Audio routing within trunked radio frequency multisite switch
First Claim
1. In a digitally trunked radio frequency communications system, a distributed audio routing arrangement for routing audio signals between an audio source and any of plural audio destinations, said distributed audio routing arrangement comprising:
- a time-division multiplexed digitized audio signal bus defining at least one time slot dedicated for use by said audio source;
said audio source being coupled to said audio signal bus, said audio source applying digitized audio signals to said audio bus dedicated time slot to thereby broadcast audio signals over said audio bus;
plural audio routing means, coupled between said audio bus and said plural audio destinations, for selecting said audio signals broadcasted by said audio source over said audio bus and for providing said signals to associated plural audio destinations; and
a digital communications link conveying digital messages between said audio source and said plural audio routing means;
wherein said plural audio routing means operate using distributed control, wherein each of said audio routing means includes autonomous means for deciding whether. or not to select said signals applied by said audio source to said dedicated time slot and provide said selected audio signals to at least one of said plural audio destinations associated therewith based at least partially on information conveyed over said digital communications link.
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Accused Products
Abstract
A distributed trunked radio frequency (RF) switching network (switch) distributes audio routing control and processing throughout the switch, thus avoiding a centralized mixing matrix, increasing fault tolerance and providing low routing request latency time. Each audio source (e.g., RF repeater transmitter, dispatch console microphone) is preassigned an audio channel on a time division multiplexed (TDM) digitized audio network or bus. The audio sources continually broadcast digitized audio signals to all other nodes over the TDM network. Audio routing is performed at the audio destinations (e.g., nodes associated with RF repeater receivers, dispatch console speakers) by selectively "listening" to active TDM network channels. In the preferred embodiment, audio is routed unidirectionally on an "as needed" basis (e.g., in response to radio transceiver "keys" and "unkeys"), and audio routing pathways may change dynamically during an on-going call.
45 Citations
45 Claims
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1. In a digitally trunked radio frequency communications system, a distributed audio routing arrangement for routing audio signals between an audio source and any of plural audio destinations, said distributed audio routing arrangement comprising:
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a time-division multiplexed digitized audio signal bus defining at least one time slot dedicated for use by said audio source; said audio source being coupled to said audio signal bus, said audio source applying digitized audio signals to said audio bus dedicated time slot to thereby broadcast audio signals over said audio bus; plural audio routing means, coupled between said audio bus and said plural audio destinations, for selecting said audio signals broadcasted by said audio source over said audio bus and for providing said signals to associated plural audio destinations; and a digital communications link conveying digital messages between said audio source and said plural audio routing means; wherein said plural audio routing means operate using distributed control, wherein each of said audio routing means includes autonomous means for deciding whether. or not to select said signals applied by said audio source to said dedicated time slot and provide said selected audio signals to at least one of said plural audio destinations associated therewith based at least partially on information conveyed over said digital communications link. - View Dependent Claims (2, 3, 4)
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5. In a digitally trunked radio frequency communications multisite system of a type having at least one audio source and plural audio destinations, a method for routing audio signals between said audio source and any of plural audio destinations utilizing a distributed control arrangement, said method comprising the following steps:
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(a) broadcasting audio signals from an audio over a time-division multiplexed (TDM) audio signal bus accessable to each of said plural destinations; (b) communicating digital messages indicating audio source activity information to each of said plural audio destinations; (c) deciding autonomously at each of said plural audio destinations, based at least in part on said audio source activity information, whether or not to receive and use said audio signals broadcasted by said audio source over said audio signal bus; and (d) at each of said plural destinations, providing Or not providing said broadcasted audio signals to corresponding audio destinations based on the result of the deciding step (c). - View Dependent Claims (6, 7)
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8. A distributed control audio routing arrangement for use in a digitally trunked radio frequency (RF) communications system of a type having a time-division multiplexed (TDM) audio bus carrying plural channels of digitized audio, said audio bus being coupled to plural audio destinations, said audio routing arrangement including for each said plural audio destinations:
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bus receiving means coupled to said audio bus for receiving digitized audio signals from each of said plural audio channels; a programmable lookup table providing values corresponding to said plural audio channels; digitized audio summing means, coupled to said bus receiving means and to said lookup table, for selecting a subset of said audio channels in response to the contents of said lookup table and for summing said selected subset of audio channels together; and means for outputting said sum for transmission as an audio signal over a communications link to a digitally trunked RF communications system site. - View Dependent Claims (9, 10)
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11. In a digitally trunked radio frequency communications system distributed control multisite network switch of a type coupling together plural audio sources/destinations so as to selectively route audio signals between said plural audio sources/destinations, a distributed control audio signal routing arrangement comprising:
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a time-division multiplexed digitized audio signal bus providing plural separate time slots; a digital message network for communicating status information between said plural audio sources/destinations; and an audio communications processor coupled to at least one of said audio sources/destinations and also coupled to said control message network and to said audio signal bus, said audio processor including audio source circuitry that broadcasts audio signals provided by said audio source/destination over a predetermined one of said plural time slots on said audio signal bus, said audio communications processor further including audio destination circuitry that autonomously determines whether or not to provide, to at least one of said plural audio sources/destinations associated therewith, audio signals carried by particular time slots on said audio bus based at least in part on said status information conveyed by said digital message network. - View Dependent Claims (12, 13, 14, 15, 16)
