Showing papers on "Base station published in 1986"

Digital radio transmission system

Abstract: A cellular digital radio transmission system which increases the number of available communication channels between base stations and mobile stations in such system. Message transmission from a base station to its assigned mobile stations is effected by a combination of time-division, code-division and frequency-division multiplexing. Message transmission from the mobile stations assigned to a particular base station is effected by at least one of such multiplexing modes.

Digital radio transmission system with variable duration of the time slots in the time-division multiplex frame

Abstract: A cellular digital radio transmission system wherein messages are transmitted from a base station to a plurality of mobile stations assigned to it by time-division multiplexing of time slots in respective TDM time frames, each mobile station being assigned by the base station to a respective time slot constituting a channel for receiving and transmitting information. In order to fully utilize the channel capacity of the TDM time frames for users having different bandwidth requirements the base station divides each TDM time frame into time slots of different durations, whereby a mobile station can be assigned by the base station to a time slot of a duration corresponding to the bandwidth required by such mobile station.

Improvements in or relating to signal communication systems

Abstract: The invention comprises a low power broadcast system that is applicable especially to the so-called "electronic shelf" for retail stores, wherein the shelf edge carries price displaying modules that can be addressed and controlled from a central computer operated station. The system also permits the modules to broadcast back to the central station to confirm safe receipt of data and to give information as to stock levels, etc. A broadcast system avoids the need for wiring so that location changes are facilitated. To overcome the extremely noisy environment and to conserve power consumption, and hence battery life, the system employs a low frequency (132 kHz) reference carrier transmitted by the base station in discrete segmented packages, each of which frames a base data word transmitted by the base station and a corresponding module data word transmitted by the module a fixed period after the end of the base word; the base receiver then has precise time information for receipt of the module word and can "look" for it among the noise. The carrier received by the module is divided and the lower frequency used to demodulate the information-carrying transmission from the base station of the same frequency, avoiding the need for a phase locked loop detector; this lower frequency is also used for the module transmission. The module employs an air-cored loop antenna coil for the lower frequency and a ferrite-cored loop antenna for the higher reference frequency, while the store antenna is segmented for selection of the group of modules to be addressed; the antenna contacts the metal shelving to provide electromagnetic coupling thereto. Each module contains a microprocessor which controls the operation. Each module has "concealed" buttons which can be enabled and used to insert data to be transmitted therefrom. A charging circuit can be used as the power source employing the received RF carrier energy.

Signals in mobile communications: A review

Abstract: The signals in mobile communications are reviewed both in terms of the physical scenario and as the basis of the transfer function of the mobile channel. The transfer function is arranged to demonstrate the inherent limitations (the irreducible bit error rate effect) resulting from using single port antennas, in both narrow- and wide-band systems. A new model for the average source scenario at the urban-based (vehicular) mobile is determined and an analogous model for the base station is formulated. The models are useful for deriving diversity antennas.

Method of increasing the number of call options in a mobile telephone system

Abstract: A method of increasing the number of call options in a mobile telephone system with a mobile telephone exchange (MTX) and a number of base radio stations (B1-B8). The method utilizes the overlap existing between the coverage areas (A2,A5), between two base stations, one (A2) with low traffic intensity and the other (A5) with high traffic intensity. A mobile station (MB) in the area (A5) with the higher intensity is controlled such that it communicates via a channel belonging to the base station (B2) for the coverage area (A2) with the lower traffic intensity.

Integrated-services radio transmission system

Abstract: In a two-way radio transmission system, a fixed base station transmits and receives over at least one communication channel a plurality of messages for different types of receivers (TGAx) used in different services (DY). The base station transmits an organization data flow identifying the message type (TGAx) and services (DY). A plurality of different subscriber transmitter receiver sets receive each message type (TGAx) and transmits messages to the base station. The receiver sets decode the organizational data flow, and process only those messages and services which are associated with a given message and service type. In this way, different classes of communication services may be offered, using a common base station.

