Conventional base station interface architecture for RF trunking multisite switch

• US 5,241,537 A
• Filed: 06/04/1991
• Issued: 08/31/1993
• Est. Priority Date: 06/04/1991
• Status: Expired due to Term

• Current Assignee: Pine Valley Investments, Inc. (L3Harris Technologies, Inc.)
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Gulliford, Philip C., Brame, Charles P., Imron, Wim A.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): MARCELO, MELVIN C
• Application Number:
  US07/709,987
• Time in Patent Office: 819 Days
• Field of Search: 370/67, 370/68.1, 370/79, 370/84, 370/85.1, 370/110.1, 370/110.2, 455/56.1
• US Class Current: 370/341
• 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

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.

Claims

1. A radio frequency (RF) communications network having digitally trunked RF communication systems and a conventional non-trunked RF communication system comprising:

an audio routing arrangement for routing trunked audio signals between digital trunked RF communication systems, said audio routing arrangement including a distributed architecture multisite switch having a plurality of nodes operatively coupled to an audio bus, said nodes each having a processor controlling the node and audio routing through the node, and

a conventional interface adapter interfacing said conventional non-trunked radio frequency (RF) system to a processor controlled conventional node in said audio routing arrangement, said adapter linking audio signals on conventional non-trunked RF channels to trunked RF communications through said audio bus.

2. A RF communications network as in claim 1 wherein said conventional interface adapter comprises:

a conventional interface providing a pathway between non-trunked audio signals and digitally trunked audio signals, and

a conventional control interface converting digital commands from said digitally trunked RF communication system into conventional control commands for said conventional non-trunked RF communication system.

3. A RF communications network as in claim 2 wherein said conventional interface comprises a voice activated device for detecting the presence of voice audio signals on a channel of said conventional communication system, said voice activated device signalling conventional control interface when voice audio is present on a conventional non-trunked channel.

4. A RF communications network as in claim 2 wherein said conventional interface comprises means for summing conventional control signals with audio signals going to said conventional non-trunked RF communications system.

5. A RF communications network as in claim 2 wherein said conventional control interface comprises:

channel assignment means for signally said digitally trunked RF systems when a voice audio signal is present on a channel from said conventional non-trunked RF communication system, and

keying means for signalling said conventional interface means to establish an audio pathway for a particular call from said trunked RF communication system to said conventional non-trunked RF communication system.

6. A RF communications network as in claim 2 wherein said conventional non-trunked RF communications system comprises a base station operatively coupled to said conventional interface and said conventional control further comprises means for providing conventional control tones or DC currents to control said base station, said tones or DC currents being provided in response to digital commands from said digitally trunked RF communications system.

7. A method for interfacing a conventional non-trunked radio frequency (RF) communication system to a network of digitally trunked RF communication systems having a multisite switch comprising an audio bus, a plurality of nodes each having a processor routing audio to the trunked systems, and said audio bus and a conventional processor controlled node routing audio between said audio bus and a conventional interface adapter in said switch and operatively connected to the conventional non-trunked RF communication system, said method comprising the following steps by the multisite switch:

(a) detecting an incoming voice signal on one of a plurality of conventional non-trunked audio sources coupled to the conventional interface adapter;

(b) broadcasting the incoming voice signal on an audio slot within the switch;

(c) issuing a digital channel request message from the conventional node to the other nodes within the switch identifying the audio slot having the incoming voice signal, and

(d) at least one of the other nodes linking a trunked audio destination to the audio slot having the incoming voice signal.

8. A method for interfacing a conventional non-trunked radio frequency (RF) communication system to a network of digitally trunked RF communication systems having a multisite switch comprising an audio bus, a plurality of processor controlled nodes linking audio between the audio bus and the trunked systems and a conventional processor controlled node routing audio between the audio bus and a conventional interface adapter operatively connected from the switch to the conventional non-trunked RF communication system, said method comprising the following steps by the multisite switch:

(a) a first switch node broadcasting a digitally trunked audio signal on an audio slot within the switch;

(b) the first switch node issuing a digital channel request message within the switch identifying the audio slot having the audio signal;

(c) in response to the channel request message, the conventional node and conventional interface adapter keying a conventional channel link to activate the channel;

(d) the conventional node coupling the conventional channel link to the audio slot having the trunked audio signal and the conventional interface adaptor converting the trunked audio signal into a non-trunked audio signal.