Crystal Or Electron Tube Diode Patents (Class 455/331)
  • Patent number: 5442680
    Abstract: A cellular cordless telephone may receive cellular telephone calls via a cellular telephone system and receive telephone calls on a system having a limited radio coverage area. To reduce the amount of time spent in monitoring the sub-data channel of the limited coverage area system, a timing signal is generated which represents the period of time spent monitoring the radio channel. During the monitoring, a predetermined number of data words transmitted on the limited radio coverage area radio channel system are received. When a first received data word is detected, an allowed monitoring time value is adjusted to be the sum of the value of the timing signal and the product of a determined number of received words to be detected and the time required for each word. This adjusted value of the monitoring time value is compared to the value of the timing signal and when the adjusted monitoring time value equals or exceeds the timing signal value, the monitoring of the radio channel ceases.
    Type: Grant
    Filed: August 25, 1994
    Date of Patent: August 15, 1995
    Assignee: Motorola, Inc.
    Inventors: Michael J. Schellinger, Stefan G. Littig
  • Patent number: 5442682
    Abstract: A method for registering traffic data from mobile stations in a mobile telecommunication system. The mobile telecommunication system includes mobile switching centers and connected with these, base station controllers, so-called primary- and secondary base station controllers. Base stations are connected to the base station controllers, each base station covering a cell and each base station controller thereby covering a cell area containing several cells. Traffic data from a selected mobile is stored in the primary base station controller of the mobile. A trace invocation message is sent from the primary base station controller to the secondary base station controller, via the mobile switching center, when the mobile moves to a cell handled by the secondary base station controller. Registration of traffic data is thereafter effected in the secondary base station controller.
    Type: Grant
    Filed: December 20, 1994
    Date of Patent: August 15, 1995
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventors: Lars-Erik Svedin, Lars K. Linden, Lars M. Andersson, Cecilia S. M. Hedin, Ingrid V. Nordstrand, Stig R. Bodin
  • Patent number: 5442805
    Abstract: A method (200) and apparatus (100)is provided for a radio having adjustable operating parameters to adjust at least one such adjustable operating parameter based on the current location of the radio. Operating parameters which may be so adjusted include, but are not limited to, the following: transmitting power, operating channel, operating band, modulation type, modulation index, frequency deviation, squelch setting, channel spacing, control channel (for trunked communications), noise blanker characteristic, and receive bandwidth. In another embodiment, transmissions by the radio can be inhibited as a function of the location when it is determined that the location is within a hazard area.
    Type: Grant
    Filed: June 2, 1992
    Date of Patent: August 15, 1995
    Assignee: Motorola, Inc.
    Inventors: Richard C. Sagers, William D. Werner, Scott M. Hall, David W. Heinzelmann
  • Patent number: 5442806
    Abstract: A method and an apparatus for selecting a cellular carrier frequency for accessing cellular airtime services based upon a list of preferred system identification codes (SIDs). A cellular telephone is programmed to accept into memory a list of preferred SIDs corresponding to carriers through which service is preferred. While any SID remains in a preferred list, the standard A/B system selection function is replaced by a substitute system selection function which includes only three carrier selection modes including the Home Only mode, the SID Only mode, and a Roam Saver mode. With the Roam Saver carrier selection mode, the cellular telephone first prefers service through a home carrier and then through a carrier broadcasting a SID matching a SID on the preferred list, but never denies service to emergency or non-emergency destinations if any SID is detected.
    Type: Grant
    Filed: June 8, 1993
    Date of Patent: August 15, 1995
    Assignee: Oki Telecom
    Inventors: Clifton J. Barber, Stephen T. Hardin
  • Patent number: 5442804
    Abstract: The present invention relates to a method for resource allocation in a radio system comprising base stations with respective coverage areas and mobile units. The interaction between the stations in the system is defined with the aid of measured and/or calculated field strengths from all base stations on relevant traffic routes in the geographic area of the radio system, preferably in the form of an exclusion matrix. An allocating matrix is formed by compressing the exclusion matrix by means of an allocating algorithm. The algorithm utilizes figures of merit which are on the one hand calculated by mathematical/logical means to form possible combinations of stations and utilizes on the other hand a random technique for selecting one of these combinations. The algorithm is iterated a number of times and different allocations are obtained thanks to the random technique. The best one of the allocations from any point of view is selected.
    Type: Grant
    Filed: October 25, 1991
    Date of Patent: August 15, 1995
    Assignee: Televerket
    Inventors: Krister Gunmar, Ulf Tegth
  • Patent number: 5438565
    Abstract: A system for relaying CDMA packetized data from a cell site or sites to a destination speech processor. The CDMA packetized data, is received at the cell site and is sent in its packetized form along with a destination address to a packet switch. A packet handler at the packet switch receives the CDMA data packets and forwards them on a packet bus. If the destination speech processor assigned to that call is connected to the packet bus, it recognizes its own address and processes the data packet.
    Type: Grant
    Filed: March 31, 1993
    Date of Patent: August 1, 1995
    Assignee: AT&T Corp.
