Mobile computer terminal and system

• US 3,899,772 A
• Filed: 04/23/1973
• Issued: 08/12/1975
• Est. Priority Date: 04/23/1973
• Status: Expired due to Term

• Current Assignee: Alan B. Mead, David A. Malan, John L. Aker, John R. Alden
• Original Assignee: Alan B. Mead, David A. Malan, John L. Aker, John R. Alden
• Inventors: Aker, John L., Mead, Alan B., Malan, David A., Alden, John R.
• Primary Examiner(s): Curtis, Marshall M.
• Application Number:
  US05/353,509
• Time in Patent Office: 841 Days
• Field of Search: 340/152-154,324R,172.5 325/52,53,55 343/177,225-228
• US Class Current: 340/10.51
• CPC Class Codes: G06F 13/4063 Device-to-bus coupling
• CPC Class Codes: H04L 1/004 by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 27/2035 using a single or unspecified number of carriers
• CPC Class Codes: H04L 27/2277 using remodulation

Abstract

The disclosed two-way mobile digital communications system includes a plurality of remote terminal units, a programmable terminal controller operable to manipulate stored data from a plurality of local or remote computer files on command from any or all of the mobile terminal units in operational locations, and a network for communication between the central data processing station and the mobile terminal units. A high speed audio phase shift keyed transmission method has absolute phase referencing. Each of the remote terminals include a low-voltage solid state plasma screen which displays dot matrix characters. The buffer memory therein allows uninterrupted message composition and incoming message storage which the terminal controller insures the compatability of the remote terminal units with existing data bases and controls data transfer between the terminal units and for between the units and the computer data base.

Claims

1. In a mobile terminal computer system having a plurality of mobile terminal units, a base radio and a compuTer data base, the improvement comprising:

said mobile terminal unit including means for encoding, transmitting, receiving and decoding digital data means for communicating said digital data between said terminal unit, said base radio and said computer data base thereby facilitating terminal unit dispatching, unit status updating and computer information retrieval without voice communication, means for automatically transmitting an acknowledgement to said computer data base that digital data has been received by said mobile terminal unit, and means for transmitting an operator acknowledgement to said computer data base that said digital data is received by said termainal unit operator.

2. A mobile terminal computer system, said system comprising a plurality of mobile terminal units, each of said units including means for encoding, transmitting, receiving, and decoding digital data relating to its specific information, said unit further including means for visually displaying said data to be transmitted or received in alphanumeric characters, said displaying means having means for editing said data prior to said data being transmitted, a base radio, said radio operable to transmit and receive said data to and from said mobile terminal unit, a computer data base, a communications network means for effecting data communication between said base radio and said computer data base, said mobile terminal unit thereby obtaining said information from said computer data base by utilization of said transmitting and receiving means, said displaying means, said base radio and said communications network, and said system including means for automatically acknowledging the receipt of a message from either said data base to said terminal unit or from said terminal unit to said data base.

3. The combination as in claim 2 wherein said displaying means has a plurality of display lines, each of said lines being capable of displaying information data in alphanumeric characters and means for utilizing one of said display lines for a mode line to thereby indicate an operational state of said terminal unit.

4. The combination as in claim 3 wherein said displaying means has a display memory and a logic circuit having an output therefrom for controlling the displayed information on said mode line, means for detecting when the display is refreshing said mode line and means for switching the source of data from the display memory to said mode line logic circuit thereby permitting said mode line to indicate said operational state.

5. The combination as in claim 2 wherein said terminal unit transmitting means includes a means for automatically waiting for a radio channel to be free and to randomly space adjacent transmission thereby decreasing the probability for interference with other terminals in the same system.

6. The combination as in claim 5 including means for minimizing the probability of cochannel interference, said probability minimizing means indicating that the channel is clear for transmission, and means for insuring separation of terminal unit cochannel users.

7. The combination as in claim 6 including means for insuring that the channel is free for a return message acknowledgement to another unit or to said computer initiating the message.

8. The combination as in claim 2, wherein said terminal unit includes a means for transmitting function and status information from said terminal unit to said computer data base on command of the computer.

9. The combination as in claim 8 including means for transmitting terminal unit operational status from said terminal unit to said computer data base on command of said computer, said unit status including an indication of the terminal unit memory buffer condition.

10. The combination as in claim 2 including means for manually acknowledging a message received by said terminal unit, said manual acknowledgement thereby indicating the terminal unit operator'"'"''"'"'s comprehension of the received message.

11. The combination as in claim 2 wherein said terminal unit includes means for automatically acknowledging the receipt of a message from said computer data base under preselected conditions, said acknowledging means including a means for transmitting function and status information and the operational state of said terminal unit.

12. The combination as in claim 2 wherein said terminal unit includes a means for transmitting function and status information from said terminal unit to said computer data base upon command of said computer.

13. The combination as in claim 2 wherein said terminal unit has a display memory, and means for transmitting only meaningful data in said display memory without requiring that a special character be entered in said memory to indicate an end of message.

14. The combination as in claim 13 wherein said display has a means indicating the last data entered into the memory, and means for insuring that said meaningful data transmitting means transmits only information up to said last data entry.

15. The combination as in claim 14 wherein said terminal unit includes a means for transmitting function status information from said terminal unit to said computer data base upon command of said computer.

16. The combination as in claim 15 wherein said terminal unit includes a means for automatically acknowledging the receipt of a mesage from said computer data base under preselected conditions.

17. The combination as in claim 2 wherein said system includes an auxiliary device having the capability of recording information sent to said terminal unit and wherein said terminal unit includes a means for indicating to said auxiliary device that the terminal unit is in standby thereby permitting said auxiliary device to receive information intended for the terminal unit.

18. The combination as in claim 17 including means for clearing a memory associated with said terminal unit after said auxiliary device receives all information thereby allowing said terminal unit to receive additional information intended thereto.