Repeater for a controlled radio system

Claim 2

A fixed repeater for facilitating communication between a subscriber unit and a central station when said subscriber unit is located in a zone of weak signal strength wherein direct communication between said central station and said subscriber unit cannot occur, comprising: receiver means for receiving signals transmitted by said subscriber unit and said central station; transmitter means for transmitting signals to said subscriber unit and said central station; and control means, responsive to received signals, for recognizing a transmission representing at least a call request from said subscriber unit to said central station, and an absence of a channel grant from said central station in response to said transmission representing at least said call request from said subscriber unit, wherein said fixed repeater repeats transmissions between said subscriber unit and said central station by utilizing said receiver means and said transmitter means for transmitting signals to said subscriber unit and said central station.

Claim 3

A fixed repeater for facilitating communication between a central station and a subscriber unit, said subscriber unit having transmitting means to request service of said repeater, comprising: monitoring means in said fixed repeater for receiving signals from said subscriber unit on a first channel; receiver means for receiving a signal requesting said repeater to repeat transmissions between said subscriber unit and said central station transmitted by said subscriber unit on said first channel; and control means responsive to said signal request of repeater service to relay transmissions between said subscriber unit and said central station by switching to an assigned channel already designated for said fixed repeater.

Claim 4

A fixed repeater for facilitating communication between a central station and a subscriber unit, said subscriber unit having transmitting means to request service of said repeater, comprising: monitoring means in said fixed repeater for receiving signals from said subscriber unit on a first channel; receiver means for receiving a signal requesting said repeater to repeat transmissions between said subscriber unit and said central station transmitted by said subscriber unit on said first channel; and control means responsive to said signal request of repeater service to relay transmissions between said subscriber unit and said central station by switching to an assigned channel already designated for said fixed repeater.

Claim 15

In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units and each subscriber unit having at least an individual identification code, said subscribers constructed and arranged to communicate information on any of the communication channels, a method for a repeater having at least an individual identification code to initiate communication between any of the plurality of subscribers and said at least one central controller comprising the steps of: (a) receiving in said repeater a first message from said subscriber unit comprising at least a call request information word representing said subscriber unit's identification code; (b) receiving in said repeater a second message from said central controller representing said subscriber unit's identification code and a channel assignment; (c) determining whether said second message from said central controller has been received before receiving a predetermined number of said first messages from said subscriber comprising at least said call request; (d) transmitting a third message to said central controller representing said subscriber's individual identification code and said repeater's identification code, in response to receiving a predetermined number of said first messages from said subscriber unit before receiving said second message from said central controller; and (e) receiving in said repeater a fourth message from said central controller comprising at least channel grant information words each representing a channel assignment for said subscriber to communicate with said repeater, and a channel assignment for said repeater to communicate with said central controller and other subscriber units.

Claim 16

In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units and each subscriber unit having at least an individual identification code, said subscribers constructed and arranged to communicate information on any of the communication channels, a method for a repeater having at least an individual identification code to initiate communication between any of the plurality of subscribers and said at least one central controller comprising the steps of: (a) receiving in said repeater a first message from said subscriber unit comprising at least a call request information word representing said subscriber unit's identification code; (b) receiving in said repeater a second message from said central controller representing said subscriber unit's identification code and a channel assignment; (c) determining whether said second message from said central controller has been received before receiving a predetermined number of said first messages from said subscriber comprising at least said call request; (d) transmitting a third message to said central controller representing said subscriber's individual identification code and said repeater's identification code, in response to receiving a predetermined number of said first messages from said subscriber unit before receiving said second message from said central controller; and (e) receiving in said repeater a fourth message from said central controller comprising at least channel grant information words each representing a channel assignment for said subscriber to communicate with said repeater, and a channel assignment for said repeater to communicate with said central controller and other subscriber units.

Claim 17

In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units and each subscriber unit having at least an individual identification code, said subscriber unit constructed and arranged to communicate information on any of the communication channels, said communication channels includes a plurality of designated channels, a method for a repeater having at least an individual identification code to provide communication between any of the plurality of subscriber units requesting access to said repeater and said at least one central controller comprising the steps of: at said subscriber unit: (a) transmitting a message to said repeater comprising at least a call request information word being organized in fields, wherein a first field represents said subscriber's individual identification code, and a second field represents a status code when a signal ceases to be received from said central station; (b) scanning through said plurality of designated channels for reception of a signal representing a handshake on one of said plurality of designated channels; (c) transmitting a signal representing an acknowledgement when said handshake has been received on one of said plurality of designated channels; at said repeater: (a) receiving said message from said subscriber unit comprising at least a call request information word representing said subscriber's individual identification code and said status code; (b) transmitting a message to said central controller comprising at least a call request information word representing said subscriber's individual identification code and said repeater's identification code; (c) receiving a message from said central controller comprising at least channel grant information words each representing a channel assignment for said subscriber to communicate with said repeater, and a channel assignment for said repeater to communicate with said central controller and other subscriber units; (d) transmitting said signal representing said handshake to said subscriber unit on said one of said plurality of designated channels; (e) receiving said signal representing said acknowledgement from said subscriber unit on said one of said plurality of designated channels.

Claim 18

In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units and each subscriber unit having at least an individual identification code, said subscriber unit constructed and arranged to communicate information on any of the communication channels, said communication channels includes a plurality of designated channels, a method for a repeater having at least an individual identification code to provide communication between any of the plurality of subscriber units requesting access to said repeater and said at least one central controller comprising the steps of: at said subscriber unit: (a) transmitting a message to said repeater comprising at least a call request information word being organized in fields, wherein a first field represents said subscriber's individual identification code, and a second field represents a status code when a signal ceases to be received from said central station; (b) scanning through said plurality of designated channels for reception of a signal representing a handshake on one of said plurality of designated channels; (c) transmitting a signal representing an acknowledgement when said handshake has been received on one of said plurality of designated channels; at said repeater: (a) receiving said message from said subscriber unit comprising at least a call request information word representing said subscriber's individual identification code and said status code; (b) transmitting a message to said central controller comprising at least a call request information word representing said subscriber's individual identification code and said repeater's identification code; (c) receiving a message from said central controller comprising at least channel grant information words each representing a channel assignment for said subscriber to communicate with said repeater, and a channel assignment for said repeater to communicate with said central controller and other subscriber units; (d) transmitting said signal representing said handshake to said subscriber unit on said one of said plurality of designated channels; (e) receiving said signal representing said acknowledgement from said subscriber unit on said one of said plurality of designated channels.