Patents by Inventor Krishna Balachandran

Krishna Balachandran 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: 7385951
    Abstract: In a wireless communication system, there is a method of transmitting over a reverse link, where a medium access control layer multiplexes data from upper level layers onto transport channels that are used based on whether the user is in a scheduled transmission mode or an autonomous transmission mode. The transport channels may be mapped to one or more physical channels associated with a particular transport channel, based on whether the transport channel is dedicated for use in the scheduled or autonomous mode.
    Type: Grant
    Filed: February 15, 2003
    Date of Patent: June 10, 2008
    Assignee: Lucent Technologies Inc.
    Inventors: Krishna Balachandran, Arnab Das, Ashwin Sampath
  • Patent number: 7372823
    Abstract: Rather than transmitting a large full Broadcast-Multicast Services (BCMC) Parameters Message (BSPM) containing a full set of BSPM parameters pertaining to all active BCMC flows within a sector on an infrequent basis, smaller-sized differential or partial BSPMs are instead transmitted. Differential BSPMs contain updated information for existing flows or information for new flows, and because of their smaller size, can be transmitted more frequently than full BSPMs. A mobile terminal receiving a differential BSPM updates the flows with the information contained within the differential BSPM or adds the information contained within the differential BSPM for a new flow. Partial BSPMs divide the flow information contained in a large full BSPM over a plurality of smaller-sized partial BSPMs, which are separately and sequentially transmitted at different times. A mobile terminal receiving these partial BSPMs then reconstructs the full BSPM from a collection of received partial BSPMs.
    Type: Grant
    Filed: March 22, 2004
    Date of Patent: May 13, 2008
    Assignee: Lucent Technologies Inc.
    Inventors: Krishna Balachandran, Kenneth C Budka, Arnab Das, Joseph H Kang
  • Patent number: 7356561
    Abstract: In a multiple node network, the method includes waking up at least one node from a sleep mode during at least one associated slot of a time-slotted frame, the sleep mode being a low power consumption mode. Also, in at least one node of a multiple node network, the period of time a node sleeps is based on the residual energy of the node, the residual energy of the nodes in the neighborhood, neighborhood node density, and combinations thereof.
    Type: Grant
    Filed: May 1, 2003
    Date of Patent: April 8, 2008
    Assignee: Lucent Technologies Inc.
    Inventors: Krishna Balachandran, Joseph H. Kang, Wing Cheong Lau
  • Patent number: 7352714
    Abstract: Methods and apparatuses for allocating control and data time slots to a plurality of wireless mobile stations in a wireless communication system using time division multiplexing. The methods and apparatuses assign such time slots by first placing the wireless mobile stations into a number of different groups. Then, control time slots and anchor data time slots are assigned to the groups in the uplink and downlink frames of a carrier such that the uplink control time slot for each group is maximally spaced in time relative to the downlink control time slot for the same group. Data time slots are subsequently assigned to a particular mobile station by assigning time slots in the uplink and downlink frames which are as close as possible to the group's uplink or downlink anchor data time slots, as the case may be, according to a “grow from center” technique.
    Type: Grant
    Filed: September 24, 2002
    Date of Patent: April 1, 2008
    Assignee: Lucent Technologies Inc.
    Inventors: Krishna Balachandran, Kirk K. Chang, Wei Luo, Sanjiv Nanda
  • Publication number: 20080075145
    Abstract: In an ad hoc wireless network, for purposes of neighbor discovery, a transmitting node transmits a beacon within a timeslot and at a frequency that varies from timeslot-to-timeslot according to one or more associated and known pseudo-random or cyclical frequency hopping sequences. When, during a timeslot, the frequency hopping sequence would select a beacon frequency that if transmitted would violate spectrum policy that is in place during that timeslot, then, during that timeslot, a beacon is not transmitted during that timeslot. During each timeslot, a neighbor receiving node attempts to detect and decode a transmitted beacon at a frequency specified by the frequency hopping sequence that it expects a transmitting node to be using. When a receiving node successfully detects and decodes a beacon transmitted by a transmitting node, neighbor discovery between the transmitting and receiving nodes is achieved.
