Method and apparatus for trunked radio repeater communications with backwards compatibility

• US 6,374,115 B1
• Filed: 04/10/1998
• Issued: 04/16/2002
• Est. Priority Date: 05/28/1997
• Status: Expired due to Term

• Current Assignee: Transcrypt Internationall E F Johnson Company
• Original Assignee: Transcrypt Internationall E F Johnson Company
• Inventors: Smith, Rory A., Grindahl, Mervin L., Barnes, Keith W.
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): PEREZ GUTIERREZ, RAFAEL
• Application Number:
  US09/058,678
• Time in Patent Office: 1,467 Days
• Field of Search: 455/517, 455/519, 455/520, 455/518, 455/507, 455/426, 455/524
• US Class Current: 455/520
• 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
• CPC Class Codes: H04W 92/02 Inter-networking arrangements

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 synchronization code for receiver synchronization;

a 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 checksum code to error check communicated words; and

where the first word format further includes;

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

a home code identifying a home channel;

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

a 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 words according to the first word format, the type bit inverted for transmissions 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.

22. A trunked radio network, comprising:

a plurality of subscribers;

a plurality of repeaters, wherein at least one repeater uses the communications protocol of claim 1;

two or more switches interconnecting repeaters at two or more sites; and

one or more call routers interconnecting the two or more switches.

23. The trunked radio network of claim 22, wherein at least one subscriber uses the communications protocol of claim 1.

24. The trunked radio network of claim 22, wherein Logic Trunked Radio (LTR) communications are supported.

25. The trunked radio network of claim 22, comprising at least one subscriber communicating using Logic Trunked Radio (LTR) transmissions.

26. The trunked radio network of claim 22, comprising one or more repeaters communicating using Logic Trunked Radio (LTR) transmissions.

27. The trunked radio network of claim 22, comprising a call processor/subscriber system manager for each switch of the two or more switches.

18. 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 synchronization code for receiver synchronization;

a type code indicating a first word format and a second word format and compatible with a Logic Trunked Radio (LTR) protocol AREA bit, where the type code related to an LTR AREA code of a repeater site for transmissions of words according to the first word format, the type code inverted for transmissions of the second word format; and

a checksum code to error check communicated words, wherein the checksum code is inverted for transmissions from a subscriber to a repeater of words of the second word format; and

where the first word format further includes;

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

a home code identifying a home channel;

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

a free code identifying a free channel; and

wherein the first word format supports LTR functions and the second word format supports function specific codes to perform a plurality of functions and such that the communications protocol is compatible with Logic Trunked Radio (LTR) communications.

19. A radio incorporating the communications protocol of claim 18.

20. A subscriber incorporating the communications protocol of claim 18.

21. A repeater incorporating the communications protocol of claim 18.

28. A trunked radio network, comprising:

a plurality of subscribers;

a plurality of repeaters, wherein at least one repeater uses the communications protocol of claim 18;

two or more switches interconnecting repeaters at two or more sites; and

one or more call routers interconnecting the two or more switches.

29. The trunked radio network of claim 28, wherein at least one subscriber uses the communications protocol of claim 18.

30. The trunked radio network of claim 28, wherein Logic Trunked Radio (LTR) communications are supported.

31. The trunked radio network of claim 28, comprising at least one subscriber communicating using Logic Trunked Radio (LTR) transmissions.

32. The trunked radio network of claim 28, comprising one or more repeaters communicating using Logic Trunked Radio (LTR) transmissions.

33. The trunked radio network of claim 28, comprising a call processor/subscriber system manager for each switch of the two or more switches.

34. A method of communications, comprising:

transmitting words having a same number of bits as Logic Trunked Radio (LTR) words; and

transmitting a type code in bit position of an LTR area code, the type code matching an LTR AREA code for a particular site for transmission of normal words and the type code opposite of the LTR AREA code for transmission of special function words.

35. The method of claim 34, further comprising the act of inverting a checksum for communications of special function words from a subscriber to a repeater to avoid misinterpretation of the special function words.