Dynamic address allocation within RF trunking multisite switch

• US 5,603,086 A
• Filed: 05/12/1993
• Issued: 02/11/1997
• Est. Priority Date: 02/22/1991
• Status: Expired due to Term

• Current Assignee: Pine Valley Investments, Inc. (L3Harris Technologies, Inc.)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Cree, Timothy F., Imron, Win A., Brame, Charles P.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): LE, THANH C
• Application Number:
  US08/059,670
• Time in Patent Office: 1,371 Days
• Field of Search: 455/34.1, 455/34.2, 455/53.1, 455/17, 455/54.1, 455/56.1, 370/85.7, 370/95.1, 340/825.07, 340/825.08, 340/825.5, 340/825.52, 375/85.1, 375/85.2, 375/85.3, 375/85.4, 375/94.1
• US Class Current: 455/520
• 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. 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.

Claims

1. A method of operating an RF trunking multisite switch for coordinating radio communications between plural repeaters located in different geographical areas which control RF communications between plural RF transceivers, said switch having a distributed architecture of nodes operatively coupled to a message bus and a time division multiplex audio bus having multiple audio channels wherein each node comprises a computer controller and an associated memory unit having an address table, said method comprising the steps of:

a. assigning a node to each of the repeaters located in different geographical areas, each node processing communications with its assigned repeater;

b. each node automatically selecting a requested address from a plurality of possible addresses for identifying that node on the message bus and broadcasting that address to the other nodes over the message bus;

c. upon receiving an address request broadcast by another node, each node comparing the broadcast address to its own address, and broadcasting an address denial message over the message bus to the another node when the compared addresses are the same;

d. when each node receives an address denial message for its requested address, returning to step (b), automatically selecting another address, and broadcasting the another address to other nodes; and

e. writing selected addresses associated with all nodes for which an address denial message is not broadcast in the address table of each node, wherein communications are routed between RF transceivers in different geographical areas through the switch, using one of the multiple audio channels on the time division multiplex bus, to nodes corresponding to the repeaters located in those different geographical areas based on the addresses in the address tables of each node.

2. The method according to claim 1, wherein each repeater coordinates RF communications of mobile transceivers in an associated geographic area which partially overlaps geographic areas associated with other of the repeaters.

3. In an RF thinking multisite switch for enabling radio communications between plural site transceiver stations located in different geographical site areas which control RF communications between plural RF mobile/portable radios located in those different geographical site areas so that one radio in one geographical site area may communicate with another radio in another geographical site area, each site transceiver station having plural transceivers and a site controller and said switch having a distributed architecture of nodes operatively coupled to a message bus and a time division multiplex bus, a method comprising the steps of:

assigning a node to each of the site transceiver stations, each node controlling communications between said switch and its site transceiver station; and

each node automatically selecting a node address from one of a plurality of possible node addresses and broadcasting a requested address message including the selected node address to the other nodes over the message bus, wherein upon receiving the requested address message broadcast by another node, each node compares the broadcast address to its own address, and broadcasts an address denial message over the message bus to the another node when the compared addresses are the same.

4. The method according to claim 3, further comprising:

when the another node receives the address denial message for its requested messaging address, returning to step (b), automatically selecting another node address, and broadcasting another messaging address to the other nodes over the message bus.

5. The method according to claim 4, further comprising the step of:

e. writing selected node addresses that have not been denied in an address table of each node.

6. The method according to claim 5, further comprising the step of:

routing messages to specific nodes using the node addresses stored in the address table.

7. A multisite trunked radio communications system, comprising:

plural mobile/portable RF radios;

plural base stations located in different corresponding geographical areas, each base station including plural transceivers for controlling RF communications with one or more radios in the base station'"'"'s corresponding geographical area;

a multisite switch for muting radio communications between the base stations so that radios in different geographical areas can communicate including;

a message bus;

a time division multiplex bus having multiple channels; and

a distributed architecture of nodes, each node having a computer and operatively coupled to the message bus and the time division multiplex audio bus and being assigned to and interfacing communications with one of the base stations, wherein each node automatically determines its own node address from a plurality of possible node addresses to be used in routing signals on the massage bus or the time division multiplex bus to that node, transmits over the message bus a requested address message including the determined node address to the other nodes,

compares an address included in received address message requests transmitted over the message bus to its own node address, and transmits an address denial message over the control message bus when compared addresses are the same.

8. The system according to claim 7, wherein each node generates a different messaging address if an address denial message is received over the control message bus and transmits the different address message to the other nodes.

9. The system according to claim 8, each node further comprising:

a memory for storing node generated addresses which were not denied in an address table.

10. The system according to claim 7, wherein each node generates its own address randomly.

11. A multisite trunked radio communication system, comprising:

plural mobile/portable RF radios;

plural trunked radio sites including plural transceivers located in different corresponding geographical areas RF communications with one or more radios in the site'"'"'s corresponding geographical area, a specific communication channel being assigned to a communication involving a radio in the site'"'"'s corresponding geographical area independently of communication channel assignments in other sites; and

a multisite switch having a distributed architecture for networking the sites together to dynamically establish an audio channel connecting one site with one or more other sites so that a radio in one geographical area may communicate with another radio in another geographical area including;

a message bus;

a time division multiplex bus having multiple channels for routing audio and data signals from one site to another site;

plural nodes, each node having a computer and operatively coupled to the message bus and the time division multiplex bus and being assigned to and interfacing communications with one of the sites, wherein each node dynamically generates an address, transmits over the message bus a requested address message including the generated address to the other nodes, compares address message requests received from over the message bus to its own address transmits an address denial message over the message bus when compared addresses are the same, and adopts the generated address if an address denial message is not received over the message bus within a preset time after the requested address memory is transmitted, and wherein a communication between radios located in different geographical areas is routed through the switch over one of the channels on the time division multiplex bus to/from nodes corresponding to the base stations in those geographical areas using the node generated addresses.

12. The system according to claim 11, wherein each node generates its own address randomly.

13. A system according to claim 11, wherein each node generates a different message address when the address denial message is received over the message bus and transmits the different address message to the other nodes.'"'"'