    Type: Application
    Filed: September 22, 2006
    Publication date: March 27, 2008
    Inventors: Krishna Balachandran, Joseph H. Kang
  • Publication number: 20080075032
    Abstract: The present invention provides a method for allocating portions of a frame to a plurality of mobile units including a plurality of frequency subcarrier sets and a plurality of symbols. The method includes determining at least one zone comprising at least one of the plurality of subcarrier sets and at least one of the plurality of symbols and determining a plurality of subzones. Each subzone includes at least one of the plurality of subcarrier sets and at least one of the plurality of symbols in the at least one zone. The method also includes associating each of the plurality of mobile units with at least one of the subzones and allocating a portion of the subcarrier sets and symbols in each subzone to the mobile units associated with each subzone.
    Type: Application
    Filed: September 22, 2006
    Publication date: March 27, 2008
    Inventors: Krishna Balachandran, Doru Calin, Niranjan Sudhir Joshi, Joseph H. Kang, Achilles Kogiantis
  • Patent number: 7349338
    Abstract: A scheduler and a method for scheduling transmissions to a plurality of users in a communication network assigns a higher target minimum throughput for receiving a next transmission to a user based on a quality of service (QoS) class of the user. A token count that tracks the user's achieved performance relative to a target minimum throughput Is determined for each user in given timeslot, and a weight is determined for each user based on one or more of the token count and a current rate requested by the user. A user having the highest weight as determined by a weight function is scheduled to be served the next transmission. User priority for scheduling may be downgraded if an average data rate requested by the user is less than the target minimum throughput.
    Type: Grant
    Filed: April 15, 2003
    Date of Patent: March 25, 2008
    Assignee: Lucent Technologies Inc
    Inventors: Krishna Balachandran, Kenneth C. Budka, Arnab Das, Kameswara Rao Medapalli, Minothi Parulekar
  • Patent number: 7304971
    Abstract: In the method, information from a user is transmitted over one or more communication channels of a wireless communication system by code multiplexing transmissions in the code domain. The method may include code multiplexing a first information from the user over a first channel with a second information from the user over a second channel, and determining a transmission format for the first and second channels. The transmission format may be determined based on one or more of available transmit power, transmission time interval, a coding dimension used for multiplexing, and transmit power used per code. The first information and second information are transmitted over the respective channels based on the determined transmission format.
    Type: Grant
    Filed: November 1, 2002
    Date of Patent: December 4, 2007
    Assignee: Lucent Technologies Inc.
    Inventors: Krishna Balachandran, Arnab Das, Ashwin Sampath, Hsuan-Jung Su
  • Publication number: 20070237092
    Abstract: In an ad hoc network in which nodes communicate directly with each other or through another node, hole exchange messages are transmitted on an ongoing basis from one node to one or more other nodes. The spectrum hole message transmitted by a node provides a current view of the frequency spectrum as seen by the transmitting node, indicating where in the spectrum holes exist that are available for transmission. Hole exchange messages are transmitted by a node in response to either time triggers or event triggers. The former includes transmitting a hole exchange message periodically, pseudo-periodically, or according to a timer expiry. The latter includes events such as the node discovering the presence of a new node, receiving a request from another node for the node's current view of the spectrum, upon bearer selection during call setup between the node and another node, degradation of the link between the node and another node, and upon bearer release between the node and another node.
    Type: Application
    Filed: September 19, 2005
    Publication date: October 11, 2007
    Inventors: Krishna Balachandran, Joseph Kang
  • Patent number: 7260396
    Abstract: In a method of tracking a user in a communication network supporting a broadcast-multicast service, the network classifies groups of users into tracking areas. Movement of a user may be tracked as the user crosses a boundary between two tracking areas in the network. The method may enable a balance to be achieved between use of uplink overhead and the level or granularity of tracking desired, so as to conserve radio resources.
