Abstract: The disclosed invention provides a wireless communications terminal apparatus that calculates its accurate position, eliminating the influence of a repeater on the calculation without using complicated processing. The terminal apparatus receives signals transmitted from a plurality of radio stations and calculates its position, using the received signals. The terminal apparatus comprises repeater detection means for detecting a signal from a repeater which transmits signals that are generated on the basis of signals transmitted from one of the radio stations and indistinguishable from the signals transmitted from that radio station from among the received signals and position calculation means for calculating its position. When the repeater detection means has detected a signal from a repeater, the position calculation means ignores the detected signal from the repeater and calculates the terminal position, using the received signals from other radio stations.

Abstract: A delay profile estimation apparatus and a correlating unit to obtain delay profile with suppressed noise are disclosed. The delay profile estimation apparatus includes a receiving unit to receive a communication signal (received signal), a conversion unit to inverse-Fourier-transform a known pilot signal that consists of N samples, a correlating unit to obtain a correlation value between the inverse-Fourier-transformed known pilot signal and the received signal, the correlating unit being connected to the receiving unit and the conversion unit, and a delay profile generating unit for generating a delay profile of the received signal based on the correlation value. The correlating unit cyclically shifts N samples of the received signal, or the N samples of the known pilot signal when calculating the correlation value corresponding to a phase difference between the inverse-Fourier-transformed known pilot signal and the received signal.

Abstract: A digital radio stores advertisements for substitution during a broadcast for a bumpable advertisement within the broadcast. Upon detecting a bumpable advertisement within a predetermined broadcast period, the digital radio checks for higher priority stored advertisements—such as advertisements which were broadcast when the digital radio was not tuned to the station being monitored—and substitutes advertisements according to a priority scheme. Prioritization includes whether the advertisement has been played to the listener at least once during the broadcast period, and may extend to fee-based priority enhancements and tie-breakers or to selection based upon geographic location and/or direction of travel of a vehicle in which the digital radio is located.

Abstract: Frequency translation and applications of same are described herein, including RF modem and wireless local area network (WLAN) applications. Such applications include, but are not limited to, frequency down-conversion, frequency up-conversion, enhanced signal reception, unified down-conversion and filtering, and combinations and applications of same.

Abstract: A tone generator in a transceiver of a communications device may generate an arbitrary signal using two shift registers to generate the time intervals. During each time interval, a different capacitor is switched onto the node to change the voltage potential on that node. The amplitude of the waveform during each time interval is changed to provide the desired tone.

Abstract: A repeater is disclosed which is usable to permit a satellite phone, normally requiring a direct line of sight link to an orbiting satellite, to communicate with the satellite when the satellite phone is otherwise obstructed from communicating with the satellite. The repeater is usable in any situation in which the satellite phone is blocked from a direct line of site to the satellite, such as inside a building, aircraft, or natural formation (e.g., cave).

Abstract: Time alignment of a signal from a remote unit at a hub station of a multiple access system is achieved based upon an initial time indication received from the hub station at the remote unit via a satellite. The remote unit transmits a signal to the satellite, monitors for a retransmission of the signal from the satellite and measures the time difference between the outgoing and incoming signals. The remote unit, then, uses the time difference to more finely adjust the time alignment. Alternatively, the remote unit transmits a first signal advanced with respect to an on-time estimate to the hub station and receives a responsive energy indication from the hub station. The remote unit transmits a second signal delayed with respect to the on-time estimate to the hub station and receives a responsive energy indication from the hub station. The remote unit compares the two energy indications and adjusts the on-time estimate.

Abstract: An apparatus and method for delayed answering of calls directed to mobile telephones are provided. With the apparatus and method, a mobile telephone may be set to a delayed answering mode which provides a brief delay between answering of the call and actual conversation by the called party. That is, the call may be answered, but the attention of the called party is not required until the elapse of a particular delay period. This delay period allows the called party to gracefully discontinue current involvement that is requiring the attention of the called party so that the called party's attention can then be provided to the calling party. The delayed answering mode may be entered in any of a number of different ways.

Abstract: A radio signal relay for extending effective transmission distance of radio signals consists of a receiver and transmitter, a signal processing unit, an input output bus unit, a processing unit, a memory unit, a signal amplification unit and an antenna. The radio signal relay is adaptable for use in transmission modules of telephones, information peripherals, modem transmission and the like to extend the effective radio transmission distance.