Burst-mode two-way radio communications system

Abstract: A burst-mode two-way radio communications system in which a plurality of antennas at a base station share a branched antenna switched dependent on the strength of the signal received from a portable transceiver, wherein a switch controller controls operation of one or more branch selection switches on the basis of an instructing signal received from any one of the base station transceivers.

Radio channel control method for mobile communication system

Abstract: A radio channel control method for a narrow-zone mobile communication system in which a plurality of base stations share a plurality of channels and each selects any of the channels for setting up a call independently of the others, e.g. a portable telephone system or a cordless telephone system. Installed in each of all the base stations are transceiver, free to use all the channels, a device capable of identifying channels on which radio waves have reached the own station based on reception sensitivity, a device for selecting a channel, a device for transmitting a pilot signal and others, and a device for setting up a call. The channel for a pilot signal is adequately changed to shorten a duration of cochannel interference. Connection of multiple base stations to a single mobile station is eliminated by causing each base station to add to the pilot signal identification data which is particular to the base station.

Adaptive splatter control

Abstract: An improved arrangement and method for use in a radio communication system is disclosed which makes possible mobile radio channel assignments on narrower channel spacings with a minimum amount of adjacent channel interference or splatter occurring at an included base station receiver. In a first embodiment, the mobile radios modify at least one transmission parameter, such as maximum allowable deviation, a given amount of transmitter output power, and a modulation limiting bandwidth, if a processed value of receive signal strength exceeds at least one predetermined threshold value. The processed value of receive signal strength is taken from a plurality of sampled and stored receive signal strength values in the mobile radio. By determining that the processed value of receive signal strength exceeds a predetermined threshold value, the mobile radio is able to adaptively control the amount of splatter caused at the base station, thus keeping the amount of splatter within acceptable levels. In a second embodiment, the improved arrangement and method incorporated in a mobile radio progressively adapts the transmission parameters upon determining that the processed value of receive signal strength exceeds a first, a second, and a third threshold value to effect reduced maximum allowable deviation only, reduce the maximum allowable deviation and power output only, or to reduce the maximum allowable deviation, power output, and modulation limiting bandwidth upon exceeding one, two, or all of these threshold values. Moreover, in each of these embodiments, the base station includes apparatus and a method for compensating the level and bandwidth of recovered audio by sensing the relative level of received signal strength in the base station receiver.

Mobile radio communications system

Abstract: A vehicle mounted mobile transceiver (11) communicates via a secondary mobile unit (51) with a short range portable unit (10). The portable unit (10) can be either a cordless microphone or a transceiver. The portable unit (10) allows a remotely positioned operator to transmit messages to a base station (13). To ensure security and reliable operation, the portable and vehicle mounted units use digitized codes for ID and instruction purposes. These codes are newly generated from time to time by the vehicle mounted unit and are imparted to the portable unit via a battery charging interface. An improved remote squelch detect is also provided. The improved remote squelch detect substitutes the normal input to the vehicle primary mounted mobile transceiver (11) squelch gate for an audio signal. The remote squelch detect can then detect the presence or absence of this input signal at the output of the audio PA for the vehicle mounted mobile transceiver, and this detection can be used to enable the secondary mobile unit to repeat the incoming message to the portable unit. With less delay than the prior art methods.

Method and apparatus for synchronizing radio transmitters in a paging network

Abstract: Method and apparatus for synchronizing radio transmitters in a paging network. A synchronization order of base stations is determined based in part upon the relative geographic locations of the stations, and is communicated to the base stations via a command signal transmitted by the paging network unit. A predetermined first base station transmits a synchronization signal to base stations to be synchronized. Subsequent sequences of synchronization signals may be transmitted from synchronized base stations until all base stations have been synchronized. The synchronization signals may be transmitted via radio waves, and the synchronization order is determined so as to minimize the number of synchronization sequences and maximize the number of base stations synchronized simultaneously in parallel. Transmitted synchronization signals are corrected to compensate for propagation delays caused by the distance between base stations and for delays which occur within an individual transceiver. Paging message signals are transmitted from a paging network unit to remote base stations for later transmission to paging receivers. Base station transmitters transmit both synchronization signals to other base stations and paging message signals to paging receivers. Synchronization signals and paging message signals may be transmitted to the base stations over different conducting media. Paging message signals are transmitted simultaneously from all base stations and are phase coherent within a common reception area so as to avoid interference. Base station transmitters are capable of transmitting both synchronization signals and paging message signals at the same frequency.

