Patents Assigned to AT&T Wireless Svcs. Inc.
  • Patent number: 6229885
    Abstract: A method facilitates providing private exchange functionality to a subscriber that is remote from the private network. In the private network, telephones connected thereto can be accessed via extension dialing. The remote subscriber can dial the extension of a second telephone connected to said private network. A local exchange receives the extension and translates it into a phone number for the second telephone. The local exchange then uses the phone number to establish a connection between the subscriber and the second telephone. The same method can be used to implement remote speed dialing and automatic callback through the private network.
    Type: Grant
    Filed: October 10, 1997
    Date of Patent: May 8, 2001
    Assignee: AT&T Wireless Svcs. Inc.
    Inventors: Michael Buhrmann, Nicolas Kauser
  • Patent number: 6188736
    Abstract: An improved multi-antenna receiver is realized for detecting signals transmitted by a multi-antenna transmitter by summing signals received at the plurality of receiver antennas after multiplying each by a respective constant. The summed signal is applied to a maximum likelihood detector. The respective constants, &lgr;j, where j is an index designating a particular receiver antenna, are determined by evaluating the largest eigenvector of the matrix A, where &Lgr; is a vector containing the values &lgr;j, and A is a matrix containing elements &agr;ij, which is the transfer function between the ith transmitter antenna to the jth receiver antenna. The &agr;ij terms are determined in the receiver in conventional ways.
    Type: Grant
    Filed: April 21, 1998
    Date of Patent: February 13, 2001
    Assignee: AT&T Wireless Svcs. Inc.
    Inventors: Titus Lo, Vahid Tarokh
  • Patent number: 6188899
    Abstract: A method and system automatically activates a mobile station in a wireless communications network. The system includes an over the air activation function (OTAF) processor in the network that initiates an activation process in response to receiving a registration message from a mobile switching center serving the mobile station requesting the activation. Each mobile station has a unit of information stored into it at the time of its manufacture to enable it to request over the air activation. That unit of information is either the network routing address of the OTAF processor, or alternately, it is a value that is translatable into that address, either an OTAF ID number that is the same value for every mobile station or it is a sequentially serialized dummy value for the mobile identification number (a dummy MIN). When the mobile station is turned on for the first time in the network, it requests activation over the air by transmitting to the local mobile switching center a registration order.
    Type: Grant
    Filed: July 15, 1996
    Date of Patent: February 13, 2001
    Assignee: AT&T Wireless Svcs, Inc.
    Inventors: Arun K. Chatterjee, Brian Kevin Daly, David William James Holmes, Ileana A. Leuca
  • Patent number: 6188897
    Abstract: A method and apparatus for controlling roaming in a multiple service provider environment. When a mobile station determines that it can no longer obtain acceptable service from a primary service provider, the mobile station determines whether it is operating at the periphery of the primary service provider coverage area. If it is, then the mobile station is permitted to obtain service from a secondary service provider (i.e. roam). If it is determined that the mobile station is not operating at the periphery of the primary service provider coverage area, then the mobile station is prevented from roaming for a time period which allows the mobile station to emerge from a presumed coverage hole.
    Type: Grant
    Filed: August 17, 1998
    Date of Patent: February 13, 2001
    Assignee: AT&T Wireless Svcs. Inc.
    Inventor: Roderick Nelson
  • Patent number: 6175555
    Abstract: In a time division duplex (TDD) system, compensation measurements are made for the transmission circuitry during the receive portion of the TDD cycle and compensation measurements are made for the receive circuitry during the transmit portion of the TDD cycle. A base station has multiple antennas for spatial, as well as spectral, spreading and despreading of discrete multitone spread spectrum (DMT-SS) communications. Each antenna has its own transmission path components and receive path components. The transmit amplifier, for example, in the transmit path and the receive amplifier, for example, in the receive path tend to drift in their characteristics over time. The invention manages the sequential testing of each respective transmission path and receive path for each antenna. The invention measures the drift of the transmit path components and the receive path components and prepares compensating weights to be applied to signals processed in each path.
    Type: Grant
    Filed: June 11, 1998
    Date of Patent: January 16, 2001
    Assignee: AT&T Wireless Svcs. Inc.
    Inventor: Elliott D. Hoole
  • Patent number: 6169895
    Abstract: A data collection method, system and private base station collects data from at least one data generator positioned within a premises and forwards the data to a private base station along a communication channel. Communication is first attempted with a landline telephone network. If this is unsuccessful, a call containing the data is forwarded through a wireless cellular phone network to a desired destination such as a monitoring service.
    Type: Grant
    Filed: December 17, 1996
    Date of Patent: January 2, 2001
    Assignee: AT&T Wireless Svcs. Inc.
    Inventors: Michael Buhrmann, Ileana A. Leuca
  • Patent number: 6167261
    Abstract: Network resources associated with a wireless communication network are assigned to a wireless communication device in accordance with its device type and required service type. A profile is associated with each wireless communication device, and includes a travelling class mark field which identifies the device type of the wireless communication device, and a service class mark field which identifies the required service for the wireless communication device. Different wireless communication devices are accommodated via different profiles. The profiles are permanently stored at a service control point which is accessible to a plurality of mobile service centers.
    Type: Grant
    Filed: February 27, 1997
    Date of Patent: December 26, 2000
    Assignee: AT&T Wireless Svcs. Inc.
