Reflex Type Patents (Class 455/342)
  • Patent number: 5263175
    Abstract: A diversity repeater that incorporates diversity diagnostic circuitry. The diversity diagnostic circuitry monitors the outputs of at least two receivers and determines the signal strength of the transmissions received by each receiver. If the signal strength for a particular receiver is below a predetermined threshold, the diversity diagnostic circuitry determines whether that receiver is receiving a rayleigh faded transmission or is an inoperative mode.
    Type: Grant
    Filed: September 28, 1990
    Date of Patent: November 16, 1993
    Assignee: Motorola, Inc.
    Inventor: James W. Dejmek
  • Patent number: 5263176
    Abstract: In a multi-station radio communications system wherein plural channels are accessible for communication between plural fixed stations and plural mobile units (viz., dynamic channel assignment) and wherein each of plural fixed stations selects a channel according to channel assignment priority data, the radio channels are grouped into a plurality of channel groups. The channels in each of the channel groups forms a numerically looped sequence of channels. The first channel of the numerically loop sequence in one channel group is different from the first channel of the numerically looped sequence in each of the other channel groups. Each of the plural fixed stations is set to select the channel having the highest priority or to select one of the first channel of the numerically looped sequence and a channel nearest to the first channel in the event that a plurality of channels have the same priority.
    Type: Grant
    Filed: February 8, 1991
    Date of Patent: November 16, 1993
    Assignees: NEC Corporation, Nippon Telegraph and Telephone Corp.
    Inventors: Susumu Kojima, Tetsuro Hanazawa
  • Patent number: 5239670
    Abstract: A satellite based paging communication system comprises a plurality of terrestrial stations capable of communicating the paging information with at least one satellite. The satellite(s), in turn, are capable of communicating the paging information to at least one terrestrial receiver or terrestrial station. Also included is at least one control station for determining where and how to deliver the paging information to one or more of a plurality of terrestrial receivers (pagers), at least some of which are capable of receiving the paging information from one or more of the satellites and one or more of the terrestrial stations.
    Type: Grant
    Filed: November 30, 1989
    Date of Patent: August 24, 1993
    Assignee: Motorola, Inc.
    Inventors: Robert J. Schwendeman, William J. Kuznicki
  • Patent number: 5239667
    Abstract: When communication is established using a mobile radio terminal, the speed at which the terminal is moving is measured by monitoring the Rayleigh fading of the signal strength. Using this velocity indicative parameter, a threshold level which is used to determine if a handoff is required or not, can be adjusted in a manner which renders the decision process more accurate and minimizes the number of unwarranted handoffs.
    Type: Grant
    Filed: January 31, 1991
    Date of Patent: August 24, 1993
    Assignee: NEC Corporation
    Inventor: Toshihito Kanai
  • Patent number: 5235329
    Abstract: A combination to detect the proximity of an emergency vehicle including a transmitter in the emergency vehicle and a receiver in another vehicle, the receiver actuating an alarm such as a blinking light upon the reception of a transmission from an emergency vehicle.
    Type: Grant
    Filed: October 1, 1991
    Date of Patent: August 10, 1993
    Assignee: E A S Emergency Alert Systems, Inc.
    Inventor: LeGrant Jackson
  • Patent number: 5214790
    Abstract: An enhanced talkgroup scanning algorithm is provided. This algorithm provides an efficient scan function when a unit scan list contains a mixture of trunked talkgroups and conventional channels. This is accomplished by adding a new scanning algorithm for conventional priority groups, and by enhancing the trunking talk group scanning cycle. A novel scanning algorithm for conventional priority groups is used to decrease the audio holes in trunking calls when looking back at a priority conventional channel. When a unit is active on a low priority trunking call and goes over to the priority conventional channel to check for activity, several new steps are taken into consideration when the unit goes back to the trunked system/active trunked call. Based on whether there has been activity on the priority channel, the unit will immediately return to the old voice channel (unsquelched) or revert to the control channel.
    Type: Grant
    Filed: March 11, 1991
    Date of Patent: May 25, 1993
    Assignee: Motorola, Inc.
    Inventors: Thaddeus A. Kozlowski, Daniel J. McDonald, Guy G. Romano
  • Patent number: 5214788
    Abstract: The process consists in:using at least one transceiver station to search for a set of usable frequencies,transmitting the set of usable frequencies to the other transceivers in the networkand performing the communication transfers in frequency hopping in the set of usable frequencies communicated to all the transceivers in the network.
