - Gaithersburg MD
Assignee:
Hughes Electronics Corporation - El Segundo CA
International Classification:
H04N 100
US Classification:
358434, 358400, 358405, 358406, 358407, 37910017, 37910009, 37910006
Abstract:
A facsimile transmission relay apparatus, referred to as an Intelligent Facsimile Relay (IFR) for improving call success rates in long delay environment such as terrestrial cellular, fixed wireless, and geostationary mobile satellite systems and the like. A first bi-directional telecommunications interface is provided for receiving facsimile signals from a transmitting facsimile device via a first network such as a Public Switch Telephone Network (PSTN). A buffer memory is used by the IFR for storing the facsimile signal, and a second bi-directional telecommunications interface retransmits the facsimile signal via the second network. An information processor is coupled to the second interface for monitoring messages from the receiving facsimile device and for generating messages to the receiving facsimile device to maintain communications integrity with the transmitting facsimile device via the networks using selective blocking of retransmitted commands for less sensitivity to the channel errors present in wireless applications, without the need for signal collision detection. The ultimate objective of the IFR design is to prevent call failures due to long delays and/or channel impairments by monitoring, buffering, relaying, replacing, and manipulating ITU-T T. 30 signals as well as generating ITU-T T.

In-Call Dtmf Transport For Geostationary Mobile Satellite Communication System

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US Patent:
6650895, Nov 18, 2003
Filed:
Nov 23, 1999
Appl. No.:
09/447696
Inventors:
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
Assignee:
Hughes Electronics Corporation - El Segundo CA
International Classification:
H04Q 720
US Classification:
4554221, 455560, 455564, 455427
Abstract:
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.

Mac Layer Protocol For A Satellite Based Packet Switched Services

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US Patent:
6778509, Aug 17, 2004
Filed:
Nov 16, 2000
Appl. No.:
09/714788
Inventors:
Channasandra Ravishankar - Germantown MD
Anthony Noerpel - Lovettsville VA
Mahesh Kamath - New Delhi, IN
Abheek Saha - New Delhi, IN
James Hobza - Carlsbad CA
Assignee:
Hughes Electronics Corporation - El Segundo CA
International Classification:
H04B 7212
US Classification:
370322, 370348
Abstract:
An approach for minimizing response times in transporting traffic over a packet radio communication system is disclosed. A terminal transmits a packet resource request message that specifies user terminal information using a contention channel according to a prescribed protocol. A gateway station receives the packet resource request message and transmits an assignment message that specifies a channel assignment based upon the user terminal information, wherein the terminal is configured to transmit the packets over a channel is based on the channel assignment. This approach has particular applicability to a satellite communication system.

System And Method For Providing Contention Channel Organization For Broadband Satellite Access In A Communications Network

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US Patent:
6980800, Dec 27, 2005
Filed:
Feb 12, 2002
Appl. No.:
10/074759
Inventors:
Anthony Noerpel - Lovettsville MD, US
Channasandra Ravishankar - Germantown MD, US
Xiaoping He - Frederick MD, US
Abheek Saha - New Delhi, IN
Assignee:
Hughes Network Systems - El Segundo CA
International Classification:
H04Q007/20
H04B007/212
US Classification:
455434, 455450, 4554521, 4554522, 370330, 370348, 370461, 370462, 370345, 370337
Abstract:
Two types of contention channels are used to accommodate broadband packet data in a satellite communication network. A first contention channel is used by unsynchronized user terminals to access the system and request a traffic channel. The first contention channel is of a sufficient duration to accommodate a RACH message, as well as the timing uncertainty between user terminals within a given spot beam. A second contention channel is shorter in duration than the first contention channel, and is narrowband, so that more than one second contention channel may be transmitted within the bandwidth of the broadband traffic channels. The second contention channels are used by synchronized user terminals for transmitting packet RACH, or PRACH, messages. The more efficient nature of the PRACH channels accommodates the increased overhead associated with bursty packet data, without the capacity cost of the longer duration RACH channel.

System And Method For Providing Real-Time And Non-Real-Time Services Over A Communications System

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US Patent:
7580424, Aug 25, 2009
Filed:
Sep 17, 2002
Appl. No.:
10/245196
Inventors:
Channasandra Ravishankar - Germantown MD, US
Abheek Saha - New Delhi, IN
Saurabh Garg - Tampere, FI
Michael Darcy - Griesheim, DE
Assignee:
Hughes Network System, LLC - Germantown MD
International Classification:
H04J 3/16
H04W 72/00
US Classification:
370468, 4554522
Abstract:
A method, system, and computer program product for providing communications services, including determining a type of communications service present in a communications session based on quality of service parameters assigned for the communications session; and adjusting the quality of service parameters based a different type of communications service requested. The types of communications services include real-time and non-real-time communications services.

Leased Line Optimization And Voice Quality Improvement In Bandwidth Constrained Communication Systems

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US Patent:
20010000137, Apr 5, 2001
Filed:
Dec 4, 2000
Appl. No.:
09/728745
Inventors:
Channasandra Ravishankar - Germantown MD, US
Mohammad Soleimani - Rockville MD, US
Assignee:
Hughes Electronics Corporation
International Classification:
H04B014/04
US Classification:
370/527000, 375/253000
Abstract:
The present invention is embodied in a method an apparatus for reducing the number of leased Elines needed to backhaul communication traffic in a satellite communication situation. The present invention receives and decompressed a satellite signal. A copy of the compressed signal is then encoded into the least significant bits (LSBs) of the decompressed signal. The decompressed signal having the embedded information may be routed to an international PSTN network over leased communications lines. However, the compressed information is extracted from the decompressed signal and sent across the Elines, thereby conserving communication bandwidth and reducing the number of leased lines required. After passing through the Elines the information is decompressed and connected to the international PSTN network. Alternatively, the decompressed signal having the embedded information may be distributed to local PSTN networks, which interpret decompressed signals. The degradation in voice quality of the decompressed signal due to the embedding of the compressed information in negligible.

System And Method For Mobility Management For A Satellite Based Packet Data System

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US Patent:
20020052180, May 2, 2002
Filed:
Aug 7, 2001
Appl. No.:
09/923837
Inventors:
Channasandra Ravishankar - Germantown MD, US
Saurabh Garg - Uttar Pradesh, IN
Trevor Eagling - Frederick MD, US
Mike Darcy - Potomac MD, US
Assignee:
HUGHES ELECTRONICS
International Classification:
H04B007/185
US Classification:
455/012100, 455/445000, 455/456000, 455/427000
Abstract:
In a medium earth orbit (MEO) satellite system, an embodiment of the present invention employs a system and method for administering mobility management issues for mobile terminals, via a network of base station controllers. The mobility management issues, for example, paging, routing, and handover of communication signals are administered between the base station systems without having to be routed through the serving general packet radio service support node (SGSN).
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Channasandra S Ravishankar from Clarksburg, MD, age ~61 Get Report