    Inventors: Jayant G. Hemmady, Craig P. Reilly, Neil J. Romy, Ronald A. Spanke, Douglas H. Yano
  • Patent number: 5438609
    Abstract: In a mobile communication method, when a terminating call is generated to a mobile station, position information about the mobile station as a called party and a mobile station identification number for paging the mobile station as the called party are retrieved on the basis of a mobile station terminating dial number from a station as a calling party. A local switch located in a local service area corresponding to a position indicated by the retrieved position information is determined. One subscriber line dial number, to which terminating connection is to be performed, is selected from subscriber line dial numbers of a plurality of subscriber lines connected to the determined local switch. The selected subscriber line dial number is stored in correspondence with the retrieved mobile station identification number. A subscriber line indicated by the subscriber line dial number stored in correspondence with the mobile station identification number is reserved.
    Type: Grant
    Filed: May 19, 1994
    Date of Patent: August 1, 1995
    Assignee: NEC Corporation
    Inventor: Masahiko Yahagi
  • Patent number: 5436900
    Abstract: The invention relates to a multi transcoder for simultaneous coding/decoding of a plurality of traffic channels in a mobile radio communication system. The multi transcoder comprises several digital signal processors for time multiplex coding/decoding of several traffic channels. The invention also relates to a land system in which a switch is provided between the radio equipment of the base stations and transcoder equipment associated therewith.
    Type: Grant
    Filed: September 23, 1993
    Date of Patent: July 25, 1995
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventors: Claes L. Hammar, Walter Ghisler, Gunnar Burstrom, Per J. H. Tjernlund
  • Patent number: 5437057
    Abstract: Near field coupling is employed for transferring data back and forth between base stations and portable stations in cellular communication systems, such as cellular local area networks.
    Type: Grant
    Filed: December 3, 1992
    Date of Patent: July 25, 1995
    Assignee: Xerox Corporation
    Inventors: Edward A. Richley, Lawrence Butcher
  • Patent number: 5436955
    Abstract: A compatible analog channel unit for a digital cellular telephone system services both analog and digital mode subscribers on the same system hardware. The analog channel unit which may be configured by the service provider to permit easy upgrading of service during the life of the equipment without additional capital expense to the service provider. All analog system functions required of an analog cellular base station are provided in firmware and executed on commercial digital signal processors (DSPs). The same DSPs, when down-loaded with different firmware, perform TDM/TDMA related functions as required of a digital cellular base station. A system operator can configure channel units from a remote location by simply downloading the appropriate firmware. The channel unit firmware, whether analog or digital, is downloaded into the system hardware according to the assigned mode. This permits dynamic channel allocation according to system requirements.
    Type: Grant
    Filed: July 30, 1993
    Date of Patent: July 25, 1995
    Assignee: Hughes Aircraft Company
    Inventors: John D. Kaewell, Jr., David M. Cooley
  • Patent number: 5437053
    Abstract: An apparatus stores a plurality of mobile identification numbers. When a user selects at least one of the stored mobile identification number and the apparatus receives a mobile identification number transmitted from a base unit, the received mobile identification number is compared to each selected mobile identification number. When the user does not select any of the stored mobile identification numbers and the apparatus receives a mobile identification number transmitted from the base unit, the received mobile identification number is compared to each of the stored mobile identification numbers. When the received mobile identification number coincides with one of the selected mobile identification number or one of the stored mobile identification numbers, the apparatus is enabled to communicate with the base unit.
    Type: Grant
    Filed: January 28, 1993
    Date of Patent: July 25, 1995
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Buntaro Sawa, Kuniyoshi Marui, Katsumi Shitara, Shinji Takachi
  • Patent number: 5437054
    Abstract: A method of assigning and sharing channels in a cellular communications system having a plurality of cells forming a plurality of cell clusters of size N. Each cell has at least one base station capable of sending and receiving signals and each cell has a plurality of adjacent cells. A plurality of distinct channels are allotted for use by the system and divided into N groups which are assigned among the N cells of each cell cluster so that each cell cluster has a substantially similar assignment of distinct channel groups. Each group of distinct channels is divided into a plurality of channel subgroups wherein each subgroup of channels of a cell substantially corresponds to an adjacent cell. The subgroups of channels are respectively designated for borrowing by cells adjacent to a corresponding cell. When all of the channels assigned to a cell are utilized, a channel can be borrowed at limited transmitted power, from a corresponding subgroup of channels of an adjacent cellular gateway.
    Type: Grant
    Filed: February 5, 1993
    Date of Patent: July 25, 1995
    Assignee: The Research Foundation of State University of New York
    Inventors: Stephen S. Rappaport, Hua Jiang
  • Patent number: 5434854
    Abstract: A system and method for delivering packetized data representing radio signals to and from cell sites, and to and from a destination point via a fast packet network. Each cell site includes an interface for packetizing the radio signals and transmitting the packetized data to its destination. The destination could be a delivery point at a switch connected to the telephone network, which then converts the packetized data into a form usable by the telephone network. Alternatively, the destination point could be another cell site, which then depacketizes the radio signal and retransmits the radio signal to another wireless communication device without connecting to the telephone network.