    Type: Grant
    Filed: May 4, 1990
    Date of Patent: May 25, 1993
    Assignee: Thomson - CSF
    Inventors: Jean-Paul Delaperriere, Alain Eberland, Yves Singlas
  • Patent number: 5212803
    Abstract: A method in a mobile radio station to select one of a number of dedicated control channels (DCCH1-21) which are transmitted from a number of base stations (B1-B21) in a mobile radio system. In the mobile station there is an equalizer to compensate for the multipath propagation characteristics of the radio medium between the mobile station and a certain base station. This equalizer is power consuming and should not be used if not necessary. According to the method an investigation is carried out in the mobile station whether or not the equalizer can be disconnected during the initialization of a call from the mobile to a base station. The signal quality of the dedicated channel (DCCH1) which has the greatest signal strength is measured without the equalizer. If the signal quality is not acceptable, a new detection is made with the use of the equalizer.
    Type: Grant
    Filed: September 6, 1990
    Date of Patent: May 18, 1993
    Assignee: Telefonaktiebolaget L M Ericsson
    Inventors: Jan E. Uddenfeldt, Alex K. Raith
  • Patent number: 5203013
    Abstract: A radio telephone communication system (200) comprising a base station with at least one frequency agile transceiver (207) capable of time division duplex operation on at least one radio frequency channel. The base station operates to facilitate communication with at least one radio telephone (100) on the at least one radio frequency channel.
    Type: Grant
    Filed: September 10, 1990
    Date of Patent: April 13, 1993
    Assignee: Motorola, Inc.
    Inventors: Robert L. Breeden, Gary S. Lobel, Thomas V. D'Amico
  • Patent number: 5203011
    Abstract: A communication system (100) is provided comprising a communication resource controller (110) wherein the likelihood of success for establishing synchronous digital communication with a communication unit (120) is substantially greater than the likelihood of success for establishing analog communication. The communication unit may establish analog communication after the communication resource controller receives a digital access code from the communication unit. The analog communication is deferred until the received signal strength from the communication resource controller is above a predetermined level which makes the establishment of analog communication substantially likely.
    Type: Grant
    Filed: September 4, 1990
    Date of Patent: April 13, 1993
    Assignee: Motorola, Inc.
    Inventors: Ronald L. Bane, Tanh Q. Van
  • Patent number: 5193209
    Abstract: On-board equipment for a mobile telephone system has a function of reporting the degree of busyness of message channels available in a service area. While the equipment is in a stand-by condition with no communication being held thereon, the degree of busyness is determined on the basis of electric field levels of individual message channels or control information sent from a control station. When the electric field levels are used to determine the degree of busyness, the electric fields of a plurality of message channels assigned to the service area are detected. If any of the message channels has an electric field level higher than a predetermined level, that message channel is determined to be busy. The rate of use of the message channels is calculated by using the number of assigned message channels and the number of occupied message channels. The calculated rate of use is displayed as information which is indicative of the busyness of the message channels.
    Type: Grant
    Filed: April 27, 1990
    Date of Patent: March 9, 1993
    Assignee: NEC Corporation
    Inventors: Koji Maeda, Shinji Kawamura
  • Patent number: 5125101
    Abstract: A moble radio system is disclosed in which communication is established between at least two user-operable stations over one of a plurality of channels by operating the user-operable stations in accordance with the following steps:(1) When in the receive mode (the push-to-talk switch is open):(i) incrementing the channel selector to select a channel;(ii) determining if a carrier signal is present on the selected channel:(iii) if a carrier signal is not present, returning to step (1) (i);(iv) if a carrier signal is present, determining if the selected trunk identification signal is present on the carrier signal;(v) if the selected trunk identification signal is not present, returning to step (1) (i); and(vi) if the selected trunk identification signal is present on the carrier signal, enabling said transmitter for push-to-talk operation.
    Type: Grant
    Filed: February 16, 1990
    Date of Patent: June 23, 1992
    Assignee: Etrunk Systems, Inc.
    Inventors: Edward K. Johnson, Fred E. Stuebner
  • Patent number: 5119502
    Abstract: A method for use in a cellular radio telephone system for controlling, in at least one mobile station, rescanning operations of paging channels in the system, wherein the mobile station is operationally connected to at least one base station. The method involves broadcasting a rescan message from the base station to the mobile station at predetermined intervals during operation of the base station. Pages to be sent to the mobile stations are stored immediately following broadcast of the rescan message until such time as all mobile stations have had an adequate opportunity to carry out the rescanning operation.
    Type: Grant
    Filed: August 30, 1990
    Date of Patent: June 2, 1992
    Assignee: Telefonaktiebolaget L M Ericsson
    Inventors: Harald Kallin, Roland S. Bodin