Using Time Division Multiplexing Patents (Class 370/314)
  • Patent number: 6512748
    Abstract: A radio paging signal coding control scheme capable of improving the reception characteristic of the receiver by carrying out a coding control to determine logical channels for accommodating paging signals such that the transmission rate equivalently becomes as low as possible according to the paging signal traffic, without interrupting the paging signal coding processing while maintaining the combination of transmission rate and modulation scheme for frames, is disclosed. In the case of using prescribed transmission rate and N-valued modulation scheme, logical channels to be used for transmission of paging signals among a plurality of available logical channels are determined by setting priority orders among a plurality of available logical channels such that a number of states of modulated signals becomes less than N when paging signal traffic is small.
    Type: Grant
    Filed: January 28, 1999
    Date of Patent: January 28, 2003
    Assignee: NTT Mobile Communications Network Inc.
    Inventors: Takayuki Mizuki, Setsuya Ohashi, Yasushi Yamao, Shogo Ito
  • Publication number: 20030002451
    Abstract: A method for transferring data between at least one read/write device (RWD) and at least one mobile data memory (MDM) in an identification system, using at least one mobile data memory (MDM) that is attached to an object for recording object-related status and/or process data, e.g., in a dispatch, transport and/or manufacturing system for the individual items. According to the method, a time-slot structure for transferring data to the mobile data memory (MDM) is predetermined in the read/write device (RWD).
    Type: Application
    Filed: June 10, 2002
    Publication date: January 2, 2003
    Applicant: SIEMENS AKTIENGESELLSCHAFT
    Inventors: Wolfgang Konrad, Wolfgang Pusch, Martin Schiefer, Peter-Ernst Veith
  • Patent number: 6501744
    Abstract: A slotted communication mode employed in a wireless code division multiple access (CDMA) communication system includes slotted frames interspersed among normal frames, each slotted frame containing a slot during which a measurement of signal quality of transmission at a different candidate operating frequency is made by the mobile station, a leading frame portion preceding the slot, and a trailing frame portion succeeding the slot. In order to mitigate an increase in bit error rate (BER) as a result of use of the slotted mode the spreading factor (SF) of data in the leading and trailing frame portions is set to a value which is greater than that of data in the normal frames. The increase of spreading factor of data in these frame portions may be accompanied by an increase in power level therein, as a further BER mitigating factor.
    Type: Grant
    Filed: December 22, 1999
    Date of Patent: December 31, 2002
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Henon Alexandre
  • Patent number: 6480477
    Abstract: A method and apparatus for a data transmission rate of multiples of 100 mega-bits per second (Mbps) in a terminal for a wireless metropolitan area network.
    Type: Grant
    Filed: October 23, 1998
    Date of Patent: November 12, 2002
    Assignee: Innowave ECI Wireless Systems Ltd.
    Inventors: Kirk Treadaway, Tat Huen, Tho Le Ngoc
  • Patent number: 6477151
    Abstract: A method of synchronising radio signal transmission slots at a mobile station to radio signal reception slots at a base station subsystem to account for a propagation delay between the mobile station and the base station subsystem. The method is applicable to a GPRS packet switched cellular telephone network in which a downlink channel is defined for transmitting user data from the base station subsystem to the mobile station and an uplink channel is defined for transmitting user data from the mobile station to the base station subsystem. These channels comprise dynamically allocated time slots in a time division multiple access frame. An updated timing advance value indicative of the radio propagation delay between the mobile station and the base station subsystem at a given time is calculated at the base station once every 8 multiframes. The timing advance value is identified to the mobile station by a timing advance index previously allocated to the mobile station.
    Type: Grant
    Filed: November 10, 1998
    Date of Patent: November 5, 2002
    Assignee: Nokia Mobile Phones Ltd.
    Inventor: Jarkko Oksala
  • Patent number: 6477382
    Abstract: A system and method including a flexible paging protocol which adjusts the allocation of resources for paging in response to the amount of actual paging traffic, by increasing resources for paging when paging traffic is heavy and decreasing them when paging traffic is light. A base station transmits a paging packet message over a paging broadcast channel containing a set of paging messages and a next page pointer. The next page pointer identifies when the next set of paging packet message will be transmitted. A user station monitoring the paging channel receives the next page pointer, and, if not being paged, goes to sleep until the next paging packet message is due. When paging traffic is light, paging messages are sent infrequently, freeing up base station resources and allowing the user station to remain asleep longer. When paging traffic is heavy, paging messages are sent more frequently, ensuring rapid response to the pages and reducing the probability of a missed call.
