Patents by Inventor Chandra S. Bontu

Chandra S. Bontu 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: 7302251
    Abstract: A wireless network includes wireless access systems for communicating with mobile stations. At least one of the wireless access systems is capable of communicating with multiple types of mobile stations. One type of mobile station communicates according to the Enhanced General Packet Radio Service (EGPRS) protocol, while another type of mobile station communicates according to the GSM/EDGE Radio Access Network (GERAN) protocol. The wireless access system includes control logic to select one of plural types of protocol stacks to use for communications over an air link with the different types of mobile stations. In response to an indicator of a first type, the wireless access system selects a first protocol stack, and in response to an indicator of a second type, the wireless access system selects a second protocol stack.
    Type: Grant
    Filed: August 30, 2001
    Date of Patent: November 27, 2007
    Assignee: Nortel Networks Limited
    Inventors: Peter A. Barany, Chandra S. Bontu, Shamim Akbar Rahman
  • Patent number: 7126939
    Abstract: A communications system includes a wireless access network that is coupled to a packet-based data network. Packet-based calls may be established between a mobile station coupled to the wireless access network and a network endpoint coupled to the data network. For efficient call setup and call release, call control signaling, such as Session Initiation Protocol (SIP) messages and Resource Reservation Protocol (RSVP) messages, are carried in traffic channels over the wireless access network.
    Type: Grant
    Filed: December 15, 2000
    Date of Patent: October 24, 2006
    Assignee: Nortel Networks Limited
    Inventors: Peter A. Barany, Chandra S. Bontu, Shamim Akbar Rahman
  • Patent number: 7068623
    Abstract: A mobile communications system includes a radio access network, such as an Enhanced General Packet Radio Service (EGPRS) network, in which mobile stations are able to enter into a discontinuous transmission (DTX) mode. During DTX mode of a first mobile station that is allocated a channel portion (e.g., a time slot of a frame), the radio access network is able to multiplex traffic from another mobile station onto the same channel portion. A mechanism is provided to enable the first mobile station to send a request for re-allocation of the channel portion. The request includes a Real-Time FastAssociated Control Channel (RTFACCH) resource request message (RTRRM). In response to the RTRRM, the radio access network sends an RTFACCH resource assignment message (RTUAM).
    Type: Grant
    Filed: November 17, 2000
    Date of Patent: June 27, 2006
    Assignee: Nortel Networks Limited
    Inventors: Peter A. Barany, Chandra S. Bontu, Shamim Akbar Rahman
  • Patent number: 6463073
    Abstract: The invention is a novel slot structure and method of transmitting data at a controllable power level. The slot comprises a header, a DATA field adjacent the header and a ramp interval adjacent the DATA field. The method consists of transmitting the entire slot at a sufficiently high power when the DATA field is occupied by data traffic or control information but to lower the power during transmission of the DATA field when the slot is a null slot. In the latter case, a gradual decrease of the transmitted power is effected during the first few symbols of the DATA field, whereas the power is brought back to a higher level during the ramp interval. The new power level may be higher or lower than the initial power level, depending on the destination mobile unit associated with the following slot.
    Type: Grant
    Filed: December 21, 1998
    Date of Patent: October 8, 2002
    Assignee: Nortel Networks Limited
    Inventors: Chandra S. Bontu, Shavantha Kularatna, Shamim A. Rahman, Yonghai Gu, Peter Barany
  • Patent number: 6445745
    Abstract: A method for phase encoding DPSK and N-PSK which maintains phase continuity and which does not require any reference symbols when using N-PSK. A sequence of known DPSK phases are encoded with respect to an initial phase. The N-PSK phases are then all offset by this same initial phase. The known DPSK phases can be used at a receiver to determine a sum consisting of the initial phase and any further phase shift introduced by the channel, and this sum is used to decode the unknown N-PSK phases. The method is more generally applicable to any case where a switch between a phase encoding method which requires an absolute phase reference and a phase encoding method which does not have an absolute phase reference is to be implemented on a single carrier or channel.
    Type: Grant
    Filed: May 6, 1999
    Date of Patent: September 3, 2002
    Assignee: Nortel Networks Limited
    Inventors: Chandra S. Bontu, Yonghai Gu, Shavantha Kularatna, Peter Barany
  • Publication number: 20020065081
    Abstract: A wireless network includes wireless access systems for communicating with mobile stations. At least one of the wireless access systems is capable of communicating with multiple types of mobile stations. One type of mobile station communicates according to the Enhanced General Packet Radio Service (EGPRS) protocol, while another type of mobile station communicates according to the GSM/EDGE Radio Access Network (GERAN) protocol. The wireless access system includes control logic to select one of plural types of protocol stacks to use for communications over an air link with the different types of mobile stations. In response to an indicator of a first type, the wireless access system selects a first protocol stack, and in response to an indicator of a second type, the wireless access system selects a second protocol stack.
    Type: Application
    Filed: August 30, 2001
    Publication date: May 30, 2002
    Inventors: Peter A. Barany, Chandra S. Bontu, Shamim Akbar Rahman
  • Publication number: 20020064164
    Abstract: A communications network includes a wireless core network that is coupled to a packet data network and/or a public circuit-switched network. The wireless core network includes wireless access systems that communicate over wireless links with mobile stations. The mobile stations are capable of participating in packet-switched communications session with another endpoint, such as one connected to the packet data network or the public circuit-switched network. To take advantage of existing channel coding and interleaving schemes, and to enhance spectral efficiency, protocol headers associated with packet-switched communications are not communicated with the bearer traffic (which can be voice or other forms of real-time traffic). The protocol headers are reconstructed at the receiving end, which may be the wireless access system or a mobile station. To enable the reconstruction of the protocol headers, configuration messages are exchanged between the mobile stations and the wireless access systems.
    Type: Application
    Filed: August 6, 2001
    Publication date: May 30, 2002
    Inventors: Peter A. Barany, Chandra S. Bontu
  • Publication number: 20020034166
    Abstract: A communications system includes a wireless access network that is coupled to a packet-based data network. Packet-based calls may be established between a mobile station coupled to the wireless access network and a network endpoint coupled to the data network. For efficient call setup and call release, call control signaling, such as Session Initiation Protocol (SIP) messages and Resource Reservation Protocol (RSVP) messages, are carried in traffic channels over the wireless access network.
    Type: Application
    Filed: December 15, 2000
    Publication date: March 21, 2002
    Inventors: Peter A. Barany, Chandra S. Bontu, Shamim Akbar Rahman