Abstract: The present system comprises a transmitting apparatus for digital broadcast which includes an original signal generating section, delaying section, information amount reducing section, and transmitting section. A receiving and reproducing apparatus for digital broadcast includes a signal reception front stage unit for receiving a high quality signal and a low quality signal, mode determining section and reproducing section composed of a delaying section and selecting section for selectively reproducing the high quality signal and the low quality signal. By employing time diversity, the transmitting apparatus sends the low quality signal having a smaller bandwidth and the high quality signal so that the low quality signal has a preceding time lag relative to the high quality signal, and the receiving apparatus reproduces broadcasting programs. Utilizing the frequency band for broadcast effectively, many broadcasting programs can be increased, and the investment for providing a gap filler can be minimized.

Abstract: An RF repeater having a fixed or adjustable time delay inserted in the reverse path and/or forward path of the RF repeater is used in a first cell for improving hard handoff performance from the first cell to a second cell. Certain factors associated with the CDMA hard hand-off process effectively reduce the coverage area of the first cell, including the round-trip delay (RTD) uncertainty, the time needed to perform the hard hand-off process, and a higher forward link Eb/No requirement. Use of an RF repeater in accordance with the increases the effective coverage area of the first cell. The delayed signal from the RF repeater also allows the base station to determine the location of the subscriber station thereby identifying the particular adjacent cell to which the subscriber station will be switched (hard hand-off).

Abstract: A distributed antenna system for use in an in-building cellular telephone network, the system including a base transmission station (BTS), and a distributed antenna for conveying transmissions to and from the BTS, the distributed antenna including a plurality of serially-interconnected radiant segments, and at least one delay element intermediate two of the plurality of radiant segments, where the delay element is operative to introduce a delay in a transmission between the BTS and a mobile station (MS), where the BTS is operative to discern the delay in the transmission and thereby determine which of the plurality of radiant segments is closest to the MS and selectively radiate RF energy via the closest segment and prevent the radiation of RF energy via any other of the plurality of radiant segments.

Abstract: A method of communication and the communication system wherein, there is provided a first telephone for receiving information, time-compressing the information, storing the information and transmitting the information to a central station. There is provided at least one and generally a plurality of spaced apart central stations for receiving the time-compressed information from the first telephone, storing the time-compressed information and retransmitting the time-compressed information to a second telephone. A second telephone is provided for receiving the time-compressed information from the central station, one of storing the time-compressed information and, responsive to call-up, time-decompressing and transmitting the time-decompressed information or time-decompressing the time-compressed information and storing the time-decompressed information and then, responsive to call-up, transmitting the time-decompressed information.

Abstract: A communication network system includes a mobile node and a plurality of fixed nodes. The mobile node is a node moving along a predetermined route, and the fixed node is a node to be fixed along the predetermined route. A packet signal is sent to a destination node by way of those mobile nodes and fixed nodes. In other words, a packet communication among the fixed nodes is carried out by way of the mobile node.

Abstract: A plurality of transmitting and receiving stations are provided at randomly distributed locations within a telecommunication network, and switching circuitry is provided within the stations themselves for routing of calls between stations in the network utilizing other stations in the network for relaying of such calls where necessary. To this end each station incorporates a call routing control unit acting to select a further station to which a call from a source to a destination is to be transmitted for the purpose of relaying the call. The call routing control unit transmits an interrogation signal to be received by other stations in the network within range of the transmitting station, and the call routing control unit of each of the other stations transmits an acknowledgment signal when the station is available for relaying a call in response to the interrogation signal received from the station.

Abstract: This invention makes it possible to link separately employed pagers, PHS, and other data terminals with computer networks such as the Internet, and to schedule transfer of data to the data terminals. In a system for transferring message to pagers from user terminals connected to the Internet, a user terminal indicates to a transmission server the time for message transfer, and the transmission server, using a code conversion table, converts the message to the code adapted to the particular pager service provider and pager terminal, and transmits the message to the pager terminal at the indicated time.

Abstract: An analog transponder processor for use in a multibeam satellite receiving input beam signals and transmitting output beam signals has an input switch matrix, channel processors, and an output switch matrix. The input switch matrix power divides input beam signals into sets of input beam signals. The channel processors each receive at least one input beam signal from the input switch matrix. The channel processors filter the input beam signals into channel signals. Each of the channel signals corresponds to a respective channel of the input beam signals. The channel processors change the frequency of at least one channel signal such that the at least one channel signal corresponds to a different channel than the respective channel of the input beam signals. The output switch matrix combines the channel signals into output beam signals.

