Motorola Corporation

Motorola Solutions, Inc.

Tanhoa Trandai

Daniel J McDonald

John M Gilbert

Marc W Cassidy

Donald R Griffis

Christopher H Wilson

David R Mills

Andor Almasi

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 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

A receiving device in a trunked radio communications system retrieves a first frequency from a scan list and tunes to about the first frequency. If no control channel messages are decoded at the first frequency, then the receiving device tunes to about a second frequency. If no control channel messages are decoded at the second frequency, then the receiving device iterates through the scan list, until the last frequency in the scan list is reached, wherein the scan list comprises control channels for at least two band plans.

Method for determining a control channel in a trunked radio communications system utilizing a scan list

A receiving device in a trunked radio communications system determines transmit and receive frequencies by a mapping. The receiving device receives a voice channel number, wherein the voice channel number is communicated in an outbound signaling message defined by Motorola's 3600-baud radio trunking protocol. The receiving device tunes to about a transmit frequency of 806.0250 MHz, if the voice channel number is 440; tunes to about a transmit frequency of 806.0500 MHz, if the voice channel number is 441; tunes to about a transmit frequency of 806.0750 MHz, if the voice channel number is 442; etc. The receiving devices tunes to about a receive frequency of 852.5250 MHz, if the voice channel number is 500; tunes to about a receive frequency of 852.5500 MHz, if the voice channel number is 501; tunes to about a receive frequency of 852.5750 MHz, if the voice channel number is 502; etc.

Method for operating in an 800 MHz trunked radio communications system by mapping channels to frequencies

A receiving device in a trunked radio communications system retrieves a first frequency, wherein the first frequency relates to a lowest frequency that the at least one repeater utilizes for transmission and tunes to about the first frequency. If no control channel messages are decoded at the first frequency, then the receiving device tunes to about a second frequency wherein the second frequency is a channel separation of 12.5 kHz from the first frequency. If no control channel messages are decoded at the second frequency, then the receiving device, iteratively increments the second frequency by the channel separation until the second frequency reaches an end of band frequency for the trunked radio communications system.

Method for determining a control channel in a trunked radio communications system

A receiving device in a trunked radio communications system requests a voice channel for a communication and receives an outbound signaling message on a control channel comprising a voice channel number for the receiving device to utilize for the communication. The receiving device tunes to about a transmit frequency, wherein the transmit frequency is determined by multiplying the voice channel number by a channel spacing and adding a base frequency to yield the transmit frequency, if the voice channel number is between 0 and 119. The receiving device modulates the communication to about the transmit frequency and transmits the modulated communication with a transmit deviation that relates to a maximum of 4 kHz.

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Arlington Heights, IL, United States of America

Tanhoa Trandai