Terrestrial communications system base station

Abstract: A terrestrial radio system (100) which utilizes spot beams (41, 42, 43) time division multiple access and frequency re-use to provide communications services from a base station (10) to remote customers (11) within a system service region (12). The base station advantageously is arranged with multistage switching (515, 517, 519) so as to permit the respective sharing of radio transmitters (518) and receivers (516) over larger number of antenna transmitting and receiving ports.

Terrestrial communications system

Abstract: A terrestrial radio system which utilizes spot beams, time division multiple access and frequency reuse to provide communications services from a base station to remote customers within a system service region. The base station advantageously is arranged with multistage switching so as to permit the respective sharing of radio transmitters and receivers over larger number of antenna transmitting and receiving ports.

Synchronization method for radio transmitters in a local e.g. nationwide paging network

Abstract: The invention relates to a synchronization method for radio transmitters of a local, e.g. nationwide paging network. A paging network is connected to a public switched telephone network and comprises a paging network unit (PNU), transmitter group controllers (TGC) and transmitter site interfaces (TSI). All controllers are provided with means for receiving, processing and transmitting messages in digital form. Base stations are provided with radio transceivers (Tx, Rx) transmitting radio signals intended for paging or for synchronization of the base stations covering a common overlap area. With the method of the invention, synchronization is performed on the basis of a synchronization plan composed by paging network unit (PNU) and synchronization commands based on the plan. Synchronization proceeds sequentially in a certain order so that each base station (except for the initiator) first receives and then transmits a synchronization signal. Prior to the transmission of a synchronization signal, compensation of delays is executed based on one hand on receiving own transmission and, on the other hand, on information given by the paging network unit PNU about distances between base stations. The synchronous transmission of paging information is confirmed to be independent of a digital data transmission network by determining the exact time of radio transmission of each page according to a plan made beforehand by the paging network unit.

Connection of subscriber communication network base station to external information network

Abstract: A base station in a subscriber communication network for communicating signals between subscriber stations and an external communication network having a plurality of ports. The base station includes a communication circuit for enabling simultaneous communications between a plurality of the ports and a plurality of subscriber stations over a given communication channel having multiple sequentially repetitive time slots; a remote-connection processor for directing communications between the time slot assigned to a given subscriber station and a given external communication network port; and an exchange for connecting the communication circuit to the external communication network ports. The exchange includes a central concentrator for directing signals from predetermined external network ports to predetermined sequentially repetitive time slots in a bit stream generated by the central concentrator, and for directing signals to predetermined external network ports from predetermined sequentially repetitive time slots in a bit stream received by the central concentrator; and the remote-connection processor directs signal transfer between given sequentially repetitive time slots of the bit streams and given sequentially repetitive time slots of the communication channel. The remote-connection processor includes a remote concentrator for directing signals from predetermined remote ports to predetermined sequentially repetitive time slots in a bit stream generated by the remote concentrator and transmitted to the central concentrator, and for directing signals to predetermined remote ports from predetermined sequentially repetitive time slots in the bit stream generated by the central concentrator.

Control system of a radio telephone apparatus

Abstract: Where a carrier wave is received from a called radio telephone set and where the identification signal of the radio telephone set coincides with a preassigned identification signal, transmission of a paging signal from a base unit is stopped. Even when the identification signals do not coincide with each other, the paging signal is sent continuously over a definite interval. Communication is established only when the signal from a handset to the base station has a predetermined strength and a proper I.D.

Burst-mode two-way communications system

Abstract: A burst-mode two-way radio communications system in which transceivers (26) at a base station (20) share a common antenna arrangement having two or more branches (22, 24) and antenna branch selection is made by an operative base station transceiver having regard to the strength of the signal received from a portable transceiver with which communication is established, antenna branch selection being effected by a switch (30) controlled by a switch controller (28), such as an OR-selector, which is connected to all the base station transceivers in order to receive from any such transceiver a switching instruction signal.

