Abstract: A dispatcher console for use in a digitally trunked, multisite public service radio system. The dispatcher counsel comprises a personal computer having a co-processor logic board, an audio switching tower, and user I/Os including a customized keyboard, display screen, audio speakers, headset and a transmit foot pedal. The switching tower routes audio communications between the console and multisite switch. The tower is controlled by and connected directly to the co-processor board. The customized keyboard is also connected directly to the co-processor board and has dedicated keys for commonly performed functions. The display screen presents information in a standard format such that the dispatcher knows precisely where to find particular information.

Abstract: A multisite network switch for a series of RF digital trunked radio transceivers and dispatcher consoles. The switch establishes audio communications between different sites and various dispatcher consoles. The multisite switch has a distributed architecture in which each node of the switch is supported by a microprocessor controlled card. These nodes perform all of the logical functions of the switch. When the switch is booted-up or reset, each node executes a dynamic address generation algorithm to select a unique address and resolve any address conflicts with other nodes.

Abstract: Digitally trunked radio transceivers are permitted to roam over an extended coverage area including two or more digitally trunked radio frequency communication networks. Each network includes at least one digital repeater site having a corresponding site coverage area and serving digitally trunked radio transceivers disposed within or near the site coverage area. Each network also includes a local multisite switch for routing communications between the digital repeater sites within the networks. Site adjacency information is established for each site and communicated between the networks. Each digitally trunked transceiver maintains a site adjacency list for its currently selected site and modifies that list when the transceiver roams into a new site coverage area and selects a new repeater site.

Abstract: A multisite network switch for a series of RF digital trunked radio transceivers and dispatcher consoles. Each transceiver covers a certain site area. The switch establishes audio communications between different sites and various dispatcher consoles. The multisite switch has a distributed architecture in which each node of the switch is supported by a microprocessor controlled card. Each node interfaces with a site, dispatcher console, system manager or other system component.

Abstract: A distributed switching network (switch) routes audio and control signals throughout the switch from various audio sources to one or more audio destinations. Audio sources such as mobile/portable radio units (via RF repeater transmitters), dispatch consoles, and landline telephone subscribers (via the central telephone switching network) are preassigned and routed onto an audio channel (i.e. a time slot) on a time division multiplexed (TDM) audio bus through a corresponding interface module. These interface modules broadcast digitized audio and data signals to all other interface modules over their preassigned TDM bus slot. Audio routing is performed to the audio destinations through corresponding interface modules that selectively "listen" to active TDM network channels. A digital voice interface module is provided in the switch to permit audio sources/destinations otherwise lacking certain digital processing capabilities (e.g. encryption/decryption) to participate in such digitally based calls.

Abstract: A multisite network switch for a series of RF digital trunked radio transceivers and dispatcher consoles. Each transceiver covers a certain site area. The switch establishes audio communications between different sites and various dispatcher consoles. The multisite switch has a distributed architecture in which each node of the switch is supported by a microprocessor controlled card. The nodes are connected by audio buses and a dedicated message bus. The messages on the message bus allow the nodes to communicate control information regarding the status of slots on the audio bus, the members in groups, the location of radio units, call types and a host of other information needed to operate the switch.

Abstract: A multisite network switch for a series of RF digital trunked radio transceivers and dispatcher consoles. The switch establishes audio communications between different sites and various dispatcher consoles. The multisite switch has a distributed architecture in which each node of the switch is supported by a microprocessor controlled card. These nodes perform all of the logical functions of the switch. When the switch is booted-up or reset, each node executes a dynamic address generation algorithm to select a unique address and resolve any address conflicts with other nodes.

Abstract: A multisite network switch for a series of RF digital trunked radio transceivers and dispatcher consoles. The switch establishes audio communications between different sites and various dispatcher consoles. The multisite switch has a distributed architecture in which each node of the switch is supported by a microprocessor controlled card. This card has a communications controller that routes messages between the internal switch bus, an outside port and an interface processor that controls the audio slots in the switch. The communications controller receives control messages from the switch bus, but discards redundant slot status messages by checking a slot status bit map stored in a memory unit on the card.

Abstract: An interface for a conventional base station into a digitally trunked network of RF communications systems acts a pseudo-down link from a multisite switch to a trunked site controller. The interface monitors the conventional channels from the base station and sends a channel assignment message to the multisite switch when it detects a voice signal. The channel assignment message notifies the trunked RF systems that a new call is active so that each system can assign a trunked working channel to the conventional call. Similarly, the multisite switch sends a channel request when a trunked call is to be broadcast over a conventional channel. The interface keys the channel and couples the channel to the trunked call.

Abstract: A radio frequency (RF) signal transmission system is interconnected by a multisite switch that routes command and audio transmission signals between the RF systems. The multisite switch has a distributed architecture of nodes wherein each node is coupled to one of the RF systems, such as a site controller or dispatcher console. Each of the switch nodes has a common architecture in which a single controller board operates a plurality of audio boards. In addition, the controller board has two principal processors that communicate with each other via a dual-port RAM.

Abstract: A communication link for a dispatcher console to a multisite network of RF digitally trunked radio site transceivers and other dispatcher consoles. The communication link provides the dispatcher console direct access to a wide area RF network. A multisite central switch establishes audio and control communications between the different sites and various dispatcher consoles. The dispatcher consoles have audio and control links to the multisite switch. The multisite switch has a distributed architecture in which a switch node interfaces with the dispatcher console. A control communication protocol provides a standard format for message packets between the multisite switch and dispatcher console.