    Type: Grant
    Filed: June 12, 2000
    Date of Patent: November 5, 2002
    Assignee: Intel Corporation
    Inventors: Carl Mansfield, Izzet M. Bilgic, Benjamin K. Gibbs, Sherman L. Gavette
  • Patent number: 6470035
    Abstract: A receiver receives a signal transmitted by a time-division multi-access method that divides one frame into a plurality of communication slots in conducting communication. In this receiver, a detection circuit detects whether a received RF signal is stronger than a predetermined level. The received RF signal is demodulated by a demodulation circuit. An oscillation circuit generates a clock that is used to decode the data obtained by demodulation. The data obtained by demodulation is stored in a memory in synchronism with a clock reproduced from the received signal, and is then retrieved from the memory in synchronism with the clock generated by the oscillation circuit. This eliminates jitters. After jitter elimination, the data is decoded by a processing circuit. The writing/reading operation against the memory is initialized in accordance with a result output from the detection circuit.
    Type: Grant
    Filed: March 2, 1999
    Date of Patent: October 22, 2002
    Assignee: Rohm Co., Ltd.
    Inventor: Yasushi Kinugasa
  • Patent number: 6466569
    Abstract: Uplink transmission and reception techniques for a processing satellite including one or more earth terminals 400 connected to receive ATM data cells. One or more encoders 418 are connected to coordinate four data cells with an error correction code to generate data bursts and to coordinate the data bursts with synchronizing bursts to generate data frames. One or more modulators 420 are connected to modulate the data frames by frequency division multiple access modulation to enable placement of the modulated data frames into a plurality of channels. One or more antennas 406 transmit the modulated data frames to a satellite 100 over 48 beams with various forms of polarization. In satellite 100, a receiving multibeam antenna and feed 106 responds to one or more beams of radiocarrier signals having one or more forms of polarization. One or more demodulators 138 demodulate the radio carrier signals into data frames from various channels including a plurality of channel types.
    Type: Grant
    Filed: September 29, 1999
    Date of Patent: October 15, 2002
    Assignee: TRW Inc.
    Inventors: David A. Wright, Stuart T. Linsky, Donald C. Wilcoxson, Eldad Perahia, Gregory S. Caso
  • Publication number: 20020110093
    Abstract: A method is provided for background scanning in a selective call communication system (102) having a plurality of channels (110, 112,114), wherein a selective call device (104) has designated thereto one of an odd and even frame compulsory decoding schedule. The selective call device (104) decodes system configuration information (SCI) on odd SCI frames during the odd compulsory decoding schedule, scans for even SCI frames of target channels while maintaining the odd compulsory decoding schedule, and releases or maintains the odd compulsory decoding schedule based on the system configuration information found on the target channels.
    Type: Application
    Filed: December 15, 2000
    Publication date: August 15, 2002
    Inventors: Leonard E. Nelson, Douglas I. Ayerst
  • Patent number: 6429771
    Abstract: A messaging system transmits to a subscriber unit (122) on a plurality of channels (410) operating concurrently. The system transmits (1108) control information for the subscriber unit on a control channel assigned to the subscriber unit, and transmits (1110) a personal message fragment intended for the subscriber unit on a first channel. The system also transmits (1112) a group-call message fragment that may be intended for the subscriber unit on a second channel. Before transmitting, the system schedules (1106) the transmission such that the probability that the personal and group-call message fragments will overlap temporally with one another and that either of the fragments will overlap temporally with the control information is reduced.
    Type: Grant
    Filed: April 27, 1999
    Date of Patent: August 6, 2002
    Assignee: Motorola, Inc.
    Inventors: Jheroen Pieter Dorenbosch, Richard Lionel Bennett, Soeren Henrik Thomsen
  • Patent number: 6411614
    Abstract: A system includes a modem which receives a burst of a time division multiple access (TDMA) signal. A burst mode controller, connected to the modem, is operable to detect a unique word in the burst. If the unique word is not detected, the burst mode controller loads a predetermined bit pattern into a channel identifier field of the burst. The predetermined bit pattern indicates that a payload field of the burst contains voice data.