Abstract: A low-cost, low maintenance earth-based station is disclosed which includes a fixed aperture antenna directed to a fixed location. The system operates with a plurality of non-geosynchronous satellites that will periodically pass through a beam coverage region of the antenna. When one of the satellites comes within range of the earth-based station, the earth-based station detects the presence of the satellite and synchronizes the earth-based station with the satellite. When synchronization is complete, the earth-based station transmits stored data to the satellite. The data to be transmitted is stored within a data storage device that may be present at the earth-based station or remotely located and transmitted to the earth-based station using conventional techniques.

Abstract: A multicast message transmission device and a message receiving protocol device for guaranteeing a fair message delivery time for a multicast message. At the receiving protocol device, a release time of the received multicast message is set to a prescribed time specified to all receiving protocol devices of the same multicast group, and the received multicast message is stored until the release time, and then released to a corresponding upper level device. At the transmission device, each receiving protocol device is authenticated, and then the encrypted multicast messages are transmitted to the receiving protocol devices, while a prescribed decryption key corresponding to the encryption key of the encrypted multicast message is distributed the authenticated receiving protocol devices prior to transmissions of the multicast messages.

Abstract: A method for communicating location-specific messages includes storing a library of such messages within a portable device having a capability of randoly accessing the messages. Each location-specific message has a content that is related to a particular geographical location within a facility. At each of the geographical locations, there is a device-readable identification of an identifier for each location-specific message relating to that geographical location. In the preferred embodiment, the identifier is transmitted to the portable device wirelessly. Also in the preferred embodiment, the message library is contained on a recording medium that facilitates automated random access, such as a compact disk, and the portable device is a personal digital assistant (PDA). In an application of the method, map information may be prerecorded and supplemented or complemented with time-dependent information downloaded from a source.

Abstract: To carry out smooth data communication even when a radio communication channel with a satellite is in a fault state, it is judged whether the radio communication channel is in a fault state or not, and packet data transmitted from a data terminal are stored in a prebuffer and are not transmitted to the satellite when it is judged that the radio communication channel is in a fault state, and are transmitted from the prebuffer to the satellite sequentially when it is judged that the radio communication channel is recovered from the fault state.

Abstract: An arrangement of an area covering, cellular radio communication network having cell regions which can be contiguously replicated without interference. A central transceiver station is coupled to a base station controller and has a plurality of decentral transceiver stations surrounding and coupled to the central transceiver station. Groups of adjacent decentral transceiver stations are grouped in respective cell areas. All of the decentral transceiver stations in each cell area are allocated the same transmission frequencies, but the frequencies of each cell area are different from the other cell areas in the cell region.

Abstract: A satellite position/arrival-time calculating section calculates the arrival date and time at which a communication satellite is to arrive in a communicable area where the communication satellite can communicate with a satellite communication terminal apparatus, and creates communicable date and time information. A timer controls a power supply control circuit in accordance with the arrival date and time information created by the satellite position/arrival-time calculating section. The timer automatically controls the power supply control circuit so as to supply communication power to a satellite communication circuit section while the communication satellite is in the communicable area and so as to stop the supply of the communication power at the time when the communication satellite leaves the communicable area.

Abstract: A system and method for providing a re-transmitted signal substantially free of feedback is disclosed. According to a preferred embodiment of the present invention, a delay is utilized with select burst periods of a TDMA signal so as to re-transmit these burst periods coincident with a subsequent burst period of the original signal. Accordingly, the re-transmitted signal of the present invention is decoupled from the input of the original signal.

Abstract: A first portable subscriber unit (122, 602) of a plurality of portable subscriber units transmits (504) an inbound message (400) on an inbound channel. The inbound message is intended for a base receiver (616). The inbound message is received (506) by a second portable subscriber unit (606, 608) of the plurality of portable subscriber units. The second portable subscriber unit retransmits (520) the inbound message on the inbound channel only when a predetermined attribute of the inbound message satisfies (508, 510, 512, 514, 518) a predetermined condition.

Abstract: A wireless repeater comprising a first antenna for receiving a first signal from a wireless terminal and for transmitting the first signal along a first path; a second antenna for receiving a second signal from the wireless terminal and for transmitting the second signal along a second path; a summing circuit for receiving the first signal from the first path and the second signal from the second path, for summing the first signal and the second signal to form an aggregate signal, and for outputting the aggregate signal along a third path; a delay in the second signal that makes the second signal path longer than the first signal path; and a third antenna for receiving the third signal from the third path and for transmitting the third signal.