    Type: Grant
    Filed: December 27, 1993
    Date of Patent: July 18, 1995
    Assignee: AT&T Corp.
    Inventors: Joseph P. Focarile, Jayant G. Hemmady, Ronald A. Spanke, Hsien-Chuen Yu
  • Patent number: 5434798
    Abstract: A method and apparatus for performing reconfiguration of a cellular network is provided. Cell parameters of affected mobile switching centers in the network are copied to a database, and the copied parameters are stored. A set of proposed changes to the stored parameters are prepared and the consistency of the prepared set of proposed changes is verified. Any necessary alterations to the set of proposed changes responsive to the verification are made and the verified set of proposed changes are copied to the affected mobile switching centers. The verified set of proposed changes are then introduced into the network. Additionally, at all times, an up-to-date image of all the cell parameters in all the mobile switching centers in the network is maintained in a system parameter database.
    Type: Grant
    Filed: May 23, 1991
    Date of Patent: July 18, 1995
    Assignee: Telefonaktiebolaget L M Ericcson
    Inventors: Monica B. K. Madebrink, Walter Ghisler, Ake L. Ramstedt, Anders C. E. Hoff, Sven G. Nordstrom, Gunilla A. Bergling, Nils P. Taylor, Bo G. Svensson, Lars R. Waerme, Hans J. Roxbergh, Jan E. A. S. Dahlin, Harald Kallin
  • Patent number: 5432840
    Abstract: A method and a system for connecting a stationary subscriber apparatus selectively to a mobile subscriber apparatus through a telephone subscriber exchange, which includes a call switching function, by means of which incoming calls can be transferred, and which is connected to a number of stationary subscriber apparatus included in the telephone system and a number of mobile subscriber apparatus also included in said system, and computer apparatus included in the switchboard, in response to a call from a stationary subscriber apparatus to a telephone number relating to a plurality of mobile subscriber apparatus, for instance a group number. Upon receipt of a call, the telephone switchboard or subscriber exchange and the computer apparatus ascertain or establish the geographical area and/or geographical location of the stationary subscriber apparatus of each mobile telephone apparatus that is marked unoccupied, wherein the call received is transferred to the selected mobile subscriber apparatus.
    Type: Grant
    Filed: May 18, 1993
    Date of Patent: July 11, 1995
    Inventor: Leif C. Ryden
  • Patent number: 5432780
    Abstract: A cellular radiotelephone communication system cell site equipment is provided. The cell site equipment includes a radio frequency transmitter operating as one signal frequency source. In addition, the cell site equipment includes a first and a second signal combiner device tuned to a first and a second signal frequency, respectively. Further, the cell site equipment includes a radio frequency switching mechanism, operatively coupled to the radio frequency transmitter, the first signal combiner device, and the second signal combiner device, for coupling the radio frequency transmitter to either of the first and the second signal combiner devices. In one embodiment, each signal combiner device includes a resonant cavity for isolating a signal frequency source from other signal frequency sources and a coupling for coupling the isolated signal frequency source to a common transmitter output.
    Type: Grant
    Filed: April 19, 1993
    Date of Patent: July 11, 1995
    Assignee: Motorola, Inc.
    Inventors: John M. Smith, James F. Long, Ronald J. Wanat, Anthony Kobrinetz
  • Patent number: 5432841
    Abstract: A vehicle location system which provides a plurality of cellular systems that each includes a memory for identifying the cellular subscriber stations that are based in the particular system and visiting cellular subscriber stations based in another of the systems. The plurality of cellular systems include a roaming network that interconnects and transfers data in the memory relative to the presence of home and visiting cellular subscriber stations in the systems. An interface computer is provided to interconnect with at least one of the plurality of cellular systems. The interface computer accesses data in the roaming network relative to predetermined cellular subscriber stations.
    Type: Grant
    Filed: July 10, 1992
    Date of Patent: July 11, 1995
    Inventor: Neil A. Rimer
  • Patent number: 5430761
    Abstract: A method of reducing interference within a cellular system (10) by partitioning a designated frequency spectrum within a service coverage area (.0.1, .0.2, or .0.3) into a first and at least second spectrum inclusive of the designated frequency spectrum, each with an associated power level, and offsetting the spectrums for each TDM frame under the control of an offset number unique to each TDM frame. Assignment of communication units to a spectrum and power level are based upon distance from the base site (as determined through signal strength measurements). The spectral content of spectrums in adjacent service coverage areas is adjusted to include non-coincidental frequencies.
    Type: Grant
    Filed: May 27, 1994
    Date of Patent: July 4, 1995
    Assignee: Motorola, Inc.
    Inventors: Eugene J. Bruckert, Michael D. Kotzin
  • Patent number: 5430789
    Abstract: A cellular mobile base station apparatus comprises a first plurality of transceivers operating in a first radio frequency range assigned to a first cell and receiving power from a first power supply unit, a second plurality of transceivers operating in a second radio frequency range assigned to a second cell and receiving power from the first power supply unit, a third plurality of transceivers operating in the first radio frequency range and receiving power from a second power supply unit, and a fourth plurality of transceivers operating in the second radio frequency range and receiving power from the second power supply unit. The outputs of the first and third pluralities of transceivers are combined and transmitted from a first antenna and a signal in the first frequency range received by the first antenna is decomposed into first frequency range individual signals and applied to the first and third pluralities of transceivers.
