Repeater trunking system

An arrangement for dedicating a communication channel between first and second radio stations through one of plural repeaters, each repeater being capable of relaying radio-frequency communications on a respectively corresponding communications channel, said arrangement comprising:

• means at the first radio station responsive to a call-originate command for locating an unused one of the communication channels;
• means at the first radio station for transmitting a busy signal to the corresponding repeater on the located unused channel;
• means at the repeater for receiving the busy signal transmitted by the first radio station and for transmitting in response thereto an acquisition signal different from the busy signal on the located channel;
• and
• means at the first radio station for receiving the acquisition signal transmitted by the repeater and generating and transmitting, in response thereto, a group signal on the located channel identifying a predetermined set of radio stations including the second radio station;
• and
• means at the second radio station for receiving, via the repeater, the group signal, thereby dedicating a communication channel between the first and second radio stations via the repeater.

In a system including a plurality of radio stations capable of communicating with one another through a repeater system operable on a plurality of channels, an improved method for establishing communication between a first radio station and a second radio station comprising the steps of:

• exchanging signals on a first channel between the first radio station and the repeater system enabling the repeater on the first channel and dedicating that first channel of the repeater system for communications between the first and second radio stations in response to successful completion of the exchanging step;
• repeating the exchanging step on a second channel in response to unsuccessful completion of the first exchanging step and continuing to attempt to exchange signals on each of the plurality of channels until a successful exchange has been completed;
• after a successful exchange of signals between the first radio station and the repeater system on one of the plurality of channels, transmitting from the first radio station a signal for identifying the second radio station;
• receiving at the second radio station the identifying signal transmitted by the first radio station and thereafter communicating between the first and second radio stations through the repeater system on the channel over which a completed exchange of signals between the first radio station and the repeater system took place.

An arrangement for dedicating a communication channel over one of a plurality of radio frequency channels between a first one of a plurality of radio stations and a second one of the plurality of radio stations through a repeater station, the arrangement comprising:

• first means for placing the second station in an idle mode and for causing the second station to scan the radio frequency channels;
• second means coupled to the first means for stopping the scanning in response to a predetermined group signal on a selected one of the channels, and enabling the second station to be operated on the selected channel in response to the predetermined group signal thereon so as to communicate with the first station on the selected channel;
• third means for placing the first station in a call originate mode and for causing the first station to scan the radio frequency channels;
• fourth means coupled to the third means for stopping the scanning on a non-busy channel in response to the absence of a busy signal on one of the plurality of radio frequency channels, and for enabling the first station to be operated on the non-busy selected channel in response to the absence of a predetermined busy signal thereon;
• and
• means, within the repeater, for receiving on an unused channel, a busy signal and transmitting on that unused channel in response thereto an acquisition signal;
• fifth means coupled to the fourth means for causing the enabled first station to transmit the busy signal on said selected channel to the repeater to operate the repeater, and for causing the first station to listen for an acquisition signal transmitted by the operated repeater on said selected channel, the successful exchange of busy and acquisition signals between the first station and the repeater being required for dedicating the selected channel for communication between the first and second stations by subsequent transmission of station selection signals from said first station through said repeater.

An arrangement for dedicating one of a plurality of two-frequency radio communication channels for communication between a first radio station and a second radio station through a repeater, said arrangement comprising:

• a repeater which repeats information transmitted thereto on a first frequency of a two-frequency radio channel and re-transmits the information on a second frequency of the two-frequency radio channel, the repeater being activated by receiving a busy signal and transmitting in response thereto an acquisition signal;
• first means for placing the first station in an idle mode and for causing the first station to scan the radio frequency channels, to stop scanning in response to a predetermined group signal detected on one of the channels, and to arrange the first station to be operated on the one channel in response to the predetermined group signal;
• and
• second means for alternatively placing the first station in a call originate mode, the second means comprising:
• means for causing the first radio station to scan the radio frequency channels;
• means for stopping the scanning in response to the absence of a busy signal on one of the plurality of channels;
• means for enabling the first radio station and the repeater on the one channel in response to the absence of a busy signal thereon;
• means for transmitting a busy signal for operating the repeater on the one channel;
• and
• means for detecting an acquisition signal transmitted by the repeater, the acquisition signal being different from the busy signal.

An arrangement for dedicating one of a plurality of radio channels communication between a first radio station and a second radio station, comprising:

• means for selectively placing the first station in either an idle mode or in a call originate mode;
• a search generator coupled to and responsive to said means for selectively placing being in the idle mode for causing the first radio station to be sequentially tuned through the plurality of radio channels and stopping the sequential tuning on a channel having at least one predetermined group signal thereon, and responsive to said means for selectively placing being in the call originate mode for causing the first radio station to be sequentially tuned through the plurality of radio channels to locate a channel having no busy signal thereon;
• and
• a sequential generator coupled to the means for selectively placing and to the search generator and responsive to the means for selectively placing being in the call originate mode for causing the first station to transmit a busy signal on the channel having no busy signal thereon, for thereafter causing the first radio station to be receptive on the channel, and for thereafter indicating in response to a received acquisition signal different from the busy signal received on said channel that the communication channel is dedicated for communication between the first and second radio stations.