    Type: Grant
    Filed: October 30, 1998
    Date of Patent: June 25, 2002
    Assignee: National Semiconductor Corporation
    Inventor: David L. Weigand
  • Patent number: 6404748
    Abstract: A receipt circuit for a TDMA (Time Division Multiple Access) radio apparatus of the present invention includes a switch selectively turned on or turned off in order to remove a residual signal component occurring in a guard time between consecutive time slots due to the group delay of a SAW (Surface Acoustic Wave) filter or a ceramic filter. The receipt circuit therefore obviates the fall of receipt sensitivity even when a TDMA signal of low level is input immediately after a slot in which a TDMA signal of high level has been input. In addition, the receipt circuit is free from the erroneous detection of an input electric field.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: June 11, 2002
    Assignee: NEC Corporation
    Inventor: Futoshi Nakamura
  • Patent number: 6381713
    Abstract: In a digital communication system, a method is provided for recognizing and acting upon differences in information field characteristics when transmission errors are detected. Information having more than one field protected by a channel code is received and decoded according to the channel code. Based on the outcome of the decoding, fields of the information into which transmission errors fall are identified. These are called flawed fields. A characteristic of a flawed field is determined. The information is then processed according to the characteristic. In one embodiment of the invention, the syndrome of an incoming packet is computed. When the syndrome is all-zero, the packet is passed up a communication protocol stack conventionally. When the syndrome is not all-zero, the coset leader associated with the syndrome is found, and used to determine which fields of the packet are most likely flawed.
    Type: Grant
    Filed: May 11, 1999
    Date of Patent: April 30, 2002
    Assignee: Ericsson Inc.
    Inventors: David Rand Irvin, Ali S. Khayrallah
  • Publication number: 20020044067
    Abstract: A message system includes a message delivery device having a rendering device and a locating device for determining an indication of geographical location of the display. The message system also includes a capability for selecting or generating a message for the display from among a set of predefined or generated messages in response to the indication of geographical location and a timing parameter.
    Type: Application
    Filed: October 31, 1996
    Publication date: April 18, 2002
    Applicant: TECHNICAL VISIONS, INC.
    Inventor: KEVIN ILCISIN
  • Patent number: 6363058
    Abstract: A method for processing multiple data services over a communications link between a mobile station and a base station is disclosed. A RLC/MAC protocol layer of the communications link between a mobile station and a base station receives a plurality of radio bearer services each including at least one service provided by the mobile station. The plurality of radio bearer services are processed in such a manner that services having substantially similar quantity of signal requirements are combined for transmission on a single logical channel. Data within the transmission blocks may be prioritized to enable flexible control of transmission rates.
    Type: Grant
    Filed: April 15, 1998
    Date of Patent: March 26, 2002
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Christiaan Roobol, Johan Lundsjö, Mathias Johansson, Per Beming
  • Publication number: 20020035663
    Abstract: Data is written into a circular buffer at an address pointed to by a write pointer. A number is written into the address with the data. Each time the circular buffer is traversed by the write pointer this number increments modulo a predetermined number. This number makes the circular buffer appear longer than it really is and can be used to identify underruns. The buffer has application in a segmentation and reassembly device for ATM constant bit rate services.
    Type: Application
    Filed: September 13, 2001
    Publication date: March 21, 2002
    Inventors: Dawn Finn, George Jeffrey
  • Patent number: 6337854
    Abstract: A method of transmitting an initial message between two radiocommunication stations, possibly mobile stations, in which a first radiocommunication station: inserts a time supplied by a clock in the initial message to form an outgoing message, and transmits the outgoing message and the successive times supplied by the clock to the second radiocommunication station. Applications include railroad radiocommunication networks.
    Type: Grant
    Filed: January 5, 1999
    Date of Patent: January 8, 2002
    Assignee: Alcatel
    Inventors: Hélène Papini, François Simon
  • Patent number: 6335676
    Abstract: In a selective calling system where a selective calling signal is changeable in transmission rate, a radio selective call receiver includes first and second low-pass filters which are selectively used depending on a transmission rate of the selective calling signal. A data decision section performs data decision of the received signal passing through a selected low-pass filter according to a timing signal which is generated based on a predetermined phase shift amount of the received signal when a transmission rate is changed.