    Type: Grant
    Filed: November 4, 1993
    Date of Patent: July 4, 1995
    Assignee: NEC Corporation
    Inventor: Naoto Ohgami
  • Patent number: 5430790
    Abstract: The present invention relates to a method and apparatus for enabling RT subscribers (15, 25 and 35), in radio service areas (1, 2 and 3) serviced by a radio telephone control system (11, 21 and 31) (RTCS), to receive calls originally presented to non-servicing RTCSs (11, 21 or 31). In this effort the RTCS (11) currently serving the RT subscriber (15) receives information and a callback number indicating that a call, placed to the RT subscriber (15), is in progress at a remote RTCS (21 or 31). In response, the currently serving RTCS (11) pages the RT subscriber (15). Thereafter, upon receipt of the RT subscriber's page response, the currently serving RTCS (11) calls the callback number so as to connect the RT subscriber (15) to the call in progress.
    Type: Grant
    Filed: June 13, 1994
    Date of Patent: July 4, 1995
    Assignee: Motorola, Inc.
    Inventor: James M. Williams
  • Patent number: 5430889
    Abstract: An automatic power control system for a cellular mobile radio system, comprising: a control center via which a plurality of base stations, each serving a cell, are linked to facilitate mutual communication between mobile units which gain access to the cellular mobile radio system via the base stations; at least two mobile units distinguishable by identification codes, the mobile units being arranged to transmit, in addition to an identification code unique to each mobile unit, a data sequence common to each mobile unit, but transmitted by each mobile unit at a nominally different time within each burst; each of said the stations including correlator operative to discriminate between signals from mobile units within its own cell and interfering signals from mobile units in adjacent cells and a data logger; and a data processing unit located at the control center and arranged to merge data from the data loggers located at each of the base stations, which serves to store the results of correlation of the data se
    Type: Grant
    Filed: August 27, 1993
    Date of Patent: July 4, 1995
    Assignee: Roke Manor Research Limited
    Inventors: Anthony P. Hulbert, David P. Chandler
  • Patent number: 5428666
    Abstract: A mobile radio-telephones having a plurality of number assignment modules ("NAM's") selects automatically one of the NAM's for use for communication. In a preferred embodiment, the mobile radio-telephone attempts to match system identification data in received control signals with system identification data stored in the NAM's, and, on encountering a match, will use the NAM containing the matched system identification for telephone communication.
    Type: Grant
    Filed: August 16, 1994
    Date of Patent: June 27, 1995
    Assignee: NovAtel Communications, Ltd.
    Inventors: Kipling W. Fyfe, Susan McIntyre
  • Patent number: 5428668
    Abstract: Transceiver frequency and optionally power level are allocated to a radio personal communications system which includes a base station connected to a wire telephone network and a cellular terminal operating within a region of a wide area cellular network to minimize interference between communications over the wide area cellular network and communications between the base station and the cellular terminal. The same cellular terminal may thus be used to communicate over the lower cost wire network when within range of the base station and over the wide area cellular network otherwise. The frequency for communications between the cellular terminal and the base station are optionally assigned by the operator of the wide area cellular network so appropriate frequencies and power levels can be assigned for base stations, to minimize same channel interference with the wide area cellular network.
    Type: Grant
    Filed: November 4, 1993
    Date of Patent: June 27, 1995
    Assignee: Ericsson GE Mobile Communications Inc.
    Inventors: Paul W. Dent, Jacobus C. Haartsen
  • Patent number: 5428817
    Abstract: In a mobile communication system where a service area is divided into a plurality of coverage areas defined by a plurality of mobile base stations, at least one of the shape and size of the coverage areas is changed in accordance with a number of mobile stations being serviced within each of the coverage areas, so that such a number of mobile stations is brought within a predetermined range.
    Type: Grant
    Filed: June 8, 1993
    Date of Patent: June 27, 1995
    Assignee: NEC Corporation
    Inventor: Masahiko Yahagi
  • Patent number: 5428665
    Abstract: In a Mobile Services Switching Center/Visitor Location Register (MSC/VLR), requests (made by a mobile station (MS)) for supplementary services may require processing only by the MSC/VLR, or they may require processing by a Home Location Register (HLR). A method of managing supplementary service procedures that are processed by an HLR includes supplying the MSC/VLR with a list containing only those supplementary service operations that shall be terminated in the MSC/VLR. In the MSC/VLR, a forward direction message is received from an MS, the forward direction message including an intended supplementary service operation. Then, the intended supplementary service operation is compared with the list of supplementary service operations. If the intended supplementary service operation is contained in the list of supplementary service operations, then the intended operation is terminated in the MSC/VLR.