An arrangement for use with a first radio station to establish communication over a radio channel selected from a plurality of radio channels through a repeater to a second radio station, the arrangement comprising:

• a search generator for causing the first radio station to become tuned to each of the channels in a repetitive sequence;
• a sequence generator for providing the sequence of first causing the search generator to tune the first radio station to locate an idle channel, second causing the first radio station to transmit a busy signal on the idle channel, third causing the first radio station to listen for an acquisition signal transmitted by a repeater in response to reception by the repeater of the busy signal transmitted on the idle channel, fourth, causing the first radio station, in response to the acquisition signal to transmit a group signal identifying the second radio station on the idle channel, and fifth stopping the transmission and causing the first station to listen for a signal on the idle channel;
• and
• means coupled to the search generator for selectively causing the first radio station to become enabled for communication on a channel having a group signal thereon specifying a group to which the first station belongs, or for selectively causing the sequence generator to enable the first radio station for communication on the idle channel in response to reception of an acquisition signal on the idle channel during the listening in the sequence generator sequence.

A method for dedicating a channel for communnication between a first radio station through a radio repeater and a second radio station over a radio channel selected from a plurality of such channels comprising the steps of:

• placing the first radio station in a call originate mode and scanning the plurality of channels until an idle channel without busy signal is located, and enabling the first station on the idle channel;
• transmitting by the first radio station a busy signal to the radio repeater to enable the radio repeater on the idle channel;
• receiving by the radio repeater the busy signal transmitted by the first radio station;
• transmitting by the repeater of an acquisition signal, different from the busy signal;
• receiving at the first radio station the acquisition signal transmitted by the radio repeater;
• transmitting by the first radio station in response to the acquisition signal at least one predetermined group signal to the radio repeater on the idle channel for retransmission by the radio repeater to enable the second radio station.

A method for establishing radio communication from a first radio station through a radio repeater to a second radio station over a radio channel selected from a plurality of such channels comprising the steps of:

• scanning by the first radio station the plurality of channels until an idle channel without busy signal is located, and enabling the first station on the idle channel;
• transmitting by the first radio station a predetermined busy signal to the radio repeater to enable the radio repeater on the idle channel;
• listening for an acquisition signal transmitted by the repeater in response to the busy signal transmitted by the first station;
• transmitting by the first radio station at least one group signal to the radio repeater on the idle channel;
• receiving by the first radio station on the idle channel to determine whether the radio repeater is transmitting the acquisition signal on the idle channel;
• and
• communicating by the first radio station with the second radio station through the radio repeater in response to the radio repeater transmitting the acquisition signal on the idle channel.

A trunking radio transceiver comprising:

• a radio receiver for receiving both control and communication signals selectively over each of a plurality of channels;
• a radio transmitter for transmitting both control and communication signals selectively over each of a plurality of channels;
• and
• a control unit, connected to control said receiver and transmitter, including means for operating the receiver and transmitter in both of the two following modes, operation occurring in either such mode, but not simultaneously:
• (a) an idle mode where at least said receiver is repetitively scanned over said plurality of channels until a predetermined control signal is detected in one non-idle channel whereupon said scanning is interrupted and subsequent communication signal transceive operations are permitted on said one channel;
• or alternatively,
• (b) a call-originate mode where at least said receiver is scanned over said plurality of channels until an idle channel is detected whereupon, (1) said scanning is interrupted, (2) a first control signal is transmitted over said detected idle channel for a first predetermined time period, (3) a second control signal different from said first control signal is received and detected over said detected idle channel during a second predetermined time period, (4) at least one of said predetermined control signals thereafter continues to be transmitted over said detected idle channel to mark it as busy, and (5) communication signal transceive operations are permitted on said detected idle channel only if steps (2) and (3) are successfully completed.

A radio repeater for use on a given channel in a plural channel trunking radio communication system, said repeater comprising:

• radio receiver means for receiving information signals on a dedicated radio receive carrier frequency;
• radio transmitter means for automatically retransmitting said received information signals on a dedicated radio transmit carrier frequency;
• and
• channel acquisition control means which (1) automatically receives and detects a first acquisition control signal on said receive frequency of the channel a second acquisition control signal, different in information content from said first control signal only if its channel comprising said dedicated receive and transmit carrier frequencies is truly in an unmarked idle status at that time and (3) which thereafter continues to cause transmission of a control signal over said transmit frequency to mark the channel as busy.