    Type: Grant
    Filed: May 11, 1998
    Date of Patent: January 1, 2002
    Assignee: NEC Corporation
    Inventor: Kazuhumi Gotoh
  • Patent number: 6097932
    Abstract: A radio selective calling receiver having a multiarea function includes a reception channel reception enable/disable information storage means. In a normal operation, only a specific frame is intermittently received using a predetermined first channel. When a synchronization signal is not received in a synchronization state wherein intermittent reception is being performed, the number of times of consecutive nonreception is counted. When the consecutive nonreception count has reached a predetermined value, it is determined that an out-of-area state is set. Before the consecutive nonreception count reaches the predetermined value, the synchronization signal of another frame different from the specific frame is received using another channel other than the first channel, and reception enable/disable information for the another channel is stored.
    Type: Grant
    Filed: December 9, 1997
    Date of Patent: August 1, 2000
    Assignee: NEC Corporation
    Inventor: Kazuhiro Kudoh
  • Patent number: 6091719
    Abstract: When a mobile station is to be called by a fixed terminal device as a caller side, incoming call information containing the intermittent receiving cycle of the mobile station and a mobile station number is sent from a control station to a radio base station. A paging slot received by the mobile station is obtained based the mobile station number and the intermittent receiving cycle. The incoming call information is written in a buffer corresponding to the obtained paging slot in a paging slot table section. A transmission processing section calculates products between intermittent receiving cycles and numbers of holding times. A priority order for transmission is decided based on the calculated products. The mobile station numbers are packed in a paging message starting from the information high in the priority order.
    Type: Grant
    Filed: August 7, 1997
    Date of Patent: July 18, 2000
    Assignee: NEC Corporation
    Inventors: Seiji Kondo, Hiroshi Ishiga
  • Patent number: 6091716
    Abstract: A method of producing a receive signal quality estimate in a subscriber unit (SU) located in a given geographic area covered by a wireless communication system of a kind in which a base station transmits downlink signals in a group of successive time frames directed to a set of geographic areas including an area in which the SU is located, wherein each of the group of successive time frames has signals aimed at a corresponding one of the set of geographic areas.
    Type: Grant
    Filed: July 1, 1998
    Date of Patent: July 18, 2000
    Assignee: Motorola, Inc.
    Inventors: Robert Mark Gorday, Gregory O. Snowden, Craig Christmas, Stuart Kreitzer, Kenneth C. Elkin, Leonard Bennett
  • Patent number: 6052364
    Abstract: A satellite communication system including a portable satellite terminal is provided which utilizes C/K.sub.u -band and spread spectrum technology to drastically reduce the antenna and terminal sizes. Both CDMA and time division multiplexing (TDM) are used to permit efficient all-digital voice, facsimile and data operations in either full mesh or star modes. A single Network Controller can handle both Star and Mesh mode traffic on the same or several transponders. Narrowband CDMA/frequency division multiple access is used for inbound transmission from the terminal while outbound transmissions from the hub utilize TDM/FDMA. Furthermore, the system is scalable in fixed bandwidth increments to support network size evolution. All signalling for call setup and takedown is done in-band on the same carrier that is used for the traffic, thereby eliminating the need for a separate signalling channel and frequency retuning.
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: April 18, 2000
    Assignee: Comsat Corporation
    Inventors: Harvey Chalmers, Ajit Shenoy
  • Patent number: 6023231
    Abstract: In a selective call receiver with a display and a DTMF transmitter, a limit length of transmission message is set and a transmission message is displayed such that a first part of the message which is not longer than the limit length is displayed in a first image and a second part thereof exceeding the limit length is displayed in a second triage different from the first image. After transmitting the first part of the message through the transmitter, a predetermined indicator is displayed on screen for indicating that the second part is left without transmitted before transmitting the second part depending on a transmission instruction.
    Type: Grant
    Filed: December 10, 1997
    Date of Patent: February 8, 2000
    Assignee: NEC Corporation
    Inventor: Kazuyuki Tsunoda
  • Patent number: 5936948
    Abstract: A system and method of multiplexing a plurality of digitized data and packetized voice calls on an intersystem transmission circuit in a radio telecommunication system having a plurality of mobile switching centers (MSCs) connected by intersystem transmission circuits having a fixed bandwidth. Frame relay techniques are utilized to create a plurality of variable length frames for transporting data for the calls. A plurality of logical links are then associated with the intersystem transmission circuit, and the frames are logically connected to logical links associated with the intersystem transmission circuit.