    Type: Grant
    Filed: August 19, 2003
    Date of Patent: August 21, 2007
    Assignee: Lucent Technologies Inc.
    Inventors: Krishna Balachandran, Kenneth C. Budka, Arnab Das, Michael F. Dolan, Joseph H. Kang
  • Publication number: 20070178917
    Abstract: In a method of receiving signaling information in a communication network supporting a broadcast-multicast service, a first channel containing at least one indicator related to signaling information for a broadcast-multicast service is decoded to determine whether to monitor a second channel for the signaling information.
    Type: Application
    Filed: March 16, 2007
    Publication date: August 2, 2007
    Inventors: Krishna Balachandran, Kenneth Budka, Arnab Das, Joseph Kang
  • Publication number: 20070149217
    Abstract: In a method of tracking a user in a communication network supporting a broadcast-multicast service, the network classifies groups of users into tracking areas. Movement of a user may be tracked as the user crosses a boundary between two tracking areas in the network. The method may enable a balance to be achieved between use of uplink overhead and the level or granularity of tracking desired, so as to conserve radio resources.
    Type: Application
    Filed: March 1, 2007
    Publication date: June 28, 2007
    Inventors: Krishna Balachandran, Kenneth Budka, Arnab Das, Michael Dolan, Joseph Kang
  • Patent number: 7236789
    Abstract: In the method for selecting a channel rate, link quality between the serving portion of the network and a mobile station is determined from at least one signal strength measurement. A channel rate is then selected based on the determined link quality. Also, a physical channel is assigned to the mobile station on a prioritized basis with respect to the selected channel rate.
    Type: Grant
    Filed: February 27, 2003
    Date of Patent: June 26, 2007
    Assignee: Lucent Technologies Inc.
    Inventors: Krishna Balachandran, Tingfang Ji, Joseph H. Kang, James P. Seymour
  • Patent number: 7187715
    Abstract: An adaptive pulse position modulated CDMA scheme for use in UWB communications systems is disclosed. A stream of input bits is encoded with spreading code sequence. The spreading code sequence consists of a number of code elements that may have one of two values. Each bit is encoded into a symbol consisting of a predefined number of chips, which are transmitted during a symbol period. Next, at least one code element is associated with each chip in the symbol. Then, an encoded pulse is generated in each chip. Each encoded pulse has a value determined by multiplying the data bit with the code value associated with the particular chip. The encoded pulse is then pulse position modulated by shifting the position of the pulse to a first position or a second position within the chip depending upon the encoded value of the pulse.
    Type: Grant
    Filed: September 23, 2002
    Date of Patent: March 6, 2007
    Assignee: Lucent Technologies Inc.
    Inventors: Krishna Balachandran, Doru Calin, Tingfang Ji, Joseph H. Kang
  • Publication number: 20070049314
    Abstract: A push-to-talk (“PTT”) group call system, for use as, e.g., a public safety wireless network, includes a CDMA-based 1x-EVDO radio access network operably connected to a PTT server over an IP network. The radio access network includes base stations for radio communications with a number of distributed mobile stations. In carrying out wireless communications, the group call system combines IP-based voice and other real-time multimedia services with the 1x-EVDO radio access network's Broadcast Multicast Service. This allows a number of users to receive the same copy of an IP-based media stream for point-to-multipoint, group transmissions. To reduce call setup times, the group call system uses “standing” call groups, which are ongoing group communication channels pre-established between the PTT server and authorized group users. Thus, mobile stations link to one or more standing call groups of interest upon power-up, prior to users speaking.
    Type: Application
    Filed: August 30, 2005
    Publication date: March 1, 2007
    Applicant: Lucent Technologies Inc.