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17. In a radio frequency (RF) communications system including multiple digitally trunked RF transceiving sites for establishing radio contact with mobile and/or portable radio transceivers, a distributed control audio routing arrangement coupled between said multiple sites and comprising:
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at least one multiplexed digitized audio signal bus; at least one digital message communications link; multiple digitized-audio signal source means each associated with a respective one of said multiple digitally trunked RF transceiving sites, each for applying, to said audio signal bus, digitized audio signals received by an associated transceiving site; and multiple digitized-audio signal selection means each associated with a respective one of said multiple digitally trunked RF transceiving sites, said multiple signal selection means each coupled to said audio bus and to said digital message communications link, said multiple signal selection means each for providing distributed audio routing control by autonomously deciding whether or not to receive and convey to a transceiving site associated therewith, audio signals carried by said audio bus based at least in part on digital messages carried by said digital message communications link. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
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26. In a trunked radio frequency communications system having plural audio source/destination sites including multiple RF transceiving sites for establishing radio contact with mobile and/or portable radio transceivers, a distributed control audio signal routing arrangement for routing audio signals between said RF transceiving sites, comprising:
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at least one time-division multiplexed digitized audio signal bus carrying audio signals received by said RF transceiving sites; a message network for communicating digital trunking messages; at least one site interface controller associated with each of said transceiving sites, said site interface controller coupled to said message network for applying said digital trunking messages to said message network and for receiving said digital trunking messages from said message network; at least one audio channel processor coupled to said site interface controller, said audio channel processor applying audio signals received by an associated RF transceiving site to said audio signal bus, said audio channel processor selecting digitized audio signals carried by said audio bus in response to said digital trunking messages and providing said selected audio signals to an associated RF transceiving site. - View Dependent Claims (27, 28, 29, 30)
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31. In a radio frequency communications system having plural audio source/destination sites of various types including multiple RF transceiving sites for establishing radio contact with mobile and/or portable radio transceivers and having a distributed control multi-site digital information switching network, a distributed control audio information routing system for communicating digitized audio signals between said sites, said routing system comprising:
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at least one digitized-audio signal bus; a global message bus network for circulating call activity information throughout said multi-site digital information switching network; a controller module means associated with one of said multiple RF transceiving sites for autonomously selecting particular digitized audio signals carried on said audio bus based at least in part on call activity information circulated on said global message network; and at least one audio module means connected to said audio bus and responsive to said associated controller module for receiving and providing said particular digitized audio signals to an associated one of said multiple RF transceiving sites. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38)
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39. In a multi-site RF communications arrangement having a distributed control multisite digital information switching network including sites comprising conventional RF mobile communications systems and/or trunked communications systems, a distributed control audio information routing system for communicating digitized audio signals between switching network communication nodes associated with said sites via at least one time-division-multiplexed (TDM) audio bus, a portion of said distributed control located at a switching network node associated with each site comprising:
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a microcomputer controller for storing site identification information and channel/slot assignment information and for autonomously discerning which particular digital audio channels of a plurality of audio channels carried on said TDM audio bus contain active audio signals designated for a site assigned to said controller for selection for routing by an audio interfacing circuit; and at least one audio signal interfacing circuit associated with said controller and connected to said TDM audio bus for receiving digitized-audio signals and for placing digitized-audio signals onto said TDM audio bus, said interfacing circuit including channel selection means responsive to said controller for selecting said particular digital audio channels from said TDM audio bus and for providing audio signal information contained within said channels to a specific destination. - View Dependent Claims (40, 41, 42)
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43. In a digitally trunked radio frequency communications system including multiple RF transceiving sites for establishing radio contact between mobile and/or portable radio transceivers located in different ones of said multiple RF transceiving sites via trunked RF communications channels based on received and transmitted trunking control signals, a distributed control audio signal routing arrangement for rapidly and efficiently routing audio signals between said multiple RF transceiving sites, said arrangement comprising:
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at least one multiplexed digitized-audio signal bus; a message network for communicating trunking control messages; and at least one site interface controller associated with one of said multiple RF transceiving sites and coupled to said message network, said site interface controller for; (a) applying audio signals received by an associated RF transceiving site to said digitized-audio signal bus; (b) applying trunking control messages to said message network based on digital trunking signals received by an associated RF transceiving site; (c) receiving trunking control signals from said message network; and (d) autonomously determining whether or not to route audio signals carried by said bus to an associated RF transceiving site based at least in part on said trunking control signals received by said step (c). - View Dependent Claims (44, 45)
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Specification