    Type: Grant
    Filed: October 26, 1993
    Date of Patent: June 27, 1995
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventor: Sven J. Lantto
  • Patent number: 5428815
    Abstract: Geographic reuse of frequencies within a multisite communication system are dynamically altered as a function of communication unit type. Since some communication unit types pose a smaller risk of interference, increased geographic reuse can be tolerated. Similarly, reuse can be diminished to accommodate communication unit types that pose a significant risk of interference over a wide geographic area.
    Type: Grant
    Filed: April 30, 1991
    Date of Patent: June 27, 1995
    Assignee: Motorola,Inc.
    Inventor: Gary W. Grube
  • Patent number: 5428667
    Abstract: A multi-channel cellular communications intercept system for monitoring and then intercepting communications between a mobile unit and a base station in one cell of a cellular telephone system. The system includes a controller and a plurality of receivers with each receiver monitoring the forward control channel from a different cell within a geographical area of interest. When a global page for a target mobile unit is received, one of the receivers in the system is retuned to the forward voice communication channel on which the target mobile unit will be broadcasting for the purpose of monitoring and/or recording the conversation. The remaining receivers are retuned to the strongest forward control channels in the area.
    Type: Grant
    Filed: March 11, 1993
    Date of Patent: June 27, 1995
    Assignee: Harris Corporation
    Inventors: Scott D. Easterling, Michael O. Linden, John C. Voelkel
  • Patent number: 5425031
    Abstract: A multiplex audio signal from an exchange apparatus is demultiplexed by a first multiplexer/demultiplexer into demultiplexed signals that are supplied to a first switch circuit which switches between transmission paths to apply the demultiplexed signals to a plurality of audio coding circuits. Certain output signals from the audio coding circuits are supplied to a second switch circuit, time-division-multiplexed, and applied to the first switch circuit. The multiplexed signal is outputted from the first switch circuit for transmission in a given time slot over a radio communication path.
    Type: Grant
    Filed: November 29, 1993
    Date of Patent: June 13, 1995
    Assignee: NEC Corporation
    Inventor: Shigeru Otsuka
  • Patent number: 5425051
    Abstract: Improved apparatus for a radio communication network having a multiplicity of mobile transceiver units selectively in communication with a plurality of base transceiver units which communicate with one or two host computers for storage and manipulation of data collected by bar code scanners or other collection means associated with the mobile transceiver units. The radio network is adaptive in that in order to compensate for the wide range of operating conditions a set of variable network parameters are exchanged between transceivers in the network. These parameters define optimized communication on the network under current network conditions. Examples of such parameters include: the length and frequency of the spreading code in direct-sequence spread spectrum communications; the hop frame length, coding, and interleaving in frequency-hopping spread spectrum communications; the method of source encoding used; and the data packet size in a network using data segmentation.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: June 13, 1995
    Assignee: Norand Corporation
    Inventor: Ronald L. Mahany
  • Patent number: 5425076
    Abstract: A testing system for wireless communication networks, particularly cellular networks, having a test set located in a cell site which communicates through the cell's base station to a responder at the mobile telephone switching office (MTSO). The test set, which includes a measurement module, controller, modem, and cellular phone, initiates the call to the responder, and directs the responder to transmit and receive certain test signals which are then measured by the measurement module. The tests preferably include standard "105" tests. The test set, which may be fixed or mobile, provides essentially continuous monitoring of voice channels within a given cell, and can send an alarm in near real-time to the network control center when a faulty voice channel is detected.
    Type: Grant
    Filed: June 30, 1992
    Date of Patent: June 13, 1995
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Gary H. Knippelmier
  • Patent number: 5422932
    Abstract: A cellular system uses dynamic repartitioning and channel packing to improve capacity without impacting quality. Dynamic repartitioning is employed to convert a carrier which operates, at one time, as an analog carrier to operate, at a later time, as a digital carrier in response to changes in offered traffic. Alternatively, a carrier which, at one time, operates as a digital carrier is converted to operate, at a later time, as an analog carrier in response to changes in offered traffic. The system also supports multiple digital protocols so that a carrier can also be converted to operate in any one of several different digital modes. Channel packing is used to allocate as many digital channels as possible to as few digital carriers as possible. In a preferred embodiment, both repartitioning and channel packing are implemented in response to a request for a channel allocation or deallocation.
    Type: Grant
    Filed: April 25, 1994
    Date of Patent: June 6, 1995
    Assignee: Hughes Aircraft Company
    Inventors: Stanley Kay, George D. Farmer, Hans Bhatia, Ashok D. Mehta, Christopher J. Kain, Nick Sampson
  • Patent number: 5422930
    Abstract: A radio frequency communication system is coupled to a telephone network (130) having automatic number identification (ANI) capabilities for communication thereover. The radio frequency communication system includes at least one relocateable base station (115) which shares a radio frequency channel with stationary communication devices (105) for communicating over predetermined geographic areas (110). The radio frequency communication system further includes a service center (125) which, in response to a call from a base station (115), receives from the telephone network (130) information indicative of at least a portion of a telephone number from which the base station (115) is calling. The service center (125) determines therefrom whether the base station (115) is located within any of the predetermined geographic areas (110).