    Type: Grant
    Filed: February 19, 1997
    Date of Patent: August 10, 1999
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventor: Alan Eric Sicher
  • Patent number: 5929772
    Abstract: A data processing device of a paging receiver having a controller for analyzing decoded paging data and for performing a paging function, wherein address data and message data of all frames are decoded and transmitted to the controller at a section of a received data stream during a scan mode of operation and, the address data and message data of a preset frame section are decoded and transmitted to the controller during a normal mode of operation.
    Type: Grant
    Filed: October 29, 1996
    Date of Patent: July 27, 1999
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Seon-Woong Hwang
  • Patent number: 5896096
    Abstract: A paging receiver having two warning modes, i.e., an audible mode and a vibrating mode, is provided. A vibrating motor of the paging receiver receives a voltage for controlling the level or intensity of vibrations provided by the motor. Various vibration voltage levels are provided to a multiplexer, and the multiplexer is controlled to sequentially output the various vibration voltages applied thereto, wherein each succeeding vibration voltage output by the multiplexer has a voltage level higher than a preceding vibration voltage.
    Type: Grant
    Filed: July 24, 1996
    Date of Patent: April 20, 1999
    Assignee: SamSung Electronics Co., Ltd.
    Inventor: Jong-Kwang Kim
  • Patent number: 5892455
    Abstract: An LCD is integrated with the cover glass of a wrist watch radio paging receiver which indicates the time data with a dial plate and hands, and a message is displayed on the cover glass by controlling this LCD. In this message display, the parts of the characters indicating the message are made transparent and the remaining parts intercept light. In this manner, message display is made possible by the difference in light transmissivity.
    Type: Grant
    Filed: July 26, 1995
    Date of Patent: April 6, 1999
    Assignee: NEC Corporation
    Inventor: Mariko Matsumoto
  • Patent number: 5889767
    Abstract: A master station and at least one slave station are connected by radio channels. Each slave station transmits data to the master station by time division multiple access. A first circuit equally divides a prescribed area into at least two sub-areas. The prescribed are is defined in a burst signal for transmitting data from each slave station to the master station, the prescribed area being provided for an arrangement of message signals which are sent from at least one terminal connected to the slave station. The first circuit also arranges a message signal in each sub-area. A second circuit generates a burst signal in which at least a control signal and a channel quality monitoring signal are arranged. The control signal and the channel quality monitoring signal are generated in the area peripheral to each sub-area in which a message signal is arranged. The prescribed area in the burst signal may be an area corresponding to a data quantity of 64 kbps in transmission speed.
    Type: Grant
    Filed: October 20, 1997
    Date of Patent: March 30, 1999
    Assignee: NEC Corporation
    Inventor: Atsushi Kimura
  • Patent number: 5883886
    Abstract: A meter reading device (22) for wirelessly transmitting meter readings from a plurality of meters (30) includes a receiver (44) for receiving a synchronization signal (60), a clock (40) connected to the receiver, a wireless transmitter (46) connected to the receiver for transmitting meter readings in synchronization with the synchronization signal, and a microcomputer (32) pre-programmable to receive meter readings from the meter and to actuate the wireless transmitter at a different specific time for each of the meters. The transmitter transmits a radio frequency signal carrying only meter readings on a reverse channel of a two-way paging system (10) during a particular reverse channel time-slot (90) of a synchronous two-way paging protocol. A messaging terminal (18) of a the two-way paging system transfers signals carrying meter readings, along with time-slot identification, to a meter reading correlator (24) which correlates the signals with each of the meters based upon the time-slot identification alone.
    Type: Grant
    Filed: January 3, 1997
    Date of Patent: March 16, 1999
    Assignee: Motorola, Inc.
    Inventors: Eric Thomas Eaton, Von Alan Mock, Philip P. Macnak
  • Patent number: 5883581
    Abstract: A method of decoding a repeat message made up of repeat message fragments at a selective call receiver (122) using a synchronous wireless protocol having time diversity includes the step of decoding (212) a repeat address N times corresponding to the repeat message. Each of the repeats of the address points to a separate repeat of an encoded vector N times wherein each of the repeats of the encoded vector explicitly points to the beginning of a first of the repeated message fragments. The method further includes the step of decoding (212) the repeated message fragments M times which was received on preassigned time slots.
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: March 16, 1999
    Assignee: Motorola, Inc.
