Abstract: Alternate communication services may be provided in a communication system 100 based on the geographic location of a target communication unit. When a service request, which identifies the target communication unit and a particular service, is received by a communication resource controller (101), the communication resource controller (101) ascertains the location of a target communication unit and determines whether the target unit is located within a predefined area. If the target unit (102, 103) is located within the predefined area, the communication resource controller (101) determines whether the particular service requested is prohibited in the predefined area. If the service is prohibited, an alternate service is made available to the initiating communication unit.

Abstract: A communication unit's estimated time of arrival at a target site may be determined when the location and velocity of the units has been ascertained. From this information (119), along with terrain information, an estimated time of arrival at a target site may be calculated. Having calculated the estimated time of arrival, this information is then transported to the communication units (102, 103) which is subsequently displayed to their operators.

Abstract: Processing of dispatch calls in a simulcast multisite communication system (100) begins when a source communication unit transmits a message to one or more network receivers. The received signals are analyzed immediately at the received sites for signal quality (508). Each of the signals are time stamped (510) to identify when they were received. The signal quality is then compared to the signal quality of previously transmitted highest quality signals (514). If the signal quality is of higher quality than previously transmitted highest quality signals (516), the received signals are transported with their time stamp and signal quality metric to each of the other sites via a digital communication network connecting the sites (522). Each site now performs a transmit operation by first determining the receiver source with the highest quality signal as indicated by the signal quality metric (606).

Abstract: Processing of dispatch calls in a simulcast multi-site communication system begins when a source communication unit transmits a message to one or more network receivers. The received signals are analyzed at the received sites to determine a signal quality metric. Each of the signals are time stamped to identify when they where received. The received signals are transported with their time stamp and signal quality metric to each of the other sites via a digital communication network connecting the sites. Each transmitter site performs a transmit operation by first determining the receiver source with the best quality signal as indicated by the signal quality metric. The determined best quality signal is stored until it is time to transmit the signal in phase with all the other transmitter sites in a simulcast manner. The time stamp allows a time in the future to be chosen to accommodate the worst case expected transport delay through the digital network.

Abstract: Communications may be established based on geographic location when a communication resource controller (101) transmits a communication message (119), which includes a message ID (120) a communication payload (121), and a set of geographic coordinates to a plurality of communication units (102, 103). Each of communication units (102, 103) upon receiving the communication message (119), compares its identification code (123) with the message ID (120). If a match occurs, the communication unit (102, 103) then determines its geographic location. Having obtained the geographic location, the unit determines whether its present location is within the area defined by the set of geographic coordinates and, if so, adjust its receiver to receive the communication payload (121).

Abstract: Determining transmit time of a received signal in a simulcast multi-site communication system begins when a communication unit transmits a message to one or more network receivers. The receivers transport the received signal with a time stamp to a master transceiver in the network via a digital communication network. The master transceiver then determines a launch time for transmission of a selected received signal, wherein the launch time is based on a previously executed procedure to determine the inbound and outbound delays in the simulcast multi-site communication system. Finally, the master transceiver transports the selected received signal with the launch time to other transceivers assigned to the call, wherein the transceivers transmit the selected received signal at the launch time.

Abstract: An intelligent repeater interface (101) connected to a non-intelligent repeater (102) is used to control trunked communications at a trunked communication site in a trunked communications system. The intelligent repeater interface (101) signal processes radio frequency signals received by or transmitted from a non-intelligent repeater. The intelligent repeater interface (101) also processes and stores control information. The control information and processed signals are interfaced (108, 109, and 110) directly to an external communication network (111, 112, and 113), without use of a separate central controller for the trunked communication site or system and without replacing the non-intelligent repeater with an intelligent repeater.

Abstract: Communications may be established based on geographic location when a communication resource controller (101) transmits a communication message (119), which includes a message ID (120) and a communication payload (121), to a plurality of communication units (102, 103). Each of communication units (102, 103) upon receiving the communication message (119), compares its identification code (122) with the message ID (120). If a match occurs, the communication unit (102, 103) then determines its geographic location. Having obtained the geographic location, the unit then does a table look-up to determine, based on the message ID code, a geographic communication area (126). Having obtained this information, the unit then determines whether its present location is within the geographic communication area and if so, adjust its receiver to receive the communication payload (121).

Abstract: Processing of message transmissions from any node in a simulcast multi-site communication system (100) begins when an initiating communication unit requests (400) to transmit a message to one or more network transceivers. After the request has been assigned by a call processing controller, the initiating unit transports (401) a time stamp message to each transceiver via a digital communication network (202). Each transceiver, after receiving the time stamp message, calculates (402) an outbound delay time and transports the outbound delay time to the initiating unit via the digital communication network. From the outbound delay time, the initiating unit calculates (406) a launch time, wherein the launch time accommodates the worst case expected transport delay through the digital communication network. The message to be transmitted and the launch time is transported to each of the transceivers, such that each transceiver simultaneously transmits the message at the launch time.

Abstract: An intelligent repeater (101) is used to control trunked communications at a trunked communication site in a trunked communications system. The intelligent repeator (101) transceives and signal processes radio frequency signals. The intelligent repeater (101) also processes and stores control information. The control information and processed signals are interfaced (109, 110, and 111) directly to an external communication network (117, 118, and 119), without use of a separate central controller for the trunked communication site or system.

Abstract: Determining transmit time of a received signal in a simulcast multi-site communication system begins when a communication unit transmits a message to one or more network receivers. Each receiver transports the received signal with a time stamp to each transceiver in the network via a digital communication network. Each transceiver calculates a wait period, during which, the transceiver may receive the signal and time stamp message from another receiver. Once the wait period expires, each transceiver, using a substantially similar selection method, selects the same received signal to broadcast. Each transceiver then determines a launch time for transmission of the selected received signal, wherein the launch time accommodates the worst case expected transport delay through the digital network.

Abstract: Processing of dispatch calls in a simulcast multi-site communication system begins when a source communication unit transmits a message to one or more network receivers. The received signals are analyzed immediately at the received sites for signal quality. Each of the signals are time stamped to identify when they where received. The received signals are transported with their time stamp and signal quality metric to each of the other sites via a digital communication network connecting the sites. A master transmitter site determines the receiver source with the best quality signal as indicated by the signal quality metric. The master transmitter then transports the chosen best quality signal to each of the other sites via a digital communication network. Each transmitter site performs a transmit operation by storing the chosen best quality signal until it is time to transmit the signal in phase with all the other transmitter sites in a simulcast manner.

Abstract: In a trunked communication system using intelligent repeaters (101), each intelligent repeater performs a series of tests (602, 606, 610, 614, and 618) on its own functionality. The results of these tests are transmitted (622) to a resource manager, which is one of the intelligent repeaters at a communications site. Using the results of these tests, the resource manager then selects one or more of the intelligent repeaters to perform the functions of authorization, resource allocation (708), and logging of communications (713).

Abstract: A simulcast broadcast uses digital signal processing techniques to scale pulse coded modulation samples of a signal for broadcast. Samples are adjusted to fully utilize all quantization levels representable by an 8-bit word. Time delay is adjustable using digital techniques by writing and reading data into and out of a RAM. Signal amplitude is adjustable by multiplying samples by a numeric factor. A computer can be used to adjust processing, delay and amplification of the digital signal processor.