Method for determining the position of mobile stations

Abstract: The invention is based on a method for determining the position of mobile stations within a cellular mobile radio network, in which a base station exchanging signals with the mobile stations is allocated to each radio cell, in which arrangement all base stations which are adjacent to the one which happens to be linked to a mobile station to be located, measure the receive quality of signal bursts which have been sent out in TDMA mode by the relevant mobile station, and then the neighbouring base stations receiving these signal bursts with adequate quality carry out signal transit time measurements, after which the mobile station is handed over to the base station for which the shortest signal transit time between it and the mobile station has been determined. For this purpose, the neighbouring base stations lock onto the signal bursts received by them and then carry out the signal transit time measurement in other frequency bands than those provided for the transmission of the said signal bursts.

Compact Large-Area Graphic Digitizer for Personal Computers

Abstract: Accurate graphic position digitizers now require the use of a tablet. In rearprojection tablets the embedded wires or electrode structure tends to limit the optical quality of the image. The ultrasonic device described here avoids these limitations. It is wireless and uses any table or surface "tablet." Two small cylindrical transducers at the base station and a third as a hand-held positioncursor are used. Specially shaped inaudible pulses sense the position of the cursor, which is wireless and battery powered, and automatically switches off when not in use. Status and positional data are communicated to the base station with an infrared beam. Resolution is 0,1 mm over an area of approximately one square meter.The base station may be integrated with the keyboard of a personal computer. The device has the operational convenience of a wireless "mouse" because it uses any convenient surface as a tablet. The x and y coordinates are calculated by triangulation, using driver software of the personal computer or a microprocessor controller. Calibration for changes in ambient temperature is made, before using the equipment, by entering the required origin and one other known position. For an alternative to the wireless cursor, the controller may also be designed to accommodate a sparking ballpoint stylus.

Mobile communication system

Abstract: PROBLEM TO BE SOLVED: To improve line quality by realizing diversity reception with an incoming line. SOLUTION: Transmission/reception shared antennas 61 , 63 ,... of a first group is arranged in closed space 7 so as to permit adjacent zones to be partially superimposed and the transmission/reception shared antennas 62 , 64 ,... of the second group are arranged in the neighborhood of the area where the zones of the first group are superimposed. The slave station devices 21 , 23 ,... and 23 , 25 ,... of the first group and the second group transmit signals inputted from the first and the second group antennas to a master station device 1. The master station device 1 synthesizes the respectively inputted signals from the first and the second group slave station devices and respectively inputs them to the first and second receiving parts 9a and 9b of a base station device 5. The base station device 5 diversity-receives the signals which are respectively inputted to the first and the second receiving parts 9a and 9b. An optical fiber is used in a transmission path between the master device 1 and the respective slave station devices 2i. When the master station device 1 is separated from the base station device 5, vertical polarized wave and horizontal polarized wave are utilized in the two incoming lines so that radio transmission is executed through the use of a polarized wave shared antenna.

A shared service algorithm for a trunked mobile system

Abstract: A model has been developed and solved which captures the essence of the concept of mobile dispatch service. There are two types of users, dispatch and interconnect (calls routed from the public switched telephone network, of much longer holding times). Also, only some of the available repeaters can be used for interconnect traffic, and blocked interconnect calls are cleared. Dispatch calls, however, can access all repeaters, and then are queued if all repeaters are busy. One design decision involves a trade between blocking of interconnect calls and queueing of dispatch calls. A formula has been derived for both interconnect blocking probability and the mean dispatch queueing time to permit this trade. The results indicate that a good operating point is to have (N - a d )(rounded down) interconnected repeaters, where there are N total repeaters and a d Erlangs of dispatch traffic.

