Trunked radio repeater communication system

• US 6,529,486 B1
• Filed: 04/10/1998
• Issued: 03/04/2003
• Est. Priority Date: 04/11/1997
• Status: Expired due to Term

• Current Assignee: TRANSCRYPT INTERNATIONAL / E.F. JOHNSON COMPANY
• Original Assignee: TRANSCRYPT INTERNATIONAL/E.F. JOHNSON COMPANY
• Inventors: Smith, Rory A., Grindahl, Mervin L., Barnes, Keith W.
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): PHAN, MAN U
• Application Number:
  US09/058,345
• Time in Patent Office: 1,789 Days
• Field of Search: 370/327, 370/252, 370/276, 370/277, 370/278, 370/281, 370/295, 370/341, 370/426, 370/389, 455/15, 455/33, 455/9, 455/509, 455/517, 455/520
• US Class Current: 370/327
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 84/08 Trunked mobile radio systems
• CPC Class Codes: H04W 88/181 Transcoding devices; Rate adaptation devices

Abstract

A trunked radio repeater communication system capable of use in a networked system includes a plurality of distributive switches and a unique signaling protocol and a switching protocol for interconnecting the trunked transmission communications systems into a wide area network that provides an expanded feature set of radio communications capabilities. The trunked radio repeater system including a protocol supporting communications for repeaters and/or subscribers conducting communications using existing protocols, such as the Logic Trunked Radio (LTR) protocol and supporting additional special functions.

Claims

1. A communications protocol for a system of one or more repeaters and one or more subscribers, comprising:

a plurality of word formats for communications between the one or more repeaters and the one or more subscribers, each word format including;

a nine bit synchronization code for receiver synchronization;

a one bit type code indicating a first word format and a second word format and compatible with protocols using an area code to identify subscribership to a particular repeater site; and

a seven bit checksum code to error check communicated words; and

where the first word format further includes;

a five bit channel in use code to identify a channel in use;

a five bit home code identifying a home channel;

an eight bit group code providing a code for one or more groups of subscribers; and

a five bit free code identifying a free channel; and

wherein the second word format further includes function specific codes to perform a plurality of functions.

2. The communications protocol of claim 1, where the communications protocol is compatible with Logic Trunked Radio (LTR) communications.

3. The communications protocol of claim 1, where the first word format supports Logic Trunked Radio (LTR) communications.

4. The communications protocol of claim 1, where the channel in use code is used to provide receive channels and transmit channels.

5. The communications protocol of claim 4, where the receive channels and transmit channels have programmable relative offsets.

6. The communications protocol of claim 1, where transmissions of the first word format are recognized by Logic Trunked Radio (LTR) subscribers.

7. The communications protocol of claim 1, where transmissions of the second word format provide functions not supported by Logic Trunked Radio (LTR) subscribers.

8. The communications protocol of claim 1, where the type code comprises a type bit compatible with an AREA bit of a Logic Trunked Radio (LTR) protocol.

9. The communications protocol of claim 1, where the checksum code is inverted for transmissions from a subscriber to a repeater.

10. The communications protocol of claim 1, where the type code comprises a type bit matching a Logic Trunked Radio (LTR) AREA code of a repeater site for transmissions of word according to the first word format, the type bit inverted for transmission of the second word format.

11. The communications protocol of claim 1, where the type code comprises a type bit matching a Logic Trunked Radio (LTR) AREA code of a repeater site for transmissions of words according to the second word format, the type bit inverted for transmissions of the first word format.

12. The communications protocol of claim 1, where the type code comprises a type bit in a bit position equal to that of a Logic Trunked Radio (LTR) AREA bit.

13. The communications protocol of claim 1, where the home code, free code, and channel in use code are used in home channel aliasing.

14. The communications protocol of claim 1, where the home code, free code, group code and channel in use code are used in call grouping.

15. A radio incorporating the communications protocol of claim 1.

16. A subscriber incorporating the communications protocol of claim 1.

17. A repeater incorporating the communications protocol of claim 1.