Motorola Corporation

Motorola Solutions, Inc.

John M Gilbert

Daniel J McDonald

Tanhoa Trandai

Donald R Griffis

David R Mills

Marc W Cassidy

Christopher H Wilson

Alan L Wilson

Daniel J Mcdonald

Robert A Biggs

Paul M Bocci

Harish Natarahjan

Robert J Novorita

Sanjay G Desai

Gary P Hunsberger

Larry E Feldman

Eduardo Gonzalez

A system and method for interrupting a transmitting communication unit in a communication system. When a call is first initiated, the call is assigned to a communication channel and broadcast from a base site using the assigned communication channel. If it is determined that a transmitting communication unit should be interrupted, a zone controller signals a base site to generate an interrupt message. The base site generates an interrupt message containing an identification code for the transmitting communication unit and broadcasts the interrupt message on an outbound link of the communication channel. The transmitting communication unit, while transmitting on an inbound link of the communication channel, continuously monitors the outbound link. If the transmitting communication unit receives, on the outbound link, an interrupt message containing an identification code matching its own identification code, the transmitting communication unit stops transmitting.

System and method for interrupting a transmitting communication unit in a communication system

A receiving device in the trunked radio communications system receives an outbound signaling word comprising at least an opcode field and a band plan field, wherein the opcode field indicates that the outbound signaling message is a system status message and the band plan field indicates the band plan in use on the site. In another embodiment, the receiving device receives an outbound signaling word comprising at least an opcode field, a site identification field and a four bit band plan field, wherein the opcode field indicates that the outbound signaling message is an adjacent control channel message, the site identification field identifies a second site, and the four bit band plan field indicates the band plan in use on the second site.

Method for indicating a band plan for a trunked radio communications system

A system and method for effectively and reliably terminating a voice call in any burst within a multi-burst superframe. A transmitting unit generates a termination burst upon detecting a dekey event. The termination burst includes a data synchronization pattern, a slot type field indicating an end of a call, and an information field surrounding the data synchronization pattern and the slot type field. The information field is encoded from a predetermined voice encoder frame unique to the termination burst. Once all buffered voice information is transmitted, the termination burst is transmitted prior to the end of the multi-burst superframe. A base station or other receiving unit monitors the incoming signal. Upon detecting the data synchronization pattern, the receiving unit decodes the slot type field and the information field. The receiving unit determines whether the decoded slot type field is indicative of the end of a call, and whether a specific portion of the decoded information field matches the predetermined voice encoder frame. If both are true, the receiving unit terminates the call.

System and method for terminating a voice call in any burst within a multi-burst superframe

A receiving device in a trunked radio communications system determines a transmit frequency, wherein the transmit frequency is calculated by subtracting a voice channel number from 759, multiplying by a channel spacing and adding a base frequency to yield the transmit frequency. The receiving device determines a receive frequency by a base frequency+[(759&#x2212;a voice channel number)*25,000 Hz], where the base frequency is at least one of 851.0125 MHz, 851.0250 MHz, and 851.000 MHz. In any case, the voice channel number is communicated in an outbound signaling message defined by Motorola's 3600-baud radio trunking protocol.

Method for preventing an unauthorized device from operating in a 800 MHz trunked radio communications system

A receiving device in a trunked radio communications system determines a transmit frequency, wherein the transmit frequency is calculated by subtracting a voice channel number from 559, multiplying by a channel spacing and adding a base frequency to yield the transmit frequency, if the voice channel number is between 559 and 320. The receiving device determines a receive frequency by 851.0250 MHz+[(559&#x2212;a voice channel number)*12,500 Hz], if the voice channel number is between 559 and 320. In any case, the voice channel number is communicated in an outbound signaling message defined by Motorola's 3600-baud radio trunking protocol.

Method for preventing an unauthorized device from operating in an 800 MHz trunked radio communications system using channels 559 to 320

A receiving device in a trunked radio communications system determines a transmit frequency, wherein the transmit frequency is calculated by subtracting a voice channel number from 319, multiplying by a channel spacing and adding a base frequency to yield the transmit frequency, if the voice channel number is between 319 and 0. The receiving device determines a receive frequency by 851.0125 MHz+[(319&#x2212;a voice channel number)*25,000 Hz], if the voice channel number is between 319 and 0. In any case, the voice channel number is communicated in an outbound signaling message defined by Motorola's 3600-baud radio trunking protocol.

Method for preventing an unauthorized device from operating in an 800 MHz trunked radio communications system using channels 319 to 0

A receiving device in a trunked radio communications system determines a transmit frequency, wherein the transmit frequency is calculated by subtracting 440 from a voice channel number, multiplying by a channel spacing and adding a base frequency to yield the transmit frequency, if the voice channel number is between 440 and 559. The receiving device determines a receive frequency by 851.0250 MHz+[(a voice channel number&#x2212;440)*25,000 Hz], if the voice channel number is between 440 and 559. In any case, the voice channel number is communicated in an outbound signaling message defined by Motorola's 3600-baud radio trunking protocol.

Method for operating in a 800 MHz trunked radio communications system for channels 440 to 559

Each communication unit ( A through F) and talkgroup in a communication system ( ) is assigned a priority at each site ( , and ) in the system. As communication units ( A through F) request resources, contention among requesters at a site is resolved by the priority of requesters at the site. System-wide resources are allocated equitably based on the geographical location of the communication unit using site-based priority.

Method for site-based priority in a communication system

A mobile repeater (300) is improved to include a database (303) that allows the mobile repeater to store registrations received from subscriber units. Additionally, the mobile repeater may include a voice on control switching element (309) for use with an extended control channel. Further still, the mobile repeater may include encryption elements (305-308) for the maintenance of encrypted control channels. In this manner, the mobile repeater may provide an improved quality of services to subscriber units.

Method and apparatus for a mobile repeater

A key variable correction scheme allows errored encryption key material in mobile and portables radios to be quickly identified and corrected. The errored encryption material can be corrected automatically by a key management controller, once detected. Consequently, a mismatch problem can be diagnosed and resolved in a manner which is automatic, therefore quick and efficient, and in a way which overcomes the difficulty which users have in identifying by themselves a mismatch condition since the result is often only silence out of their respective radio speaker. Once the mismatch is corrected by the reassignment of correct keys, the user is free to join the radio call already in progress.

Method for correcting subscriber-based secure call keys

A data communication protocol permits efficient and cost-effective transmission of control and ancillary messages among the components of a communication system infrastructure (200). Messages are organized into Infrastructure Control Words (300) with accompanying Format Identifiers (304), and interleaved with voice and data segments (707) to form message streams (700) that are transmitted from one infrastructure component, such as a base station (201), to another infrastructure component, such as a Digital Interface Unit (202).

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Lake Zurich, IL, United States of America

John M Gilbert