    Inventors: Jheroen Pieter Dorenbosch, Terence Edward Sumner
  • Patent number: 5883901
    Abstract: A computer network for high-speed data communication, has a data transmission cable with a root and at least one leaf node wherein the upstream transmission is synchronized by information received on a downstream channel. Each client station receives data on a first frequency band, and transmits data on a second frequency band according to synchronization signals received on the first frequency band. The client station's transmission packets may include requests for reserved slots on the second frequency band for subsequent transmissions, and the SCS has a scheduler operable to determine a start time for requested reserved slots, and transmits the start time for the requested reserved slots. The client stations are operable to wait to continue transmission after waiting for the start time.
    Type: Grant
    Filed: November 17, 1997
    Date of Patent: March 16, 1999
    Assignee: Hewlett-Packard Company
    Inventors: Ran-Fun Chiu, Mehrban Jam
  • Patent number: 5877701
    Abstract: A radio pager of the present invention includes a non-volatile memory storing frequency information for each of a plurality of frequency bands for the confirmation of a frequency band. The frequency information are sequentially read out of the memory while frequency signals respectively corresponding to the information are sequentially fed to a frequency synthesizer, until frequency lock is detected. The frequency band to which the locked frequency belongs is determined to be the frequency band assigned to the radio pager and is reported to the operator. Therefore, even before frequency information for allowing the synthesizer to output a desired oscillation frequency corresponding to a receipt frequency is written to the pager and when a frequency band particular to the pager is not labeled on the pager body, the operator can see the frequency band easily. This prevents the operator from writing frequency information in the ROM of an inadequate radio pager to which a desired frequency band is not assigned.
    Type: Grant
    Filed: September 24, 1996
    Date of Patent: March 2, 1999
    Assignee: NEC Corporation
    Inventor: Tomio Nagakura
  • Patent number: 5870390
    Abstract: A method of receiving one of a plurality of prime rate channels transmitted via downlink signals from a satellite comprises the step of demodulating downlink signals into a baseband time division multiplex bit stream comprising frames generated by the satellite. Each of the frames comprises a plurality of time slots, each of the time slots having a set of symbols. Each symbol in the set of symbols corresponding to a respective one of the prime rate channels occupies a similer symbol position in each of the time slots. The method further comprises the steps of locating the frames in the bit stream using a master frame preamble inserted therein by the satellite, and retrieving from the set of symbols in each of the time slots of at least one of the frames the symbols that correspond to one of the prime rate channels.
    Type: Grant
    Filed: November 5, 1996
    Date of Patent: February 9, 1999
    Assignee: WorldSpace International Network, Inc.
    Inventor: S. Joseph Campanella
  • Patent number: 5867510
    Abstract: A mobile station (104) processes a paging message having information data mapped to a cyclical redundancy check (CRC) error detection code and divided into a plurality of CAC data portions mapped to a plurality of Bose-Chaudhuri-Hocquenghem (BCH) error correction codes. A BCH forward error corrector (FEC) (150) generates a plurality of BCH syndromes (538) to correct single errors that may exist in each of the plurality of CAC data portions (402), and thereby generates a plurality of post-correction CAC data portions (504). A cyclical redundancy check (CRC) error detector (152) detects if an error exists in the plurality of post-correction CAC data portions (504). An error detector (174) detects if BCH syndromes (552-562) corresponding to post-correction CAC data portions (518-528) have values of zero.
    Type: Grant
    Filed: May 30, 1997
    Date of Patent: February 2, 1999
    Assignee: Motorola, Inc.
    Inventor: Scott A. Steele
  • Patent number: 5818344
    Abstract: A selective call system including a base station having a transmitter for transmitting digital paging signals in the form of batches, each batch including a synchronization code word and concatenated message signals. While the bit rate of the message signals within each batch is the same, the synchronization code word of a particular batch contains information indicating the bit rate of the message signals in its batch.
    Type: Grant
    Filed: September 18, 1997
    Date of Patent: October 6, 1998
    Assignee: U.S. Philips Corporation
    Inventor: Anthony K. Sharpe
  • Patent number: 5812951
    Abstract: The present invention relates to a wireless personal communications system (WPCS) having several features embodied in several forms. In one embodiment, the, WPCS includes at least one RP, a first SU in communication with the RP, and a second SU in communication with the first SU through the RP without involving the RPC in the manner contemplated by the specification. The RP may preferably include a channel switching unit for connecting the first SU with the second SU without using any tariff lines to or from an RPC. Such an RP may be used as a component in a wireless PBX or Centrex system including ISDN based systems. Another preferred embodiment provides for a walkie-talkie option where the first SU communicates directly with the second SU, preferably over an unlicensed frequency. In another preferred embodiment, a plurality of SUs in communication with an RP may be accessed individually using a single dialed number.
