E.f. Johnson Company

Philip A Keefer

Keith W Barnes

Donald R Bauman

Howard N Brace

Michael E Mihelich

A method and apparatus for providing priority access for users in a transmission trunked communication system, including a plurality of distributive radio network terminal (RNT) switches and a unique signaling protocol and a switching protocol especially adapted for communication of control signals in the subaudio band for interconnecting the trunked transmission communications systems into a wide area network that provides an expanded feature set of radio communications capabilities.

Priority system for a wide area transmission trunked communication system

A land mobile transmission trunked communication system is provided with a unique switching protocol arrangement among repeaters that are networked to one or more external communication networks. The land mobile transmission trunked communication system includes a plurality of transceivers for transmitting and receiving transmission trunked radio communications over one or more radio channels. The transceivers communicate with a selected one of a plurality of repeaters to establish transmission trunked radio communications on a preassigned radio channel. The unique switching protocol arangement includes a switch that is operably connected to each repeater and selectively communicates information signals between a repeater and an external communication network. A bus system is operably connected to each repeater and to the switch for communicating control signals among all of the repeaters and the switch. The control signals include an indication for each repeater which is controlled by that repeater and by the switch as to free channel availability. Because the mechanism for controlling indications of free channel availability is operationally separate from the switch, the repeaters continue to provide transmission trunked communications to the transceivers in the event of a failure of the switch.

Method and apparatus for a distributive wide area network for a land

A method and apparatus for distributively interconnecting a plurality of land mobile trunked transmission communication systems into a wide area network includes a plurality of distributive radio network terminal (RNT) switch and a unique signaling protocol and a switching protocol especially adapted for communication of control signals in the subaudio band for interconnecting the trunked transmission communications systems into a wide area network that provides an expanded feature set of radio communications capabilities.

Method and apparatus for a remote network switch for a land mobile

A land mobile transmission trunked communication system is provided with an enhanced control signal protocol. The land mobile transmission trunked communication system includes a plurality of transceivers for transmitting and receiving transmission trunked radio communications over one or more radio channels. The transmission trunked radio communications comprises an information signal having either voice information, data information, or both, and a control signal. The transceivers communicate with a selected one of a plurality of repeaters to establish transmission trunked radio communications on one of the preassigned set of the radio channels between the repeater and one or more transceivers. The enhanced signaling protocol and switching protocol are especially adapted for communicating control signals in the subaudio band to interconnect a plurality of transmission trunked communication systems into a wide area network. The enhanced switching and signaling protocol provide an expanded feature set of radio communication capabilities.

Signaling protocol for a distributive wide area transmission trunked

A modular networking switch system for a land mobile transmission trunked communication system provides transmission trunked communications with a plurality of transceivers and networks the plurality of transceivers with remote transcievers in one or more external communication networks. The networking switch system comprises a plurality of channel interface modules (CIM), at least one telephone interface module (TIM), a system network module (SNM), a pulse code modulated (PCM) bus system, a control bus system separate from the PCM bus system, and a system management module (SMM). Each CIM interfaces with a repeater system that provides transmission trunked radio communications on preassigned radio channels between the repeater system and at least one of the plurality of transceivers. Each TIM interfaces with an external telephone communication network that provides a full duplex telephone communication between a remote transciever and the TIM. The SNM interfaces the networking switch system with other external networking switch systems that provide transmission trunked radio communications to establish a wide area network transmission trunked communication system. The PCM bus system is connected to each CIM, each TIM and the SNM for transferring voice and tone information among the modules in the networking switch system. The control bus system is separate from the PCM bus system and is connected to each CIM, each TIM and the SNM for transferring control information supplied by each CIM, each TIM and the SNM to all other modules in the networking switch system. The SMM is connected to the PCM bus system and the control bus system and selectively establishes voice and tone information paths on the PCM bus system in response to control information on the control bus system that is supplied by the other modules. As a result, the networking switch system provides for distributive control of trunking and networking interconnections within the networking switch system.

Modular networking switch system for a distributive wide area

A method and apparatus for distributively interconnecting a plurality of land mobile trunked transmission communication systems into a wide area network includes a plurality of distributive radio network terminal (RNT) switch means and a unique signaling protocol and a switching protocol especially adapted for communication of control signals in the subaudio band for interconnecting the trunked transmission communications systems into a wide area network that provides an expanded feature set of radio communications capabilities.

An alternate home channel for a land mobile transmission trunked communication system designates one of a plurality of repeaters for a given site or coverage zone as an alternate home repeater. The control signals transmitted over the subaudio band for all home channels repeaters in that site are also duplicatively transmitted over the subaudio band of the alternate home repeater. Each mobile transceiver will be programmed with two channel numbers. One for the home repeater and the other for the site alternate home repeater. When the power is turned on, the mobile transceiver determines which repeater to monitor by scanning both the home and alternate home channels. When a valid control message is detected on either channel, that channel becomes the monitor channel. Operation of the mobile transceiver is then generally similar to prior operation, with the exception that the monitor channel (either home or alternate home channel) is used instead of just the home channel.

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Waseca, MN, United States of America

Philip A Keefer