    Inventors: Krishna Balachandran, Kenneth Budka, Joseph Kang
  • Publication number: 20070047478
    Abstract: A method for access assurance in a wireless communication system, e.g., a mobile phone network, involves allocating communication resources for transactions between the network and various wireless access terminals (each having a unique identifier) based on priority classes assigned to the access terminals. The access terminals are divided into different priority classes based on public policy and similar considerations. Each access terminal's priority class is associated with its identifier in a database. Upon communicating with an access terminal, the network determines the access terminal's priority class based upon its identifier as received by the network, e.g., the identifier is correlated to the priority class in the database. Transaction priority levels are then calculated based on each access terminal's priority class. Air interface resources are allocated according to the computed transaction priority levels and one or more pre-determined allocation precedence rules governing priority.
    Type: Application
    Filed: August 30, 2005
    Publication date: March 1, 2007
    Applicant: Lucent Technologies Inc.
    Inventors: Krishna Balachandran, Kenneth Budka, Joseph Kang
  • Publication number: 20060245470
    Abstract: In a wireless communications system which hops from frequency to frequency, rather than hopping according to a fixed dwell interval and a pre-determined pseudo-random hop sequence, a quality-based frequency hopping methodology is defined in which a new frequency is hopped to when the channel quality on the current frequency degrades based on the measured value or values of one or more predetermined metrics that are associated with channel quality. When triggered to hop to a next frequency, the hop-to-frequency may be the next frequency in the pseudo-random hop sequence known to both the transmitter and receiver or, in order to improve the reliability of communications, may be determined based on channel quality measurements on different potential hop-to-frequencies.
    Type: Application
    Filed: April 29, 2005
    Publication date: November 2, 2006
    Inventors: Krishna Balachandran, Joseph Kang
  • Patent number: 7116982
    Abstract: Systems and methods for intelligently assigning a channel to a device being used by a mobile user in a power controlled, wireless communications system by minimizing the difference between a mobile user's received signal power and the minimum received signal power of a current user on a candidate carrier frequency. Each carrier frequency within a cell is examined to determine whether it has at least one current user assigned to a channel and also has at least one unoccupied channel. For each carrier frequency that meets both of these requirements, a channel quality metric is obtained for each occupied channel. The carrier frequencies are pruned down to a subset of candidate carrier frequencies using the channel quality metrics. Finally, a channel within the set of candidate carrier frequencies is selected by computing a cost function based on the received signal power of the mobile user and the received signal power of each occupied channel.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: October 3, 2006
    Assignee: Lucent Technologies Inc.
    Inventors: Krishna Balachandran, Joseph H. Kang
  • Patent number: 7082153
    Abstract: Methods and systems for generating a variable spacing pulse position modulated (VSPPM) signal for transmission across an ultra-wideband communications channel. The variable pulse position modulated spread spectrum signal is created by encoding every M input data bits from an input data stream into a symbol consisting of Nc chips. Each chip is divided into 2M sub-chips and each sub-chip is further divided into Np time slots. A pulse is transmitted for each chip in the symbol. During each chip period, the pulse is placed in the sub-chip corresponding to the binary M-tuple (or symbol) value. A time hopping code sequence consisting of Nc elements with a one-to-one chip association is then applied to each symbol so that the position of each pulse is shifted to the appropriate time slot that corresponds to the time hopping code value.
    Type: Grant
    Filed: September 23, 2002
    Date of Patent: July 25, 2006
    Assignee: Lucent Technologies Inc.
    Inventors: Krishna Balachandran, Doru Calin, Tingfang Ji, Joseph H. Kang
  • Patent number: 7068619
    Abstract: In a mobile station-mobile receiver arrangement a method and apparatus for a radio link control (RLC) protocol that allows partial recovery of data for streaming services. The maximum number of retransmissions allowed by the method for each RLC block is a function of the maximum delivery delay required by the streaming service and the round trip delay.
    Type: Grant
    Filed: May 2, 2001
    Date of Patent: June 27, 2006
    Assignee: Lucent Technologies Inc.
    Inventors: Krishna Balachandran, Kirk K. Chang, Richard Paul Ejzak, Wei Luo, Sanjiv Nanda