    Type: Grant
    Filed: May 20, 1993
    Date of Patent: June 6, 1995
    Assignee: Motorola, Inc.
    Inventors: James A. McDonald, Ross Ruthenberg
  • Patent number: 5423060
    Abstract: A method of remote-registering a telephone number or similar communication control information at a mobile station such as an automobile telephone, and circuitry therefor. The mobile station is conditioned for a remote register mode in response to a command signal which is transmitted from a remote station. A modulated multifrequency signal corresponding to the modulated communication information is sent from the remote station to the mobile station which is in the remote register mode over a communication channel. The mobile station demodulates the modulated multifrequency signal to produce the original multifrequency signal, converts the demodulated multifrequency signal to a digital signal, and then stores the digital signal in a memory.
    Type: Grant
    Filed: June 5, 1991
    Date of Patent: June 6, 1995
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Yoshio Masuda, Kouji Wada
  • Patent number: 5423062
    Abstract: In a system for reducing congestion of a radio paging channel, a radio base station has a radio paging channel for connection with a radio telephone. A first announcement section makes reception announcement for requesting a calling number and a called number to a calling subscriber in response to an incoming call for a call-back automatic announcement service from the calling subscriber. A registering section registers the calling and called numbers informed from the calling subscriber. A monitoring section monitors congestion of the radio paging channel of the radio base station, and outputs a detection signal when a usage of the radio paging channel becomes lower than a preset level. An outgoing call control section generates an outgoing call to a called subscriber in response to the detection signal from the monitoring section on the basis of the called number registered in the registering section.
    Type: Grant
    Filed: August 31, 1993
    Date of Patent: June 6, 1995
    Assignee: NEC Corporation
    Inventor: Yukinori Sakakura
  • Patent number: 5423063
    Abstract: A method and apparatus identifies (810) communication cells (500) in a simulcast radio communication system (100) comprising the cells (500) and a portable communication unit (PCU) (108). Identification bit .patterns (602, 604, 606) are assigned (802) to the cells (500) in a manner such that when transmissions of the identification bit patterns are received simultaneously from cells (500) adjacent to one another, thereby producing a received interference bit pattern (708), identities of the cells (500) received can be resolved to a subset of the cells (500) by analysis of the received interference bit pattern (708), wherein the subset is inclusive of the cells (500) received.
    Type: Grant
    Filed: August 27, 1993
    Date of Patent: June 6, 1995
    Assignee: Motorola, Inc.
    Inventor: Steven J. Goldberg
  • Patent number: 5423056
    Abstract: An adaptive paging system includes a paging terminal that is operable to receive paging signals and transmit them up to a satellite (28) and down through a downlink (312) to stick locations (314), (316), (318), (320) and (322). Each of the sticks (314)-(322) is associated with a given locale (324), (326), (328), (330) and (332). The sticks are operable in a simulcast mode and also in a cellular mode. In the cellular mode, each of the sticks (314)-(322) is operable to receive a separate message that is distinct from the other cells. Pagers (36), having a known location at any of the locales (324)-(332) can then be selectively addressed and data transferred thereto. To prevent interference between adjacent RF locales, adjacent cells are not turned on during transmission to select cells in the cellular mode. These can be turned on at a different time. Orthogonal coding can be utilized such that adjacent cells can be turned on, thus increasing throughput.
    Type: Grant
    Filed: May 2, 1994
    Date of Patent: June 6, 1995
    Assignee: Pagemart, Inc.
    Inventors: Roger D. Linquist, Malcolm M. Lorang
  • Patent number: 5422931
    Abstract: A dual mode, portable cellular telephone utilizes an rf switch to control the rf signal path through its rf output stage. A voltage controlled oscillator (VCO) generates an rf signal that is selectively modulated with an fm modulation signal. In an FM modulation mode, the rf signal generated by the VCO is amplified by a first rf amplifier and a second rf amplifier, and then applied to a power amplifier. The power amplifier couples the amplified rf signal to an antenna for broadcasting. A first rf signal path through the rf output stage thus includes the VCO, first rf amplifier, second rf amplifier, and power amplifier, and the resulting rf output signal is FM modulated. In a digital modulation mode, the rf signal generated by the VCO is unmodulated, having a fixed frequency. This is achieved by making the fm modulation signal be a constant signal. The fixed frequency signal is amplified by the first rf amplifier and then applied to a digital modulator as a local oscillator signal.
    Type: Grant
    Filed: September 22, 1993
    Date of Patent: June 6, 1995
    Assignee: Hughes Aircraft Company
    Inventors: Phyllis Austin-Lazarus, Brian Shirk
  • Patent number: 5422935
    Abstract: A method and apparatus is provided for locally routing calls in a communication system. The method and apparatus provide PSTN interconnects (N, P, Q,) at each of the base station controllers (11, 14) and at the mobile switching center (12). A control intercept (13) intercepts PSTN command information being communicated between the mobile switching center (12) and the base station controllers (11, 14), and routes the PSTN command information to a PSTN interconnect (N, P) at a base station controller (11, 14) when local call service is required.
