Signalling method for establishing trunked communication

• US 4,723,264 A
• Filed: 06/19/1987
• Issued: 02/02/1988
• Est. Priority Date: 06/19/1987
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Zdunek, Kenneth J., Sasuta, Michael D.
• Primary Examiner(s): Lev, Robert
• Application Number:
  US07/064,907
• Time in Patent Office: 228 Days
• Field of Search: 455/33, 455/58, 455/38, 455/56, 379/58, 379/63, 379/57, 379/60, 379/59
• US Class Current: 455/410
• CPC Class Codes: H04W 84/08 Trunked mobile radio systems

Abstract

A trunked communication signalling method is provided by a unifying signalling protocol in which subscribers request communication channels using only their individual IDs encoded into a single ISWs. The central decodes the call request, extracts the requesting subscriber'"'"'s individual ID, which is cross referenced to determine the subscriber'"'"'s talk-group affiliation(s). If the requesting subscriber'"'"'s affiliation(s) are not known, the central commands the subscriber to transmit its affiliation using dual ISW signalling. In another aspect of the present invention, each subscriber automatically informs the central of a change in talk-group affiliation, thereby providing continual affiliation updates. In this way, many thousand subscribers are afforded access to a single trunked system, and control channel traffic congestion is minimized.

Claims

1. In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units organized in groups and each subscriber having at least an individual identification code and a talk-group affiliation, said subscribers constructed and arranged to communicate information on any of the communication channels, a method for any of the plurality of subscribers to request access to a communication channel comprising the steps of:

(a) transmitting a message comprising at least a call request information word having a predetermined bit length and being organized in fields, wherein a first field represents the subscriber'"'"'s individual identification code, and a second field represents the type of call requested;

(b) receiving a message comprising at least channel grant information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing a channel assignment.

2. In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units organized in groups and each subscriber having at least an individual identification code and a talk-group affiliation, said subscribers constructed and arranged to communicate information on any of the communication channels, a method for any of the plurality of subscribers to request access to a communication channel comprising the steps of:

(a) transmitting a message comprising at least a call request information word having a predetermined bit length and being organized in fields, wherein a first field represents the subscriber'"'"'s individual identification code, and a second field represents the type of call requested;

(b) receiving a message comprising at least a command information word having a predetermined bit length and being organized in fields, wherein a first field represents said subscriber'"'"'s individual identification code, and a second field represents a predetermined command code;

(c) transmitting a message comprising at least call request information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing said type of call requested;

(d) receiving a message comprising at least channel grant information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing a channel assignment.

3. In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units organized in groups and each subscriber having at least an individual identification code and a talk-group affiliation, said subscribers constructed and arranged to communicate information on any of the communication channels, a subscriber unit, comprising:

means for transmitting a message comprising at least a call request information word having a predetermined bit length and being organized in fields, wherein a first field represents the subscriber'"'"'s individual identification code, and a second field represents the type of call requested;

means for receiving a message comprising at least channel grant information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing a channel assignment.

4. In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units organized in groups and each subscriber having at least an individual identification code and a talk-group affiliation, said subscribers constructed and arranged to communicate information on any of the communication channels, a subscriber unit comprising:

means for transmitting a message comprising at least a call request information word having a predetermined bit length and being organized in fields, wherein a first field represents the subscriber'"'"'s individual identification code, and a second field represents the type of call requested;

means for receiving a message comprising at least a command information word having a predetermined bit length and being organized into fields, wherein a first field represents said subscriber'"'"'s individual identification code, and a second field represents a predetermined command code;

means for transmitting a message comprising at least call request information words each having a predetermined bit length and being organized into fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing said type of call requested;

means for receiving a message comprising at least channel grant information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing a channel assignment.

5. In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units organized in groups and each subscriber having at least an individual identification code and a talk-group affiliation, said subscribers constructed and arranged to communicate information on any of the communication channels, a method for any of the plurality of subscribers to request access to a communication channel comprising the steps of:

at any of the subscriber units;

(a) transmitting a message comprising at least a call request information word having a predetermined bit length and being organized in fields, wherein a first field represents the subscriber'"'"'s individual identification code, and a second field represents the type of call requested;

(b) receiving a message comprising at least channel grant information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing a channel assignment;

at the central controller;

(a) receiving said message comprising at least a call request information word having a predetermined bit length and being organized in fields, wherein a first field represents the subscriber'"'"'s individual identification code, and a second field represents the type of call requested;

(b) cross-referencing said subscriber'"'"'s individual identification code to provide the subscriber'"'"'s talk-group affiliation;

(c) transmitting said message comprising at least channel grant information words each having a predetermined bit length and being organized into fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing a channel assignment.

