Processor-to-processor communications protocol for a public service trunking system

• US 5,212,724 A
• Filed: 07/21/1992
• Issued: 05/18/1993
• Est. Priority Date: 08/14/1987
• Status: Expired due to Term

• Current Assignee: Com-Net Ericsson Canada Corp. (TE Connectivity Limited), Com-Net Ericsson Critical Radio Systems, Inc. (TE Connectivity Limited)
• Original Assignee: General Electric Company
• Inventors: Hattey, David I., Yurman, Bruno, Hughes, Houston H. III, Gordon, Robert T., Nazarenko, Dimitri M.
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Bost, Dwayne D.
• Application Number:
  US07/915,769
• Time in Patent Office: 301 Days
• Field of Search: 379/58, 379/63, 375/3, 370/58.1-58.3, 370/60, 370/99, 370/112, 455/9, 455/15, 455/33.1-33.4
• US Class Current: 455/560
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 25/06 Dc level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection
• 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

A downlink between a communications dispatch console and a digitally trunked radio repeater system site controller efficiently transfers message data between the site controller and the console over a standard 9.2 kilobit per second landline. A downlink trunking card identical in structure to trunking cards used in the preferred embodiment system for RF channel signal processing interfaces the site controller with the landline link. A similar trunking card on the other side of the landline link interfaces the dispatch console processor with the landline link. Message protocol and format is translated between the site controller and the landline link and between the landline link and the dispatch console. Data buffering at each end of the landline link maximizes data transfer rate over the landline, and in addition, a priority scheme insures that more important messages are transmitted over the downlink before less important messages. Retransmit-until-acknowledged protocol is used to insure reliable message transfer--and also to permit receiving units along the downlink to slow down transmitting units in order to avoid message traffic blockage.

Claims

1. A method of communicating digital signals between an RF repeater site controller and a telephone switch over a digital signal switchlink, said method including:

(1) transmitting distinct first and second site controller messages from said site controller over a high-speed data link connecting said site controller to a switchlink trunking card module;

(2) packing said first and second messages into a single message at said switchlink trunking card module;

(3) transmitting said single message from said switchlink trunking card module to a switch trunking card module over a lower speed landline communications link;

(4) unpacking said single message into distinct first and second console messages corresponding to said first and second site controller messages at said switch trunking card module; and

(5) transmitting said first and second console messages to said switch over a further high-speed data link connecting said switch trunking card module to said switch.

2. A method of communicating digital signals between an RF repeater site controller and a telephone switch over a digital signal switchlink, said method including:

(1) transmitting distinct first and second console messages from said switch over a high-speed data link connecting said switch to a switch trunking card module;

(2) packing said first and second messages into a single message at said switch trunking card module;

(3) transmitting said single message from said switch trunking card module to a switchlink trunking card module over a lower speed landline communications link;

(4) unpacking said single message into distinct first and second site controller messages corresponding to said first and second console messages at said switchlink trunking card module; and

(5) transmitting said first and second site controller messages to said site controller over a further high-speed data link connecting said switchlink trunking card module to said site controller.

3. A system for communicating digital signals between an RF repeater site controller and a telephone switching network over a digital signal switchlink including:

a first high-speed data link connecting said site controller to a switchlink trunking card means;

a landline communications link connecting said switchlink trunking card means to a switch trunking card means;

a second high-speed data link connecting said switch trunking card means to said telephone switching network;

said site controller including means for transmitting distinct first and second site controller message from said site controller to said switchlink trunking card means over said first high-speed data link;

said switchlink trunking card means for packing said first and second messages into a single message and for transmitting said single message to said switch trunking card means over said landline communications link;

said switch trunking card means for unpacking said single message into distinct first and second console messages corresponding to said first and second site controller messages and for transmitting said first and second console messages to said telephone switching network over said second high-speed data link.

4. A system for communicating digital signals between an RF repeater site controller and a telephone switching network over a digital signal downlink including:

a first high-speed data link connecting said site controller to a downlink trunking card means;

a landline communications link connecting said downlink trunking card means to a switch trunking card means;

a second high-speed data link connecting said switch trunking card means to said telephone switching network;

said telephone switching network including means for transmitting distinct first and second console messages to said switch trunking card means over said second high-speed data link;

said switch trunking card means for packing said first and second console messages into a single message and for transmitting said single message to said downlink trunking card means over said landline communications link;

said downlink trunking card means for unpacking said single message into distinct first and second site controller messages corresponding to said first and second console messages and for transmitting said first and second site controller messages to said site controller over said first high-speed data link.