High integrity single transmission line communication system for critical aviation information

• US 5,170,401 A
• Filed: 01/08/1990
• Issued: 12/08/1992
• Est. Priority Date: 06/02/1988
• Status: Expired due to Term

• Current Assignee: Rockwell International Corporation
• Original Assignee: Rockwell International Corporation
• Inventors: Mohr, Glen E.
• Primary Examiner(s): Atkinson, Charles E.
• Application Number:
  US07/463,941
• Time in Patent Office: 1,065 Days
• Field of Search: 371/68.1, 371/68.2, 371/68.3, 371/37.1
• US Class Current: 714/820
• CPC Class Codes: G05D 1/0077 using redundant signals or controls
• CPC Class Codes: G06F 11/1497 Details of time redundant execution on a single processing unit
• CPC Class Codes: G06F 11/1625 in communications, e.g. transmission, interfaces
• CPC Class Codes: H03M 13/00 Coding, decoding or code conversion, for error detection or error correction; Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes error detection or error correction for analogue/digital, digital/analogue or code conversion H03M1/00 – H03M11/00; specially adapted for digital computers G06F11/08; for information storage based on relative movement between record carrier and transducer G11B, e.g. G11B20/18; for static stores G11C
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/242 by comparing a transmitted test signal with a locally generated replica
• CPC Class Codes: H04L 1/245 by using the properties of transmission codes

Abstract

A high integrity data communication system for use with critical aviation information on a single transmission line which also utilizes code generators at the transmitter and receiver ends together with means for comparing the outputs of the code generators thereby authenticating the information at the receiver end.

Claims

1. A data communication system, for use with critical aviation data, the system comprising:

a. a first signal source for outputting critical aviation data, which includes both address and real data components;

b. a second signal source for outputting critical aviation data which includes both address and real data components;

c. a comparitor means, coupled with said first signal source and said second signal source to compare the outputs of said first and said second signal sources to monitor the integrity of said outputs as being of extremely high integrity;

d. an address to label converter coupled with said first signal source for receiving said address component from said first signal source and thereby converting said address to a label output;

e. a CRC generator coupled with and receiving real data from said second signal source and receiving label output data from said address to label converter, said CRC generator outputting a CRC word;

f. a transmitter device coupled with said CRC generator for receiving said CRC word and for coupling with said second signal source for receiving said real data;

g. a single transmission line connecting with said transmitter for transmitting said label output, said real data and said CRC word;

h. a receiver for receiving said label output, said real data and said CRC word from said transmission line, said receiver outputting said CRC word said real data and an address request;

i. a second address to label converter for receiving said address request and for converting said address request to a second label output;

j. a second CRC generator for receiving said real data together with said second label output and thereby generating a second CRC word;

k. a comparitor for receiving said CRC word and said second CRC word and comparing said words for an identical nature and emitting CRC validity signal if said CRC word is identical with said second CRC word; and

l. a high integrity multi-channel line replaceable unit for receiving said real data and said CRC validity signals, whereby, the extremely high integrity real data from said first signal source and said second signal source are compared to maintain an extremely high integrity nature and said real data is used to generate a CRC word which is transmitted through the transmitter and the single transmission line to the receiver where the CRC word is compared with a newly generated second CRC word which is generated from the real data, the second CRC word is compared with the first CRC word to determine that the input into the second CRC generator is identical to the input to the first CRC generator, thereby authenticating the nature of the real data which is input into the line receiving unit.

2. A data communication system comprising:

a. a plurality of signal sources, for generating a plurality of data signals;

b. means for maintaining the integrity of said signals from said plurality of signal sources;

c. means for generating a first identifying code for the data signal;

d. a transmitter means coupled with said plurality of signal sources and said means for generating, said transmitter transmitting an output of said data signal and said first identifying code;

e. a single transmission line coupled with said transmitter for carrying said output;

f. a receiver coupled to said transmission line for receiving and outputting said output of said transmitter which includes said data signal and said first identifying code;

g. means for receiving from said receiver, said data signal and generating a second identifying code which would be identical to said first identifying code if said data signal had not been altered;

h. means for comparing said first identifying code and said second identifying code; and

i. means for outputting said data signal if said first identifying code is identical to said second identifying code.

3. A data communication system, of the type capable of detecting errors during generation and transmission of messages, said system comprising in operative combination;

a sending LRU having a first signal source therein, for outputting critical aviation data which includes both address and real data components, and further having a redundant second signal source therein for outputting critical aviation data which includes both address and real data components;

said first signal source and said second signal source outputting critical aviation data of an identical nature;

a receiving LRU, located at a remote location from said sending LRU;

a transmitter device coupled with said sending LRU;

a receiver coupled with said receiving LRU;

a single transmission line coupled with said transmitter device and with said receiver;

means for detecting errors occurring in the generation and transmission of critical data; and

whereby, a data communication system is accomplished between said sending LRU and said receiving LRU by said single transmission line.

4. A data communication system, of the type capable of detecting error occurrences during generation and transmission of both dynamic and static messages, said system comprising in operative combination;

a sending LRU having a first signal source therein, for outputting critical aviation data which includes both address and real data components, and further having a redundant second signal source therein for outputting critical aviation data which includes both address and real data components;

said first signal source and said second signal source outputting critical aviation data of an identical nature;

means for comparing said first signal source and said second signal source to confirm the identical nature of said first signal source and second signal source and thereby generating source validity bits;

means for separating the real data and the address from said first signal source;

means for converting said address to a label;

means for producing dithered bits in response to a sequence of identical addresses;

means for mixing said validity bits, said dither bits, said label and said real data to create a label, data, dither, validity bit stream;

means for generating a psuedo random code corresponding to the label, data, dither validity, bit stream;

a receiving LRU located at a remote location from said sending LRU;

a transmitter device coupled with said sending LRU for transmitting said psuedo random code and said real data;

a receiver coupled with said receiving LRU;

a transmission line coupled with said transmitter device and with said receiver; and

means for detecting errors occurring in the generation and transmission of critical data;

whereby an extremely high integrity data communication system is accomplished between said sending LRU and said receiving LRU by a single transmission line.