Mobile radio system

Abstract: 1. Mobile radio system or producing telephone connections from and to vehicles (F) via radio links between vehicle-side mobile radio sets (MB) and stationary base stations (FuKo), the geographical area covered by the system being subdivided into a multiplicity of partially overlapping radio zones (Z1 to Zn) and each radio zone having a base station (FuKo) permanently assigned to it and in each case locating devices being provided in order to identify the radio zone (Z1 to Zn) corresponding to the location of the vehicle and to assign the mobile radio set (MB) to the base station corresponding to this radio zone, characterized in that in the vehicles (F) in each case a navigation unit (N) is provided which determines the location data of the vehicle by means of a vehicle-own dead-reckoning navigation system (KON), these data being corrected on passing stationary beacons with the beacon location data received thereby, and in that the mobile radio system is configured in such a way that the location data in each case determined in the navigation unit (N) are transmitted to the mobile radio set (MB) of the vehicle (F) and in that the mobile radio set (MB) evaluates these location data by comparison with the local data of the individual radio zones (Z1 to Zn) to determine the associated radio zone or the associated base station (FuKo).

Channel switching system

Abstract: PURPOSE: To eliminate call disconnection at the time of switching channels by simultaneously attain transmission and reception with a base station which is in the middle of communication at present, and the base station to be switched next at the time of switching the base stations CONSTITUTION: If channel switching starts in accordance with the shift of an interradio zone, the frequency of the new radio channel is designated with an in service control signal in the radio channel used for a call with the former base station 14 If the frequency is designated, a transmitter 12b and a receiver 13b which have not been operated until that time start with designated frequency, and a transmitter-receiver concerned in the base station 15 to be switched also starts If a continuity test with the new base station 15 completes and synchronism is established, a mobile station 11 similarly executes communication with both new and former stations 14 and 15, and the call is switched from the former channel to the new channel COPYRIGHT: (C)1988,JPO&Japio

Radio zone identification system in mobile communication

Abstract: PURPOSE: To apply highly accurate zone identification by segmenting an information signal sent from a base station into plural frames, compressing them timewise and sending an identification signal while utilizing the gap time. CONSTITUTION: An information signal 1 such as a sound signal is segmented into lots of frames 2∼6 at a prescribed period T 0 , they are subjected to time compression to form compressed frames 12∼16 having the time length of T and a signal 11 subjected to time compression is given to them. Thus, the timewise gaps 21∼24 whose length is T 0 -T are produced among the frames 12∼16, zone identification signals 230∼233 are provided sequentially at each gap and the result is sent from the base station. Thus, when the sending of the identification signal to each zone is finished, the cycle is repeated again, the mobile equipment uses a zone identification reception circuit so as to received them and when the zone is its own existing zone, the result is informed to the base station to start transmission/reception. Thus, the identification accuracy is improved, the reduction in the zone radius is attained to make the titled system suitable for the large capacity mobile communication system. COPYRIGHT: (C)1988,JPO&Japio

Ciphering key distribution system

Abstract: PURPOSE:To enhance the secrecy in the ciphering key distribution by allowing a mobile station to generate an effective ciphering key to a call at every time it takes place, informing the key to a base station with excellent reception performance and applying ciphering communication using the ciphering key. CONSTITUTION:When a call takes place in a base station, the station distributes a call occurrence notice 9 to a mobile station. The mobile station receiving the call occurrence notice 9 distributes a ciphering key in a reply notice 11. The base station receiving the reply notice 11 informs the channel assignment notice 12 to the mobile station and uses the ciphering key in reply notice to make talking 13. When a call takes place in the mobile station, a ciphering key is given in a call occurrence notice 15 and sends it to the base station, where the notice 12 is sent to the mobile station. The talking 13 is applied by using a set ciphering key. Since the reception performance of the base station is far better then the reception performance of the mobile station, the ciphering key is not leaked to other mobile stations.

Radio paging system

Abstract: PURPOSE:To allow a caller to recognize the state of a called party by transmitting a reply signal comprised of codes when a pager possessor confirms a call, decoding the reply signal at a base station and informing the signal to the caller. CONSTITUTION:A signal received in a pager via an antenna 1 and an antenna switch 2 is demodulated by a reception RF circuit 11, a demodulation signal is led to a decoder 12, and when it is discriminated that the call is addressed to the own pager, a beeper 13 is energized to inform the call to the possessor. When the pager possessor confirms the call to the own pager, an operation circuit 23 is operated to activate a power supply control circuit 3 to apply power to a transmission RF circuit 21 and an encoder 22. The encoder 22 encodes the content of operation inputted to the circuit 23 to generate a code in response to the content of operation. The code is led to the circuit 21 to modulate the carrier, the result is amplified and irradiated from the antenna 1 via the switch 2. The radio wave is received by the base station, where the signal is decoded and informed to the caller as the status of the called party.

