Distributed multisite system architecture

• US 5,392,278 A
• Filed: 02/22/1991
• Issued: 02/21/1995
• Est. Priority Date: 08/28/1990
• Status: Expired due to Term

• Current Assignee: Pine Valley Investments, Inc. (L3Harris Technologies, Inc.)
• Original Assignee: Ericsson GE Mobile Communications Inc (Telefonaktiebolaget LM Ericsson)
• Inventors: Gulliford, Philip C., Brame, Charles P., Imron, Wim A., Teel, James L.
• Primary Examiner(s): MARCELO, MELVIN C
• Application Number:
  US07/658,844
• Time in Patent Office: 1,460 Days
• Field of Search: 370/67, 370/85.1, 370/85.9, 370/85.7, 370/85.11, 370/94.1, 370/95.1, 370/95.3, 455/56.1, 455/33.1, 455/33.4, 379/58, 379/59, 379/63
• US Class Current: 370/312
• CPC Class Codes: H04W 4/10 Push-to-Talk [PTT] or Push-On-Call services
• CPC Class Codes: H04W 76/45 for Push-to-Talk [PTT] or Push-to-Talk over cellular [PoC] services
• CPC Class Codes: H04W 84/08 Trunked mobile radio systems

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.

Claims

1. A local area network for a radio frequency multicasting system including a multisite switch comprising:

a first microprocessor controlled node coupled through a first data link and to a first trunked audio link to a first transmitter;

a second microprocessor controlled node coupled through a second data link and to a second trunked audio link to a second transmitter, where said second transmitter is in a separate site than is said first transmitter;

an audio bus including a plurality of slots conveying audio communications between said transmitters, said audio bus being operatively connected to the first and second microprocessor controlled nodes, said nodes controlling slot assignments for said communications.

2. A local area network as in claim 1 further comprising a third microprocessor controlled node coupled to a dispatcher console through a third data link and a third trunked audio link.

3. A local area network as in claim 2 wherein said microprocessor controlled nodes are structurally substantially identical.

4. A local area network as in claim 3 wherein said microprocessor controlled nodes are structurally interchangeable.

5. A local area network as in claim 1 wherein said first and second nodes have a dynamic addressing means for assigning unique addresses to said nodes by each node selecting its own unique address.

6. A local area network for a radio frequency multicasting system including a multisite switch comprising:

a first microprocessor controlled node coupled through a first data link and to a first trunked audio link to a first transmitter;

a second microprocessor controlled node coupled through a second data link and to a second trunked audio link to a second transmitter, where said second transmitter is in a separate site than is said first transmitter;

an audio bus operatively connected to the first and second microprocessor controlled nodes, said bus including a plurality of slots conveying audio communications between said transmitters, said nodes controlling slot assignments for said communications; and

a message bus operatively coupled to said first and second nodes, said nodes repeatedly sending status messages on the message bus slot,

whereby said nodes maintain a bus/slot bit map representative of the status of each audio slot and a redundant message discard means for discarding slot status messages redundant to a previously received slot status message.

7. A local area network for a radio frequency multicasting system providing communications between mobile user units and groups of user units, said system including a multisite switch comprising:

a first microprocessor controlled node coupled through a first data link and to a first trunked audio link to a first transmitter;

a second microprocessor controlled node coupled through a second data link and to a second trunked audio link to a second transmitter, where said second transmitter is in a separate site than is said first transmitter;

an audio bus operatively connected to the first and second microprocessor controlled nodes, said bus including a plurality of slots conveying audio communications between said transmitters, said nodes controlling slot assignments for said communications and the microprocessor controlled nodes include databases for unit and group counts,

said unit and group counts are indicative of mobile user units and user units assigned to a particular group in a broadcast area for a transmitter coupled to a respective node.

8. In a radio frequency multicasting system of the type having a central switch controlled by a local area network of nodes each having one or more microprocessor supported audio cards connected to a slotted audio bus within the switch, a controller card coupled to said audio cards and to a message bus within said switch, and plurality of radio frequency site controllers each coupled to an individual switch node, a method of establishing audio communications between said site controllers and through said switch comprising the steps of:

receiving a channel assignment at a first node of the switch from a first site controller;

generating an audio slot assignment message in said first node and placing the slot assignment message on the message bus;

upon receipt of the slot assignment message from the bus, a second node sending a channel request to a second site controller operatively coupled to said second node;

sending a second channel assignment to the second node from the second site controller and

sending audio signals from the first site controller to the second site controller over the assigned audio slot on the switch.

9. A local area network for a radio frequency multicasting system including a multisite switch comprising:

a first microprocessor controlled node coupled through a first data link and to a first trunked audio link to a first transmitter;

a second microprocessor controlled node coupled through a second data link and to a second trunked audio link to a second transmitter, where said second transmitter is in a separate site than is said first transmitter;

an audio bus operatively coupled to the first and second microprocessor controlled nodes, said bus including a plurality of slots conveying audio communications between said transmitters, said nodes controlling slot assignments for said communications and said nodes store databases of user groups, wherein each of said user groups identifying individual units in said system assigned to each group.

10. A local area network for a radio frequency multicasting system including a multisite switch comprising:

a first microprocessor controlled node coupled through a first data link and to a first trunked audio link to a first transmitter;

a second microprocessor controlled node coupled through a second data link and to a second trunked audio link to a second transmitter, where said second transmitter is in a separate site than is said first transmitter;

an audio bus operatively coupled to the first and second microprocessor controlled nodes, said bus including a plurality of slots conveying audio communications between said transmitters, said nodes controlling slot assignments for said communications and said nodes store databases identifying mobile units within the area covered by the transmitter coupled to the respective node.

11. A local area network for a radio frequency multicasting system including a multisite switch comprising:

a first processor controlled node coupled through a first data link and to a first trunked audio link to a first transmitter;

a second processor controlled node coupled through a second data link and to a second trunked audio link to a second transmitter, where said second transmitter is in a separate site than is said first transmitter;

an audio bus operatively coupled to the first and second processor controlled nodes, said bus including a plurality of slots conveying audio communications between said transmitters, said nodes controlling slot assignments for said communications.