Patents by Inventor Ashvin Chheda

Ashvin Chheda 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).

  • Publication number: 20030231586
    Abstract: Provided is a system and method for maximizing the number of communication sessions in a telecommunications network. The network includes multiple protocols that each utilize a certain number of codes and a certain amount of power. Accordingly, the desirability of each protocol may vary depending on the number of codes and the amount of power available. A code usage level and a power usage level for the network are obtained and compared to determine whether the network is using a higher percentage of the available codes or a higher percentage of the available power. If a higher percentage of codes are in use, a new session may be established using a protocol that uses relatively few codes but more power. Likewise, if a higher percentage of power is in use, the new session may be established using a protocol that uses relatively little power but more codes.
    Type: Application
    Filed: December 10, 2001
    Publication date: December 18, 2003
    Applicant: Nortel Networks Limited
    Inventor: Ashvin Chheda
  • Patent number: 6590874
    Abstract: A signalling method for controlling unnecessary power increases and call drop during discontinuous transmission (DTX) mode of a frame-based transmission system. The signalling method comprises the steps of (1) detecting, at a receiver end of the transmission system a status of a transmitted frame indicating one of two possible transmission modes including (a) when a gating-off of the traffic channel occurs, and (b) when no gating-off of traffic occurs and normal traffic is being transmitted, and (2) controlling a change in the receiver target bit energy to noise spectrum density ratio Eb/No in response to the detection step so that a receiver target Eb/No is increased only when the detecting step does not indicate a gating-off of traffic has occurred.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: July 8, 2003
    Assignee: Nortel Networks Limited
    Inventors: Yiping Wang, David Paranchych, Ashvin Chheda
  • Patent number: 6587447
    Abstract: A method for controlling unnecessary power increases and call drop during discontinuous transmission (DTX) mode of a frame-based transmission system. The method comprises the steps of (1) detecting, at a receiver end of the transmission system a status of a transmitted frame indicating one of two possible transmission modes including (a) when a gating-off of the traffic channel occurs, and (b) when no gating-off of traffic occurs and normal traffic is being transmitted, and (2) controlling a change in the receiver target bit energy to noise spectrum density ratio Eb/No in response to the detection step so that a receiver target Eb/No is increased only when the detecting step does not indicate a gating-off of traffic has occurred.
    Type: Grant
    Filed: September 29, 1999
    Date of Patent: July 1, 2003
    Assignee: Nortel Networks Limited
    Inventors: Yiping Wang, David Paranchych, Ashvin Chheda
  • Patent number: 6515975
    Abstract: Disclosed is an apparatus for and method of increasing the stability of a CDMA cellular system using fast forward power control. This is accomplished by improving the relative power level synchronization of all the BTSs communicating with an MS in a handoff mode through the use of at least one of 1) setting the power levels of any BTS other than the BTS having the best measured Eb/No (bit energy to noise density) of reverse link FPC (forward power control) bit stream transmissions from said MS, hereinafter BTS(x), to a power level which is a function of the power level of BTS(x), 2) adjusting at least one of lower and upper limits of traffic channel gain of a BTS as a function of whether or not said given MS is in a handoff mode and 3) adjusting at least one of the incremental FPC (forward power control) and RPC (reverse power control) parameters as a function of the number of BTSs in a soft handoff mode with respect to said MS.
    Type: Grant
    Filed: April 22, 1999
    Date of Patent: February 4, 2003
    Assignee: Nortel Networks Limited
    Inventors: Ashvin Chheda, Ahmad Jalali
  • Patent number: 6266529
    Abstract: A method for improved sector handoff within a sectorized communication cell utilizing a wireless communication systems. A sector handoff of a mobile radio telephone is performed in accordance with a first set of parameters if the mobile radio telephone is not in close proximity to a base antenna. Sector handoff of the mobile radio telephone is performed in accordance with a second different set of parameters when the mobile radio telephone is in close proximity of the base antenna. The second different set of parameters are utilized in close proximity to the base antenna to avoid drops and adverse handoffs in high interference, low signal strength areas and provide improved sector handoff when the mobile radio telephone encounters distorted conditions, such that improved sector handoff can be achieved.
    Type: Grant
    Filed: May 13, 1998
    Date of Patent: July 24, 2001
    Assignee: Nortel Networks Limited
    Inventor: Ashvin Chheda
  • Patent number: 6233455
    Abstract: A pre-determined negative constant is utilized in soft handoff mode to permit a new pilot signal to be added to an wireless phone's active set. The negative constant is combined with the weakest pilot signal in the active set and then compared to the new pilot signal strength which allows the new pilot to trigger a Pilot Strength Measurement Message (PSMM) even when the new pilot signal is weaker than all active set pilot signals. The negative constant provides a soft handoff while maintaining or reducing drop rate probabilities and frame error rates. After initially triggering a PSMM, the next instance the new pilot may ordinarily cause a PSMM to be triggered is when the new pilot signal exceeds the strongest active set pilot signal. Triggering a PSMM when exceeding the strongest active set signal may increase the probability of dropped signals. To reduce the probability of dropped signals, a negative constant is utilized during soft handoff to add a new pilot to an active set.
    Type: Grant
    Filed: May 3, 1999
    Date of Patent: May 15, 2001
    Assignee: Nortel Networks Limited
    Inventors: Deepa Ramakrishna, Ahmad Jalali, Ashvin Chheda
  • Patent number: 6188914
    Abstract: A system and method for improving link performance and network capacity of a CDMA network is described. In a preferred embodiment, at each sector site, antennas having a relatively narrow horizontal beamwidth are used as transmit antennas, while antennas having a relatively wide horizontal beamwidth are used as receive antennas. Narrow beamwidth antennas are also used to implement hybrid transmit/receive antennas.