Abstract: In a mobile communication network comprising a base station (11) having a service area (13) and a plurality of mobile stations, communication is rendered possible between the base station, with a first station (15(1)) in the service area used as a repeater station, and a second station (15(2)) which may be present near or beyond a boundary of the service area. It is presumed that the mobile stations are operable with battery saving and that such a repeater station exists in a communication area (17) of the second station put into full operation. Preferably, the mobile communication network is operable with time division multiplexing, with each frame composed of a predetermined number of time slots.

Abstract: A conventional billboard for displaying a visual message is combined with a communication system for enabling a message related to the message displayed by the billboard to be transmitted from the billboard to passengers of automotive vehicles driving by said billboard. The communication system includes a transmitter located at the billboard and connected to an external telephone line. A telephone unit, disposed at a remote business office, supplies the related message over the telephone line to the transmitter. Receivers, located in individual automotive vehicles, receive the transmitted message. The transmitter includes a recorder for recording the related message received from the telephone unit and a control unit for controlling recording and playback of that message.

Abstract: An oscillation detecting apparatus for detecting an oscillation of a wireless repeater intervening between a base station and a mobile station brought in communication with each other through a TDMA system. The wireless repeater produces an input signal based on a radio wave transmitted from one of the base station and the mobile stations, and amplifies the input signal to produce an output signal. The output signal is transmitted from the wireless repeater to the other of the base station and the mobile station. The oscillation detecting apparatus comprises producing apparatus for producing a power level signal varied in proportion with an amplitude of the output signal. The power level signal is formed by, for example, an envelope of the output signal.

Abstract: The present invention provides a device (200, 300), system (400, 500) and method for real-time streaming of a multimedia file stored in a remote server over a packet network to a multimedia client connected to the same network via a low-speed access link such as an analog telephone line. The invention operates to provide significantly improved QoS with respect to both quality and delay.

Abstract: A logging recorder system for trunking radio includes a device which monitors a plurality of channels of the trunking radio system and outputs analog signals representative thereof. A digitizer is then provided for digitizing the analog signals, and a controller breaks the digitized signals into segments and stores the segments on a storage device. The controller also generates an index of locations of the segments on the storage device. The controller may then be used to selectively play back a desired conversation by automatically combining segments from the storage device based on the index.

Abstract: A radio relay communication system wherein a signal transmitted from active one of a plurality of radio units is received and recorded. When the transmission operation of the particular radio unit stops, the recorded signal is reproduced and transmitted by a relay unit, and another radio unit receives the signal from the relay unit. A relay start signal is transmitted from the first radio unit. and is received by the relay unit. In response to the relay start signal, the relay unit generates a sync signal of predetermined period. The first radio unit, in accordance with the reception of the sync signal, transmits an input signal as compressed to less than one half along the time axis. The relay unit alternates between the period of receiving the compressed signal and the period of transmission in synchronism with the sync signal.

Abstract: A two-way radio having a receiver (20) for receiving a radio signal including a voice message, a storage element (45) coupled to the receiver for storing the voice message received, a voice input device (49) for inputting voice messages, a user-actuable selection input (15) for receiving a user input to change between a transmit mode and a repeat mode and a transmitter (21) selectively coupled to the storage element and the voice input device for selectively transmitting input voice messages when in the transmit mode and retransmitting the stored voice message when in the repeat mode. A detection circuit (47) detects the radio signal and a control circuit (50) coupled to the receiver, the transmitter and the detection circuit operates in the repeat mode for activating the transmitter (21) to retransmit the voice message when the detection circuit (47) detects that the radio signal ends.

Abstract: A repeater improving the effect of a RAKE reception. A received signal from a base station parallelly passes a first path including a first delay circuit and a second path including no delay circuit, and is transmitted to a mobile station. A received signal from the mobile station parallelly passes a third path including a second delay circuit and a fourth path including no delay circuit, and is transmitted to the base station. The delay time of the delay circuits are set at one chip interval or more of a spreading code. This forcedly produces multipath waves which are resolvable by a RAKE receiver. The RAKE receiver estimates amplitudes of desired wave components for individual delayed waves, performs weighting of the respective delayed wave components from detectors by using the estimated amplitudes, and makes symbol decision in terms of the combined weighted signal.

