Single channel autonomous digitally trunked RF communications system

• US 5,408,680 A
• Filed: 08/11/1992
• Issued: 04/18/1995
• Est. Priority Date: 08/11/1992
• Status: Expired due to Term

• Current Assignee: Pine Valley Investments, Inc. (L3Harris Technologies, Inc.)
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Childress, Jeffrey S., Hattey, David L., Dissosway, Marc A., Hughes, Houston H. III, Maedjaja, Samuel
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): FAILE, ANDREW I
• Application Number:
  US07/927,860
• Time in Patent Office: 980 Days
• Field of Search: 455/8-9, 455/11.1, 455/15, 455/16, 455/17, 455/19, 455/34.1, 455/34.2, 455/54.1, 455/54.2, 455/56.1, 455/62, 370/95.1, 370/95.3
• US Class Current: 455/15
• CPC Class Codes: H04B 7/15557 Selecting relay station operation mode, e.g. between amplify and forward mode, decode and forward mode or FDD - and TDD mode
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04W 4/12 Messaging; Mailboxes; Announcements
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 76/50 for emergency connections
• CPC Class Codes: H04W 84/08 Trunked mobile radio systems
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A single channel autonomous trunking ("SCAT") RF repeater transmits and receives on a single duplex RF channel. The repeater operates alternately in a control channel mode and in an assigned channel mode. Digital control channel signalling results in temporary assignment of the single channel for assigned channel signalling (e.g., mobile generated messages). A holdover time period following reversion of the channel to control channel signalling minimizes collisions and permits priority to be given to emergency communications. Low speed data subaudible digital signalling may be used to provide late entry capabilities.

Claims

1. An RF repeater system for providing RF communications among plural mobile or portable radio transceivers, said system comprising a duplex RF repeater capable of simultaneously receiving and transmitting, said RF repeater operating alternately in a control channel mode and in an assigned channel mode, said RF repeater transmitting digital signalling including channel assignment signalling when operating in said control channel mode, said RF repeater repeating or regenerating mobile or portable radio transmissions and transmitting subaudible signalling control data for at least late entry purposes when operating in said assigned channel mode.

2. A method of communicating over a single RF channel comprising the following steps:

when in a control channel operating mode, transmitting digital control signalling including a channel request message and a plurality of repetitive responsive channel assignment messages over said single channel to temporarily assign said single channel to at least one particular mobile or portable radio; and

when in an assigned channel operating mode, transmitting assigned channel signalling over said single channel in response to said channel assignment messages.

4. A method as in claim 2 further including reverting to said control channel operating mode upon termination of said temporary assignment.

8. A method as in claim 2 wherein said control channel signalling is time division multiplexed.

3. A method of communicating over a single RF channel comprising the following steps:

when in a control channel operating mode, transmitting digital control signalling including a channel request message and a responsive channel assignment message over said single channel to temporarily assign said single channel to at least one particular mobile or portable radio; and

when in an assigned channel operating mode, transmitting assigned channel signalling over said single channel in response to said channel assignment messages,

further including the step of inhibiting a mobile or portable radio other than said assigned mobile or portable radio from transmitting on said single channel when in said assigned channel operating mode.

5. A method of communicating over a single RF channel comprising the following steps:

when in a control channel operating mode, transmitting digital control signalling including a channel request message and a responsive channel assignment message over said single channel to temporarily assign said single channel to at least one particular mobile or portable radio; and

when in an assigned channel operating mode, transmitting assigned channel signalling over said single channel in response to said channel assignment messages,

further including reverting to said control channel operating mode upon termination of said temporary assignment;

further including inhibiting a mobile or portable radio from transmitting digital control channel signalling over said single channel during a hold-off time period subsequent to reverting to said control channel operating mode.

6. A method of communicating over a single RF channel comprising the following steps:

when in a control channel operating mode, transmitting digital control signalling including a channel request message and a responsive channel assignment message over said single channel to temporarily assign said single channel to at least one particular mobile or portable radio; and

when in an assigned channel operating mode, transmitting assigned channel signalling over said single channel in response to said channel assignment messages,

further including reverting to said control channel operating mode upon termination of said temporary assignment and controlling plural mobile or portable radios to transmit digital control channel signalling during different time periods following said reversion to minimize collisions over said single channel.

7. A method of communicating over a single RF channel comprising the following steps:

when in a control channel operating mode, transmitting digital control signalling including a channel request message and a responsive channel assignment message over said single channel to temporarily assign said single channel to at least one particular mobile or portable radio; and

when in an assigned channel operating mode, transmitting assigned channel signalling over said single channel in response to said channel assignment messages,

further including reverting to said control channel operating mode upon termination of said temporary assignment and reserving a time period following said reversion for emergency related transmissions.

9. A method of communicating over a single RF channel comprising the following steps:

when in a control channel operating mode, transmitting digital control signalling including a channel request message and a responsive channel assignment message over said single channel to temporarily assign said single channel to at least one particular mobile or portable radio; and

when in an assigned channel operating mode, transmitting assigned channel signalling over said single channel in response to said channel assignment messages,

further including the step of redundantly transmitting said channel assignment message to increase the likelihood of detection by said mobile or portable radio.

10. A method of communicating over a single RF channel comprising the following steps:

when in a control channel operating mode, transmitting digital control signalling including a channel request message and a responsive channel assignment message over said single channel to temporarily assign said single channel to at least one particular mobile or portable radio; and

when in an assigned channel operating mode, transmitting assigned channel signalling over said single channel in response to said channel assignment messages, and

wherein said assigned channel signalling transmitting step includes transmitting low speed data for late entry purposes.

11. A method of upgrading a single channel RF repeater communications system to a plural channel RF repeater communications system without having to replace an installed base of mobile radios comprising:

converting a combined control and assigned channel repeater to operate alternately in a dedicated manner on a dedicated control channel or an assigned channel; and

adding at least one further repeater for operation in a dedicated manner on said dedicated control channel or on said assigned channel.

12. A method of operating a wide area RF communications system comprising:

logging in, with a mobile, to a multichannel digitally trunked repeater site having a dedicated RF digital control channel and at least one further RF channel available for temporary assignment to mobiles; and

subsequently logging in, with said same mobile, to a single channel digitally trunked repeater site having a single RF channel that operates alternately in a digital control channel mode and in an assigned channel mode.

13. A wide area RF communications system comprising:

a multichannel digitally trunked repeater site having a dedicated RF digital control channel and at least one further RF channel available for temporary assignment to mobiles;

a single channel digitally trunked repeater site having a single RF channel that operates alternately in a digital control channel mode and in an assigned channel mode; and

a multisite switch that routes digital control messages to each of said multichannel site and said single channel repeater site.

14. An RF repeater including:

an RF transmitter for transmitting RF signals over an output frequency;

an RF receiver for receiving RF signals over an input frequency; and

control means coupled to said RF transmitter and said RF receiver, said control means alternately;

(a) controlling said transmitter to transmit and said receiver to receive digital control signalling to/from plural mobile radios; and

(b) controlling said transmitter to transmit and said receiver to receive assigned channel signalling including low speed data signals to/from a subset of said plural mobile radios, said subset being specified by said digital control signalling.

15. A method of transmitting RF signals in accordance with a predetermined transmission signalling protocol, said method including:

transmitting digital control signalling including a channel assignment message over an RF channel to temporarily assign said RF channel to at least one mobile radio; and

transmitting assigned channel signalling included repeated or regenerated mobile transmissions and subaudible control data for at least late entry purposes over said assigned RF channel.