    Type: Grant
    Filed: October 22, 1997
    Date of Patent: February 13, 2001
    Assignee: Nortel Networks Limited
    Inventor: Ashvin Chheda
  • Patent number: 6181738
    Abstract: When the frame rate changes from eighth rate to full rate, the power control process increases the Eb/No target by &Dgr;1. If the frame rate changes from full rate to eighth rate, the power control process decreases the Eb/No target by &Dgr;2. In both cases, a decision threshold for a Frame Quality Metric is determined. If the Frame Quality Metric is less than the threshold, normal power control is resumed. If the Frame Quality Metric is greater than or equal to the threshold, the newly set target Eb/No is decreased by A3. The target Eb/No is continually decreased by A until the frame rate changes or the target reaches the required Eb/No, indicated by a bad frame or lower frame quality metric (i.e., lower than the frame quality threshold).
    Type: Grant
    Filed: February 13, 1998
    Date of Patent: January 30, 2001
    Assignee: Northern Telecom Limited
    Inventors: Ashvin Chheda, Ahmad Jalali
  • Patent number: 6151512
    Abstract: A configuration of base stations and sectors within cells of a CDMA wireless communication network provide greater call handling capacity. By optimally configuring sectors of a cell controlled by multiple base stations, fewer channel elements are required to implement the desired service and a resultant system has improved signal demodulation, lower power requirements, improved performance, and lower cost for a service provider. The base stations are configured to support "N" sectored cells to ensure that each cell has a maximum amount of capacity for all mobile users therein. This method involves configuring the sectors serviced by a same base station adjacent to one another. By configuring the sectors associated with base stations in this manner, there are fewer instances of soft handoff and more instances of softer handoff. Furthermore, configuring the sectors to be adjacent to one another ensures optimal power collection by each of the sectors during the communication process.
    Type: Grant
    Filed: May 28, 1997
    Date of Patent: November 21, 2000
    Assignee: Nortel Networks Corporation
    Inventors: Ashvin Chheda, Farhad Bassirat
  • Patent number: 6075815
    Abstract: The process determines the I channel and Q channel components for each received soft value. The location of each soft value with respect to the fade line is determined using the I and Q channel components. These locations are averaged over a power control group duration to determine the noise density. The symbol energy is determined by subtracting the average perpendicular distance from the soft value point to the fade line from half the square of the average of the distance from the soft value point to the origin.
    Type: Grant
    Filed: September 17, 1997
    Date of Patent: June 13, 2000
    Assignee: Nortel Networks Corporation
    Inventors: Ashvin Chheda, Michael S. Feeney, Ahmad Jalali
  • Patent number: 6073025
    Abstract: The base station controller monitors the reverse link frame error rate of all the base stations involved in a soft hand-off with a radiotelephone. The average reverse link frame error rates of these base stations are then computed and the lowest of the average error rates is found. The last known transmit power of the base station having the lowest average error rate is determined. The transmit power of those base stations having a higher average reverse link frame error rate than the best base station are adjusted to the last known transmit power of the best base station.
    Type: Grant
    Filed: September 17, 1997
    Date of Patent: June 6, 2000
    Assignee: Nortel Networks Corporation
    Inventors: Ashvin Chheda, Michael S. Feeney, Ahmad Jalali
  • Patent number: 5963870
    Abstract: The power control process switches between IS-95 forward power control and fast forward power control using either speed or hand-off status information from the mobile radiotelephone. If the received information indicates either a slower speed or the number of communication links is less than a predetermined number, the fast forward power control process is used. If the received information indicates either a fast speed or the number of links is greater than or equal to the predetermined number (the radiotelephone is in a hand-off situation), the forward power control process is used.
    Type: Grant
    Filed: September 17, 1997
    Date of Patent: October 5, 1999
    Assignee: Nortel Networks Corporation
    Inventors: Ashvin Chheda, Michael S. Feeney, Ahmad Jalali
  • Patent number: 5960349
    Abstract: An enhanced cellular layout for cellular networks having six-sectored cells is disclosed. In one embodiment, the cellular layout is implemented by rotating directional antennas located at each cell site of a triangular cellular layout of a six-sectored CDMA network clockwise or counterclockwise by approximately 10.893.degree. or rotating directional antennas located at each cell site of a parallelogram cellular layout of a six-sectored CDMA network clockwise or counterclockwise by approximately 19.107.degree..
    Type: Grant
    Filed: May 20, 1997
    Date of Patent: September 28, 1999
    Assignee: Northern Telecom
    Inventors: Ashvin Chheda, Farhad Bassirat
  • Patent number: 5946621
    Abstract: System and method for optimally updating a neighbor set for use by a mobile unit during soft handoff of the mobile unit in a CDMA cellular telephone environment is disclosed. A two-step process is used to ensure that the individual neighbor sets of active set members are combined in a manner such that only pilots representing the more important sectors are included in the updated neighbor set and pilots representing the less important sectors are excluded therefrom. In the first step, active set members whose RTD is more than twice as great as an OWD threshold are eliminated from consideration. In the second step, the neighbor set of the mobile unit is updated using the sectors included in the individual neighbor sets of the active set members that were not excluded by the first step, wherein those sectors are included in the updated neighbor set according to the number of individual sets in which they are found and their priority within those sets.
    Type: Grant
    Filed: October 28, 1996
    Date of Patent: August 31, 1999
    Assignee: Northern Telecom Limited
    Inventors: Ashvin Chheda, Ahmad Jalali