    Type: Grant
    Filed: November 23, 1994
    Date of Patent: September 22, 1998
    Assignee: Hughes Electronics Corporation
    Inventors: Kalyan Ganesan, Ranjan Pant, Victor Liau, Robert Fischler, Kim Goh, Barry Saunders, Tayyab Khan, Harry Johnson, Desmond Coghlan
  • Patent number: 5798708
    Abstract: In a radio display paging system, a transmitted paging signal either contains an optional confidential code and a message if the message is confidential or exclusively a non-confidential message. When the paging signal is received by a destination pager, the message contained in it is stored in a message memory. If the received signal contains a confidential code, a prompt is displayed for urging a user to enter a password, and the message in memory is scrambled. If the entered password is valid, the message in memory is descrambled and displayed.
    Type: Grant
    Filed: June 12, 1996
    Date of Patent: August 25, 1998
    Assignee: NEC Corporation
    Inventor: Hideyuki Katayama
  • Patent number: 5784000
    Abstract: In a selective calling receiver receiving a first message from a transmitting side, a plurality of selective calling signals including messages and linkage orders of the messages, respectively, are sequentially received, and the messages and the linkage orders are stored into a first memory until a selective calling signal including a terminal linkage order is received. When the linkage orders stored in the first memory are numbered consecutively from a predetermined beginning linkage order to the terminal linkage order, the messages are sorted according to the linkage orders stored in the first memory to produce a second message when the linkage orders stored in the first memory are numbered consecutively. And the second message is stored as the first message received from the transmitting side into a second memory.
    Type: Grant
    Filed: August 20, 1996
    Date of Patent: July 21, 1998
    Assignee: NEC Corporation
    Inventor: Yukio Sato
  • Patent number: 5774057
    Abstract: A communications system includes apparatus for generating a succession of time message signals, a central station having a transmitter for transmitting the time message signals, at least a first receiver for receiving the time message signals and timer circuits for determining the real time of receipt of each time message signal. Each time message signal is representative of the real time of receipt, by the first receiver, of a preceding time message. The first receiver includes a clock for providing the first receiver with an internal time signal. The clock is reset upon receipt of a first time message signal and is advanced, upon receipt of a subsequent time message signal, by the real time indicated by the subsequent time message signal.
    Type: Grant
    Filed: September 1, 1995
    Date of Patent: June 30, 1998
    Assignee: Eta SA Fabriques d'Ebauches
    Inventor: Stefan Kalbermatter
  • Patent number: 5758294
    Abstract: The present invention relates to a radio port in a wireless personal communications system. The radio port includes a first channel in communication with a first subscriber unit, a second channel in communication with a second subscriber unit, and a switching device connecting the first channel to the second channel so that the first subscriber unit may communicate directly with the second subscriber unit. In another preferred embodiment, the radio port includes a plurality of antennas, an RF receive section, an RF transmit section, an analog port adapted for connection to an analog telephone line, a digital dataport for receiving and transmitting digital signals, and a databus interconnecting the RF receive section, RF transmit section, analog port, and digital dataport. The RF receive section includes a diversity selection unit receiving an input signal from each of the antennas. The RF transmit section generates an output signal to be transmitted over at least one of the antennas.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: May 26, 1998
    Assignee: Hughs Electronics Corporation
    Inventors: Kalyan Ganesan, Ranjan Pant, Victor Liau, Tayyab Khan, Desmond Coughlin, Harry Johnson
  • Patent number: 5751702
    Abstract: A networking protocol for wireless point (base station) to multipoint (user) networks where the users are stationary which utilized time-division multiplexing the in the direction of the base station to the user, heretofore called the downstream direction, and time-division multiple access in the direction of the user to the base station, heretofore called the upstream direction, where medium access control actively assigns time slots in the upstream direction to accommodate varying demands for bandwidth by multiple users, where upstream frame timing is synchronized to the downstream frame timing, where time slots carry individual ATM cells, where the first time slot of the downstream frame carries a frame start ATM cell, where upstream time slot synchronization is maintained to within .+-.
    Type: Grant
    Filed: December 5, 1995
    Date of Patent: May 12, 1998
    Assignee: Stanford Telecommunications, Inc.