    Type: Grant
    Filed: July 13, 1993
    Date of Patent: June 6, 1995
    Assignee: Motorola, Inc.
    Inventor: Stephen L. Spear
  • Patent number: 5420863
    Abstract: In a TDMA cellular mobile communication system, incoming signals from the public switched network are converted by speech coder/data compressor units of a MTSO (mobile telephone switching office) to low-bit-rate signals and combined into a first TDM signal for transmission to a base station. The components of the first TDM signal are respectively routed according to a channel assignment signal and fed into desired modulators which are periodically activated according to the channel assignment signal to transmit signals on assigned channels to mobile units. Signals from the mobile units are received by demodulators at the base station and combined into a second TDM signal which is transmitted to the MTSO. The components of the second TDM signal are routed according to the channel assignment signal to appropriate speech decoder/data expander units for conversion to the original high-bit-rate signals for transmission to the network.
    Type: Grant
    Filed: July 9, 1993
    Date of Patent: May 30, 1995
    Assignee: NEC Corporation
    Inventors: Masanori Taketsugu, Yukitsuna Furuya
  • Patent number: 5420910
    Abstract: A method and apparatus for fraud control in cellular telephone systems. Call records from a switch are scanned to identify a fraudulent cellular phone based on its behavior. An identifier, e.g., a radio frequency (RF) signature, representative of the fraudulent phone is stored in a control channel editor at a cell site. A database of identifiers may comprise a positive validation database storing the identifiers for all valid phones used in the cellular telephone system, or it may be a negative validation database storing the identifiers for known fraudulent phones. A control channel editor intercepts a call origination request transmitted by a phone, and a control processor compares one or more characteristics of the phone transmitting the call origination request to the database of identifiers. The control processor then prevents the call origination request from completing when the comparison indicates that the phone is fraudulent.
    Type: Grant
    Filed: June 29, 1993
    Date of Patent: May 30, 1995
    Assignee: AirTouch Communications
    Inventors: Ronald S. Rudokas, John A. Storch, David L. Daniels
  • Patent number: 5420911
    Abstract: The present invention is directed to a cellular mobile radio telephone system in which mobile stations may select either analog or digital control channels. Analog and dual-mode mobile stations are equipped to become multi-mode mobile stations which monitor both analog and digital control channels depending on the selected mode. Downlink multi-mode mobile stations, while required to use analog control channels for call access, may nonetheless scan digital control and paging channels to receive downlink control and paging communications from the land-based system. Bi-directional multi-mode mobile stations have the same capabilities as downlink mobiles but also are equipped to transmit control information to the land station over the uplink digital control channel. If no digital control channel is available, the multi-mode mobile stations scan primary and secondary sets of analog control channels.
    Type: Grant
    Filed: October 4, 1993
    Date of Patent: May 30, 1995
    Assignee: Telefonaktiebolaget L M Ericsson
    Inventors: Jan E. A. S. Dahlin, Walter G. A. Mueller, Walter Ghisler
  • Patent number: 5418843
    Abstract: A method is employed for estimating traffic density in a mobile telephone network. A specialized measuring mobile unit which is capable of determining its own position independently of the system is allowed to pass through relevant traffic routes during which time the measuring mobile station transmits a radius signal as well as its position to the various fixed measuring stations. The signal strength received from the measuring mobile station is recorded synchronously with the aid of a number of suitably cited measuring base stations. The measuring values from the measuring stations are compiled with the respective registered positions so that an unambiguous relationship between the signal strength values and the position of a mobile station passing through the entire system is obtained. An actual traffic is then measured with the aid of the measuring station and the measurement results thereof are related to the geographic positions so that a topographic distribution of the traffic density is obtained.
    Type: Grant
    Filed: February 10, 1994
    Date of Patent: May 23, 1995
    Assignee: Televerket
    Inventor: Paul Stjernholm
  • Patent number: 5416797
    Abstract: A system and method for communicating information signals using spread spectrum communication techniques. PN sequences are constructed that provide orthogonality between the users so that mutual interference will be reduced, allowing higher capacity and better link performance. With orthogonal PN codes, the cross-correlation is zero over a predetermined time interval, resulting in no interference between the orthogonal codes, provided only that the code time frames are time aligned with each other. In an exemplary embodiment, signals are communicated between a cell-site and mobile units using direct sequence spread spectrum communication signals. In the cell-to-mobile link, pilot, sync, paging and voice channels are defined. Information communicated on the cell-to-mobile link channels are, in general, encoded, interleaved, hi-phase shift key (BPSK) modulated with orthogonal covering of each BPSK symbol along with quadrature phase shift key (QPSK) spreading of the covered symbols.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: May 16, 1995
    Assignee: Qualcomm Incorporated
    Inventors: Klein S. Gilhousen, Irwin M. Jacobs, Roberto Padovani, Lindsay A. Weaver, Jr., Andrew J. Viterbi
  • Patent number: 5412659
    Abstract: Within a cell of a TDMA mobile communication system, each mobile station transmits a control message on an up-link frame. On receiving it, the base station determines if the message quality is affected during transmission. A corruption status indication is stored into a position of a frame status memory corresponding to the up-link frame if the message quality is low. When the base station detects a frame identification contained in the received message, it erases the corruption status indication stored in a position identified by the detected frame identification, and transmits a control message on a down-link frame, containing the result of the quality determination. In response, the mobile station stores the identification of the frame of the message into a collision memory, and retransmits a copy of the up-link control message containing the frame identification.