    Inventor: Umesh J. Amin
  • Patent number: 6167274
    Abstract: A method provides for the detection of the geographic location of a mobile station within a mobile network. The mobile station detects signal characteristics for signals generated by neighboring cells to create a report of signal characteristics corresponding to the location at which the mobile station resides. This report is then compared against the database of signal signatures identifying geographic locations within the cell in which the mobile station is known to be positioned. The signal signatures are then used to detect either an exact match or an approximate match to give position information of the mobile station within the cell.
    Type: Grant
    Filed: June 3, 1997
    Date of Patent: December 26, 2000
    Assignee: AT&T Wireless Svcs. Inc.
    Inventor: Adrian David Smith
  • Patent number: 6160839
    Abstract: A new method makes the most efficient use of the scarce spectral bandwidth in a wireless discrete multitone spread spectrum communications system by updating the spectral and/or spatial spreading weights at a rate that is determined by the measured quality of the link. Low quality links require more frequent updates of the spreading weights than do higher quality links. Spreading weights and despreading weights for a station are adaptively updated, depending on the error in received signals. If the error value is less than a threshold error value, then the method maintains the existing spreading weights as the current spreading weights to apply to an outgoing data signal. Alternately, if the error value is greater than the threshold error value, then the method adaptively calculates updated despreading weights at the base station from the first spread signal and calculates updated spreading weights as the current spreading weights from the updated despreading weights to apply to the outgoing data signal.
    Type: Grant
    Filed: April 26, 1999
    Date of Patent: December 12, 2000
    Assignee: AT&T Wireless Svcs. Inc.
    Inventor: Hongliang Zhang
  • Patent number: 6158008
    Abstract: A dedicated data packet filtering processor whose only function is to filter data packets based on a list of source IP addresses stored in high-speed memory of the processor. The processor has a specialized operating system which controls the operation of the processor. The processor examines the source IP address of each received data packet to determine if the source IP address matches one of the stored source IP addresses, and if there is a match, either discards or forwards the data packet depending on the processor configuration. The list of source IP addresses are updated by a service provider having a central administrative site. The service provider keeps these lists up to data and periodically updates the source IP addresses stored in the random access memory of the dedicated IP filtering processors.
    Type: Grant
    Filed: October 23, 1997
    Date of Patent: December 5, 2000
    Assignee: AT&T Wireless Svcs. Inc.
    Inventors: Arturo Maria, Leslie Dale Owens
  • Patent number: 6141545
    Abstract: A subscriber to a remote call forwarding feature on a wire-line telephone line associated with a PBX (101) or central office (402) can enable that feature by dialing feature code from his cellular phone (103, 403). The subscriber dials a feature code from his cellular phone, which feature code is received by the cellular phone's Mobile Switching Center (MSC) (105, 405) and forwarded to a Service Control Point (SCP) (106, 406). The SCP recognizes the feature code as a request to invoke the remote call forwarding feature on the subscriber's wire-line telephone so that calls directed to that wire-line telephone are forwarded to the cellular phone. Receipt of that feature code by the SCP, together with the cellular phone's Electronic Serial Number (ESN) and Mobile Identification Number (MIN) identifies the subscriber and the feature to be invoked for that subscriber.
    Type: Grant
    Filed: January 22, 1998
    Date of Patent: October 31, 2000
    Assignee: AT&T Wireless Svcs Inc.
    Inventors: Lee Begeja, Jeffrey Joseph Farah, Neil A. Ostroff
  • Patent number: 6134261
    Abstract: A highly bandwidth-efficient communications method is disclosed, to maximize the signal-to-interference-noise ratio (SINR) of transmissions from a base station to a remote station in a wireless communications system. The method is used for base stations that have a plurality of antenna elements that are capable of spatial beam steering by altering the relative phase of transmission of signals from the respective elements. The method of the invention is based on providing calibration frames that sequentially transmit calibration bursts from the respective antenna elements for a particular destination remote station. The calibration bursts include a plurality of tone frequencies arranged in a distinctive orthogonal frequency division multiplexed pattern unique to the base station. The unique pattern enables a remote station to distinguish the base station's bursts from other signals present in a crowded area.
    Type: Grant
    Filed: March 5, 1998
    Date of Patent: October 17, 2000
    Assignee: AT&T Wireless Svcs. Inc
    Inventor: David James Ryan
  • Patent number: 6125122
    Abstract: Two intelligent nodes are provided with the capability of negotiating a protocol between them so that if the intelligent nodes operate at two different protocols then they can select a protocol appropriate for their communication. Furthermore, the intelligent nodes are provided with a locking shift capability so as to select between codesets that are available within a selected protocol.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: September 26, 2000
    Assignee: AT&T Wireless Svcs. Inc.
    Inventors: Frank Favichia, Eamon O'Leary
  • Patent number: 6092110
    Abstract: A dedicated data packet filtering processor whose only function is to filter data packets based on a list of source IP addresses stored in high-speed memory of the processor. The processor has a specialized operating system which controls the operation of the processor. The processor examines the source IP address of each received data packet to determine if the source IP address matches one of the stored source IP addresses, and if there is a match, either discards or forwards the data packet depending on the processor configuration. The list of source IP addresses are updated by a service provider having a central administrative site. The service provider keeps these lists up to data and periodically updates the source IP addresses stored in the random access memory of the dedicated IP filtering processors.
    Type: Grant
    Filed: October 23, 1997
    Date of Patent: July 18, 2000
    Assignee: AT&T Wireless Svcs. Inc.
    Inventors: Arturo Maria, Leslie Dale Owens