    Inventors: Allan Evans, Charles Van Blaricom, April Hunter
  • Patent number: 5729827
    Abstract: A two-way paging system utilizes four local frequencies for transmissions between pager units (22) and a central control station (20). A first local frequency (f.sub.1) carries a local clock; a second local frequency (f.sub.2) carries communications packets from the central control station to paging units; a third local frequency (f.sub.3) carries communication packets from the pager units to the central control station; and a fourth local frequency (f.sub.4) carries a status or request signal from the paging units (22) to the central control station (20). Transmissions on the fourth local frequency (f.sub.4) are in accordance with a time divided slot allocation among pager units accessing the central control station (20). For a two-way paging system having a plurality of central control stations (420.sub.x) servicing a corresponding plurality of cells, a total of eight frequencies are utilized within any one cell. Four of the utilized frequencies are the local frequencies (f.sub.1 -f.sub.
    Type: Grant
    Filed: February 29, 1996
    Date of Patent: March 17, 1998
    Assignee: Digicomm, Ltd.
    Inventors: Gabriel K. Y. Wong, Po S. Tsui
  • Patent number: 5726640
    Abstract: A paging controller (10) schedules the transmission of pages of different protocol types, dynamically, taking into account both the airtime efficiency of transmitting a page of a particular protocol type and the fairness of transmitting pages of that protocol type. The paging controller (10) determines the efficiency of transmitting stored pages for each protocol type based upon the number of code words stored for the pages of the protocol type in a paging queue (27-30) and based upon the delay, if any, that is expected to be encountered in changing to the protocol type. The paging controller (10) determines the fairness of transmitting pages of a particular protocol type based upon the age of the pages of the protocol type that are stored in the paging queue (27-30).
    Type: Grant
    Filed: October 4, 1995
    Date of Patent: March 10, 1998
    Assignee: Motorola, Inc.
    Inventors: Thomas Mark Jones, W. Garland Phillips
  • Patent number: 5677681
    Abstract: If a code is transmitted at a first transmission rate, a base station modulates the entirety of the code, namely a preamble, a synchronizing signal and a call-data, by two values and transmits them at the first transmission rate. If the code is transmitted at a second transmission rate, which is double the first transmission rate, the base station modulates the preamble and the logically inverted synchronizing signal (obtained by inverting the "1", "0" logic of the original synchronizing signal) by the two values, transmits them at the first transmission rate, modulates the call-data by four values and transmits it at the second transmission rate. As a result, it suffices to provide the pager with a single common preamble detector and a single common synchronizing detector, irrespective of the transmission rate.
    Type: Grant
    Filed: May 23, 1995
    Date of Patent: October 14, 1997
    Assignee: Fujitsu Limited
    Inventors: Kenya Tanaka, Yasuhiro Yokota
  • Patent number: 5673256
    Abstract: Subscriber units (26) in a satellite communication system (10) send and receive data messages at optimum times. Each subscriber unit (26) has a pre-programmed database that includes a collection of messages (302), such as data (314), fax (316), pre-recorded voice (318), pager (320), or video files (322). Pre-programmed times include low traffic times (404) and/or most economical times (406) at the point of origination and/or destination. Low traffic time information (404) and most economical time information (406) are stored in the subscriber unit (26) and may be updated by the communication system (10). The subscriber unit (26) sends and receives messages at either a pre-programmed or low traffic time (404) or most economical time (406). The satellite communication system (10) calculates message delivery time when different from a user's time zone. A user is notified when a message is sent and received. The subscriber unit (26) stores the messages for future access.
    Type: Grant
    Filed: July 25, 1995
    Date of Patent: September 30, 1997
    Assignee: Motorola, Inc.
    Inventor: Kristine Patricia Maine
  • Patent number: 5649297
    Abstract: Two separate subcarriers are used to transmit portions of a single message to one or more receivers on an FM radio signal. The synchronization and addressing data necessary to identify the message to a target receiver is located in the first subcarrier. The second subcarrier, in turn, consists almost entirely of raw message data. Thus, transmitting multiple subcarriers substantially increases the overall data transmission payload when transmitting digital messages. Because each subcarrier is located within a different frequency band, the communication system is also adaptable to different subcarrier allotments in the FM baseband.
    Type: Grant
    Filed: October 21, 1994
    Date of Patent: July 15, 1997
    Assignee: Seiko Communications Holding N.V.
    Inventor: Daniel J. Park