Abstract: A logging recorder system for trunking radio includes a device which monitors a plurality of channels of the trunking radio system and outputs analog signals representative thereof. A digitizer is then provided for digitizing the analog signals, and a controller breaks the digitized signals into segments and stores the segments on a mass storage device. The controller also generates an index of locations of the segments on the mass storage device. The controller may then be used to selectively play back a desired conversation by automatically combining segments from the mass storage device based on the index.

Abstract: A system of digitally operating cordless telephone including a fixed station (20) connected with the common net (11) and several freely movable mobile stations (30.1 to 30.4). The naturally provided functional area (22) of the system can be enlarged by using a relay station (40). For this purpose the relay station (40) can permit the retransmission of transmission packages arriving from the fixed station (20) without changes to further mobile stations (30.5, 30.6) in a further functional area (23). In the other direction, the relay station (40) forwards respective packages arriving from the further mobile stations (30.5, 30.6) to the fixed station (20). For this purpose the relay station (40) maintains transmission channels, which are associated with each other in pairs and are chronologically very closely coupled, to the fixed station (20) as well as to the further mobile stations (30.5, 30.6) in accordance with the DECT Standards (Digital European Cordless Telecommunications).

Abstract: A digital satellite communication system including a local terminal coupled to a radio wireline interface through a radio satellite network. The radio wireline interface connects the radio satellite network to a public switched telephone network and a remote communication terminal. The system includes a novel method of establishing an end-to-end communication channel between local and remote terminals wherein the local terminal establishes a direct digital channel between itself and the radio wireline interface and transmits a message describing its signaling capabilities to the radio wireline interface. The radio wireline interface then trains its modem with the modem of the remote terminal such that the signaling capabilities of the local terminal are not violated. By moving the modem training procedure to the radio wireline interface, modem training response delays caused by the radio satellite network do not affect the success of establishing the end-to-end communication channel.

Abstract: An RF repeater for interfacing with a base station for exchanging transmit and receive signals in a time division duplex cordless telephone system comprises a multicarrier amplifier having an input and an output and a transfer switch connected to the amplifier output and the amplifier input and having first and second switch states. The switch means connects receive signals from the handset to the amplifier input and the amplifier output to the base station in the first switch state, and connects the base station to the amplifier input and transmit signals from the amplifier output to be broadcast to the handset in the second switch state. The operation of the switch is controlled so that the transmit and receive signals are alternately amplified by the amplifier. Thus, only a single amplifier is required.

Abstract: An information transmission system in which an information signal supplied from a base station is automatically edited at relay stations and retransmitted to terminal stations according to a retransmission schedule assigned to each relay station. The transmission schedule is transmitted together with the information signal from the base station to the relay station which in turn records portions of the information signal directed to the station itself onto a rewritable recording medium (e.g. an optical disk) and retransmits it to its terminal stations according to the retransmission schedule.

Abstract: A communication system (10) comprises a portable radio (20) and a plurality of mobile repeaters (12), a mobile repeater system 200 comprising a portable signal receiver (224) for receiving portable radio signals; a mobile transmitter (218) for transmitting the portable radio signals received by the portable receiver; a mobile receiver (226) for monitoring mobile transmissions; a delay state counter (202) for delaying the transmission of the portable radio signals received; and a received signal strength indicator (204) for determining the strength of received mobile radio signals, the received signal strength indicator being coupled to the delay state counter, via a controller (206), for decrementing the delay state counter when the mobile receiver does not detect a mobile transmission having at least a predetermined received signal strength level.

Abstract: A repeater for enhancing performance of a TDMA mobile radio system in poor signal areas has a bank of frequency agile, single channel amplifiers (13), and controller (14). The controller (14) scans the channel of the band and, upon identifying a channel carrying traffic, enables one of the amplifier units (13) to operate on that channel. Each of the amplifier units (13) includes a time slot activity detector (35) for detecting which time slot of a channel is active. The output of the activity detector (35) is passed to a logic control module (36), which controls the amplification of an active time slot via a time slot gate and power unit (38).

Abstract: A radio information system operating at low power transmits in the AM broadcast band. A message to be broadcast is digitized and stored in a random access memory. It is retrieved from the memory, converted to analog form, and used to modulate a carrier signal. The message is continuously repeated, allowing nearby persons with AM radio sets to receive the message. In order to extend the useful range of the information system, an impedance matching circuit with a high-Q inductor is located between the antenna and the output circuitry of the transmitter.