Polling control system

Abstract: PURPOSE:To attain the talking between a mobile station and a base station by allowing the mobile station to send a communication request signal to a base station even during the polling reply period and allowing the base station receiving the said talking request signal to stop the return of the reply signal from each mobile station. CONSTITUTION:The talking by a microphone 209 of a mobile station 20 is inhibited by a control central processing means 204 normally during the reply period of each mobile station 20 based on the polling of the base station 10 and in depressing a press switch SW of the microphone 209 of a mobile station, e.g., 20-1, a talking request signal Q from the control central processing means 204 is sent via a modulation/demodulation means 203, a radio equipment 202 and an antenna 201. The talking request signal Q is received by the radio equipment 105 via an antenna 106 of the base station 10 and demodulated into a digital signal by the modulation/demodulation means 103 via a remote control device 104. When the control central processing means 204 identifies the talking request signal Q, a reply stop signal S is returned.

Phase adjusting system in mobile communication system

Abstract: PURPOSE: To easily attain phase adjustment even if a phase of any transmission signal is deviated largely by designing the system that a time slot assigned to an adjusting station and a time slot assigned to a reference station are not adjacent to each other. CONSTITUTION: In two adjacent radio base stations, the time slot assigned to one radio base station functioning as an adjusting station and the time slot assigned to the other radio base station functioning as the reference station are not adjacent to each other. In cast of adjusting the phase by a radio base station RZ3 while using a radio base station RZ2 as a reference station, the time base of a control channel sent by the radio base station RZ3 is deviated largely and the time position of the time slot is overlapped with the adjacent time slot, but the transmission information of the reference station is not destroyed. In the adjacent time slot to be overlapped, the transmission is finished or a weak electric field takes place, then the radio base station RZ3 receives its own transmission information without destruction. COPYRIGHT: (C)1988,JPO&Japio

Line check device of automobile telephone base station

Abstract: PURPOSE:To attain normal talking between a base station and other location and to conduct the line test by providing a line switch having a signal loopback function and a wired line connector having a signal loopback function of a wired line of the base station to a mobile set. CONSTITUTION:In conducting the line check, when a test signal from a control section 21 of an automobile telephone exchange station is transmitted, the test signal enters a transmitter 4 through a private line 3 and a wired line connector 14. The test signal is transmitted from the transmitter 4 in a transmission frequency fT, received by a radio equipment main body 17 of a mobile set through a directional coupler 15 and a duplexer 16, the signal goes to a voice band frequency signal, which enters a line switch 18. In checking private lines 3, 8 the connector 14 is activated by using a loopback control signal from a base station control section 26 receiving the control section 21 to apply the check of the control section 21 and lines 3, 8.

Wireless zone deciding system

Abstract: PURPOSE:To enable a mobile station to select a base station by simple constitution by making the base station that received radio wave from the mobile station send out a replay signal at timing having fixed relation with the receiving level, and making the mobile station accept the first answer signal. CONSTITUTION:When a mobile station 9 sends out a transmission signal S that selects base stations 81-83, and waiting for a answer signal R, a base station that received 10 the signal S measures receiving level in a level measuring section 11. A control section 12 stores the value of receiving level measured by a processor 14 in the measuring section 11 in a register 15, and compares the value with a reference level stored in a memory 17, determines delay time ti until transmission of a signal R, sets corresponding time to a timer 16 and sends out the signal R from a transmitting section 13 when time out. The mobile station 9 receives the signal R sent out first, and reads out base station discriminating information to determine the base station, and at the same time, sends out a signal toprohibit sending of the signal R. Selected base station connects the received information to an exchange 7.