    Type: Grant
    Filed: October 25, 1993
    Date of Patent: May 2, 1995
    Assignee: NEC Corporation
    Inventors: Masashi Fujita, Toshitaro Harada
  • Patent number: 5412375
    Abstract: In a communication system having a plurality of air interfaces, one of the air interfaces is assigned for use for a desired communication by transmitting a message, having a list of air interface capabilities of the subscriber, from the subscriber to a base (12). A list of air interface capabilities of the base is then compared, at a controller, with the list from the subscriber (14). A compatible air interface, or list of compatible air interfaces, is generated by the controller and provided to the base (15, 31). The base will then direct the subscriber to access the communication system utilizing a compatible air interface (18, 35).
    Type: Grant
    Filed: September 27, 1993
    Date of Patent: May 2, 1995
    Assignee: Motorola, Inc.
    Inventor: Daniel E. Wood
  • Patent number: 5410752
    Abstract: A method and apparatus for combining multiple MFR subnetworks (15) and SFR subnetworks (17) to provide seamless data communications throughout a geographic area (13) wherein a portable station (61) receives a first data message stream (101) for a first time period (153) that exceeds a retransmission interval (115) and under appropriate data path quality conditions monitors a second data message stream (121 ) for a second time period (155) that is less than the retransmission interval (115) to identify alternative data paths with acceptable quality conditions that may be used for further data message delivery to the portable station (61 ).
    Type: Grant
    Filed: September 30, 1992
    Date of Patent: April 25, 1995
    Inventor: Christopher Scholefield
  • Patent number: 5410737
    Abstract: A frequency agile sharing technology (FAST) system for controlling frequent usage in a communications system is disclosed. Specifically, a frequency agile sharing technology system of controlling frequency usage and eliminating interference for use with a Personal Communications Service (PCS) System is described. The frequency control system allows PCS systems to coexist in the same frequency band as Private Operational Fixed Microwave Service (POFS) systems without mutual interference. This system also controls frequency usage within a PCS system to eliminate interference from within the PCS system. This interference elimination system combines theoretical radio frequency interference analysis with measurements of actual frequency usage and allows for efficient and coordinated dynamic frequency allocation planning and management.
    Type: Grant
    Filed: April 27, 1992
    Date of Patent: April 25, 1995
    Assignee: American PCS L.P.
    Inventor: J. Barclay Jones
  • Patent number: 5410736
    Abstract: A method for conducting radio transmission systems interference studies based on the prior art two-step process of conducting a simple analysis on all potentially interfering systems to eliminate those clearly not causing interference into radio receiver under study, and then conducting a detailed analysis on the remaining systems. The new method replaces the first step in the prior art system with a method using pre-calculated average terrain elevations over a geographic block for determining whether the loss should be calculated using a smooth terrain calculation method with a simulated single knife edge diffraction obstacle in the path, or a rough terrain calculation method that substitutes a pre-calculated block roughness factor in place of the path roughness factor, and then also substitutes a new effective antenna height for the actual antenna height in the propagation loss calculations.
    Type: Grant
    Filed: June 3, 1993
    Date of Patent: April 25, 1995
    Assignee: Bell Communications Research, Inc.
    Inventor: Mahbub U. Hoque
  • Patent number: 5410538
    Abstract: A method of transmitting signals from a mobile unit to a base station in the reverse link direction using multi-tone techniques includes the step of dividing a frequency band into a plurality of generally even spaced tones. The tones are partitioned into a predetermined number of tone sets which each contain a predetermined number of tones. Each unit within a given sector is assigned a tone set for transmitting information signals. The tones within each tone set are selected so that the modulated signals transmitted by each unit are orthogonal with respect to all other tone sets assigned to units in that sector. Adjacent cells have no more than one tone in common.
    Type: Grant
    Filed: November 9, 1993
    Date of Patent: April 25, 1995
    Assignee: AT&T Corp.
    Inventors: James R. Roche, Aaron D. Wyner
  • Patent number: 5410732
    Abstract: Methods and apparatus are set forth which enable a radio frequency data communications network (1) to perform decentralized uplink network control functions (decentralized away from the centralized general communications controller (GCC) level of the network hierarchy); (2) to minimize, or in some cases eliminate, the overhead expended in making power lever (signal strength) determinations and assessments at both the GCC and base station levels of the network hierarchy (for the purpose of managing uplink communications); and (3) to allow individual subscriber radios (terminals) to dynamically determine the most desirable base station to communicate with when exchanging information a host computer via a shared RF communication channel (the link between a terminal and the base station).
    Type: Grant
    Filed: August 19, 1993
    Date of Patent: April 25, 1995
    Assignee: International Business Machines Corp.
    Inventors: Richard N. Ames, Victor S. Moore