Abstract: A trunked radio system range extender extends the range of a trunked radio system by having a second repeater station monitor the control channel for the trunked radio system detect and decode control information and rebroadcast it on to a second control resource. Communications resources from the first trunked radio system are similarly mapped into a second set of communications resources for subsequent broadcast throughout an extended geographic range. The extending repeater station uses the control resource from the first repeater station.

Abstract: The invention concerns a recorded message delivery system for use in museums or tourist attractions. The system supports multiple messages for example, one message per exhibit and a user operated message player may be programmed to receive messages in one of a plurality of languages. The messages may be transmitted, for example, on different frequencies of the FM band to be received and played by the receiver/message player. Messages are played without regard for sequence at the demand of the user who may choose any message by keyboard operation of a panel of the receiver. Thus, for example, by pressing key #5 the user may hear the message relating to exhibit #5 in the language for which the receiver/player is programmed. Frequencies may be reused in different locations of the museum or attraction.

Abstract: A remotely controllable message broadcast system includes a Central Programming Station, and many Remote Message Transmitters and repeaters. The Central Programming Station includes a library of broadcast messages and a set of Remote Message Transmitter programming instructions. A transmitter in the Central Programming Station transmits selected broadcast messages from the library and selected Remote Message Transmitter programming instructions from the set to all the Remote Message Transmitters over a wide area transmission network such as a licensed radio link. The transmitted instructions may include global instructions which apply to all Remote Message Transmitters and unique (addressable) programming commands which apply to an individual one of the Remote Message Transmitters. Each Remote Message Transmitter selectively stores received broadcast messages and programming instructions based on whether it is a global instruction or a unique addressable command for that particular Remote Message Transmitter.

Abstract: A radio transmission system designed to operate on a single defined frequency channel. The system comprises a central receiver (12), at least one transmitter (14) remote from the receiver and a plurality of repeaters (13) arranged in zones (Z1 to Zn) arround the receiver. Each repeater can receive a signal from a transmitter and re-transmit the message so that it eventually reaches the receiver by way of one or more repeaters. The system includes protection means for protecting the message against loss or corruption, for example by using unique time delays before re-transmission or by addressing a certain sequence of repeaters with alternate paths being provided to guard against the message being lost.

Abstract: An automatic paging telephone set comprising first and second DTMF transmitters, a mode selector for selecting either a pager number recording mode, a paging mode, or a general communication mode, and a controller for controlling the telephone set according to the mode selected by the mode selector. When the telephone set is in the recording mode, the pager number data is stored into the memory of the controller. When the telephone set is in the paging mode, the controller stores the caller's telephone number into the memory thereof, and then transmts the pager number and the caller's telephone number to the paging system subscriber.

Abstract: An apparatus and method for selecting a number of cellular radio channels to be boosted in a given geographical area provides either F1-F1 or F1-F2 operation. The signals can be boosted at the same frequency with input to output isolation being achieved by the use of directive transmit and receive antennas physically positioned to achieve sufficient isolation. Each signal is individually filtered, amplified, and recombined for transmission. Any number of signals may be accommodated depending upon the number of retransmission channels available. Apparatus is also provided to retransmit a signal at a different frequency from that at which it is received. A tag, typically an audio tone or diminished signal amplitude gap, may be selectively applied to boosted retransmitted signals in order that they may be recognized as such.

Abstract: A simulcast broadcast system wherein two signals (103 and 106) intended for simultaneous broadcast are transmitted from a source site (100) to remote sites (200) discrete from one another. At the remote sites, the two signals are separately processed, including the introduction of appropriate delay (305 and 312), prior to combining them for broadcast in conjunction with other remote sites. One or more monitoring sites (400) can also be provided to monitor reception coherence within the system and to provide operating measurement information to allow automatic control of various simulcast system parameters, including delay.

Abstract: Data is transmitted from a mobile or a base station to a booster or repeater station which, if it identifies that the same message has been retransmitted a preset number of times by the mobile or base station it automatically retransmits the data. The number of times a message has been retransmitted may be coded on each message or determined by comparing the retransmitted messages with a previously sent message that will have been stored in memory by the repeater and when the message in memory and retransmitted message are the same, registering another transmission of the message until the preset number is registered and then retransmitting the message preferrably from memory. In another arrangement the relay station receives and stores or otherwise identifies data from the mobile or base and listens for an acknowledgement from the receiving station, if no acknowledgement is received within a preset period of time the message is automatically retransmitted by the relay station.