6. The method of claim 5, which includes the central controller step of:

(a1) determining whether said subscriber'"'"'s individual identification code is valid.

7. The method of claim 5, which includes the central controller step of transmitting a message comprising at least a command information word having a predetermined bit length and being organized in fields, wherein a first field represents said subscriber'"'"'s individual identification code, and a second field represents a predetermined command code, if the central is unable to determine said subscriber'"'"'s talk-group affiliation.

8. In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units organized in groups and each subscriber having at least an individual identification code and a talk-group affiliation, said subscribers constructed and arranged to communicate information on any of the communication channels, a method for any of the plurality of subscribers to request access to a communication channel comprising the steps of:

at any of the subscriber units;

(a) transmitting a message comprising at least a call request information word having a predetermined bit length and being organized in fields, wherein a first field represents the subscriber'"'"'s individual identification code, and a second field represents the type of call requested;

(b) receiving a message comprising at least a command information word having a predetermined bit length and being organized in fields, wherein a first field represents said subscriber'"'"'s individual identification code, and a second field represents a predetermined command code;

(c) transmitting a message comprising at least call request information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing said type of call requested;

(d) receiving a message comprising at least channel grant information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing a channel assignment;

at the central controller;

(a) receiving said message comprising at least a call request information word having a predetermined bit length and being organized in fields, wherein a first field represents the subscriber'"'"'s individual identification code, and a second field represents the type of call requested;

(b) cross-referencing said subscriber'"'"'s individual identification code thereby determining the absence of the subscriber'"'"'s talk-group affiliation;

(c) transmitting said message comprising at least a command information word having a predetermined bit length and being organized in fields, wherein a first field represents said subscriber'"'"'s individual identification code, and a second field represents a predetermined command code;

(d) receiving said message comprising at least call request information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group identification code, and a second field representing said type of call requested;

(e) transmitting said message comprising at least channel grant information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing a channel assignment.

9. The method of claim 8, which includes the central controller step of:

(a1) determining whether said subscriber'"'"'s individual identification code is valid.

10. In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units organized in groups and each subscriber having at least an individual identification code and a talk-group affiliation, said subscribers constructed and arranged to change at least their talk-group affiliation at will and to communicate information on any of the communication channels, a method for any of the plurality of subscribers to update the central of a talk-group affiliation change comprising the steps of:

(a) transmitting, automatically, following selection of another talk-group affiliation, a message comprising at least update information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing a predetermined code word;

(b) receiving a message comprising at least an acknowledge information word having a predetermined acknowledge code.

11. In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units organized in groups and each subscriber having at least an individual identification code and a talk-group affiliation, said subscribers constructed and arranged to change at least their talk-group affiliation at will and to communicate information on any of the communication channels, a subscribers unit comprising:

means for transmitting, automatically, following selection of another talk-group affiliation, a message comprising at least update information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing a predetermined code word;

means for receiving a message comprising at least an acknowledge information word having a predetermined acknowledge code.

12. In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units organized in groups and each subscriber having at least an individual identification code and a talk-group affiliation, said subscribers constructed and arranged to change at least their talk-group affiliation at will and to communicate information on any of the communication channels, a method for any of the plurality of subscribers to update the central of a talk-group affiliation change comprising the steps of:

(a) transmitting, automatically, with the subscriber'"'"'s next transmission, a message comprising at least update/call request information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing the type of call requested;

(b) receiving a message comprising at least channel grant information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing a channel assignment.

13. In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units organized in groups and each subscriber having at least an individual identification code and a talk-group affiliation, said subscribers constructed and arranged to change at least their talk-group affiliation at will and to communicate information on any of the communication channels, a subscriber unit comprising:

means for transmitting, automatically, with the subscriber'"'"'s next transmission, a message comprising at least update/call request information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing the type of call requested;

means for receiving a message comprising at least channel grant information words each having a predetermined bit length and being organized in fields, wherein;

(i) a first word comprises a first field representing said subscriber'"'"'s individual identification code, and a second field representing a predetermined digital word;

(ii) a second word comprises a first field representing said subscriber'"'"'s talk-group affiliation, and a second field representing a channel assignment.