Hardware interface and protocol for a mobile radio transceiver

• US 5,109,543 A
• Filed: 12/13/1989
• Issued: 04/28/1992
• Est. Priority Date: 08/14/1987
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: General Electric Company
• Inventors: Dissosway, Marc A., Childress, Jeffrey S.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Chin, Wellington
• Application Number:
  US07/449,790
• Time in Patent Office: 867 Days
• Field of Search: 455/170, 455/153, 455/160
• US Class Current: 455/170.1
• CPC Class Codes: H04L 1/0078 Avoidance of errors by organising the transmitted data in a format specifically designed to deal with errors, e.g. location forward error control, e.g. FEC, CRC H04L1/004; adaptive formatting H04L1/0006; mappings H04L27/00
• CPC Class Codes: H04L 1/1685 the supervisory signal being transmitted in response to a specific request, e.g. to a polling signal
• CPC Class Codes: H04L 2001/0092 Error control systems characterised by the topology of the transmission link
• 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 system and method for communicating control signals between a digital mobile transceiver, a digital control head, and a mobile data terminal over a common serial peripheral bus uses a message protocol and architecture which is efficient and yet provides great versatility and functionality without adding undue complexity. As mobile data terminals are becoming increasing important in digital trunked repeater systems, the efficiency provided by the signalling protocol disclosed herein (which is optimized for mobile data terminal messages) is a very important advantage.

Claims

1. A method of communicating digital data messages between a control head including a rotary switch and a digital mobile radio frequency transceiver over a serial data bus, said method including:

(1) sensing changes in position of said control head rotary switch;

(2) if said sensing step reveals said switch position has changed position, determining the direction of said position changes; and

(3) transmitting a multi-bit length message from said control head to said transceiver over said serial data bus whenever said sensing step (1) reveals said switch position has changed, including transmitting a single bit within said message having a first logic level if said determining step determines said switch position changed in a first direction and having a second logic level if said determining step reveals said switch position changed in a second direction opposite said first direction.

2. An apparatus for communicating digital data signals between a digital mobile radio frequency transceiver and a control head including a rotary switch over a serial data bus, comprising:

digital logic control means for detecting changes in position of said control head rotary switch and for indicating the direction of said position changes,

wherein said digital control means further comprises means for forming and transmitting a switch position message from said control head to said transceiver over said serial data bus whenever said digital logic control means detects that said switch position has changed, and

wherein said message comprsies a sequence of bits and includes a single bit having a first logic level if said switch position is changed in a first direction and having a second logic level if said switch is changed in a second direction opposite to said first direction.

3. An apparatus for communicating digital data signals between a digital mobil radio frequency transceiver and a control head as in claim 2, wherein said digital logic control means comprises a microprocessor controller.

4. An apparatus for communicating digital data signals between a digital mobil radio frequency transceiver and a control head as in claim 2, wherein said siwtch position message comprises a plurality of serial data fields including:

a message-type field;

a unit ID field;

a data-type field;

a data-byte field;

a field indicating the number of data bytes transmitted;

and a checksum field.

5. In a mobile radio transceiver system having a digital logic control head, said control head including rotary and push button or toggle type switches for selecting transceiver operating conditions, a method for translating rotary switch movement in said control head into data for transmission over a serial data bus to a digital mobiel radio transceiver utilizing the same serial data message format employed for communicating push button or toggle switch position changes, said method including:

(1) sensing rotational movement of said control head rotary switch;

(2) determining the directional nature of said movement, if said sensing step (1) reveals that rotational movement of said rotary switch has occurred;

(3) transmitting a message of the same serial data message format employed for communicating push button or toggle switch position changes from said control head to said transceiver over said serial data bus whenever said sensing step (1) reveals that movement of said rotary switch has occurred, including transmitting a single bit within said message having a first logic level if said determining step (2) determines said switch position changed in a first direction and having a second logic level if said determining step (2) reveals said switch position changed in a second direction opposite said first direction.

6. In a digital mobile radio transceiver system utilizing a control head, said control head including rotary and push button or toggle type switches for selecting transceiver operational functions, a method for sensing and communicating the occurrence and direction of rotational displacement of a rotary switch position between said control head and a transceiver over a serial data bus using a single serial data messager format normally used for communicating push button or toggle switch positional change information, said method including:

(1) sensing the occurrence of a rotational displacement of said rotary switch;

(2) determining the direction of rotational displacement of said rotary switch;

(3) generating a multi-bit length data message specifying a rotary switch ID and including a single bit within said data message having a first logic level if said determining step reveals said rotary switch was displaced in a first rotational direction and having a second logic level if said determining step reveals said rotary switch was displaced in a second rotational direction opposite said first direction; and

(4) serially transmitting said data message to said transceiver via said serial data bus.

7. In a digital mobile radio transceiver system having a transceiver controller and a remote control head, an apparatus for sensing and communicating the occurrence and direction of rotational displacement of a rotary switch between said control head and said transceiver controller, comprising:

at least one continuously rotatable switch included with said control head for allowing rotational selection of transceiver operational function information;

a serial data bus coupled between said control head and said transceiver controller; and

digital control logic means within said control head for monitoring rotational displacement of said rotary switch and for generating and transmitting a serial data message including a sequence of bits to said transceiver controller via said serial data bus in response to detecting the occurrence of rotational displacement of said rotary switch;

wherein said serial data message includes a single predetermined bit having a first logic level if said rotational displacement occurs in a first direction and having a second logic level if said rotational displacement occurs in a second direction opposite said first direction.

8. An apparatus as in claim 7 wherein said serial data message includes a message-type field and an error checking field.

9. An apparatus as in claim 7 wherein said serial transceiver controller is a microprocessor.

10. An apparatus as in claim 9 wherein said digital control logic means is a microprocessor.

11. An apparatus as in claim 7 wherein said selectable operational function information includes group number information, system number information and audio volume information.