MIL-STD-188-110 Interoperability And Performance Standards For Data ModemsThis document establishes mandatory technical standards and design objectives \(DO\) that are necessary to ensure interoperability and to promote performance among data modulators-demodulators \(modems\) used in the voice frequency \(VF\) band of long-haul and tactical communications systems. This document also provides guidance to the designers of new data modems that incorporate characteristics not yet standardized by specifying the technical characteristics of data modems currently in the inventory. The purpose of this guidance is to ensure attainment of minimum acceptable performance and maximum interoperability between existing and future data modems with specified transmission channel conditions.

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MIL-STD-188-110C

LIST OF FIGURES

FIGURE 1. STANDARD INTERFACE BETWEEN DATA TERMINAL EQUIPMENT AND

DATA CIRCUIT-TERMINATING EQUIPMENT. .......................................................................12

FIGURE 2. SERIAL (SINGLE-TONE) WAVEFORM FUNCTIONAL BLOCK DIAGRAM .......20

FIGURE 3 AN EXAMPLE OF EQUIPMENT INTERFACE BLOCK DIAGRAM. ........................22

FIGURE 4 FEC ENCODER BLOCK DIAGRAM .............................................................................27

FIGURE 5. STATE CONSTELLATION DIAGRAM..........................................................................35

FIGURE 6. RANDOMIZING SHIFT REGISTER FUNCTIONAL DIAGRAM ...............................37

LIST OF TABLES

TABLE I. REFERENCE LIST FOR MODEM APPLICATIONS. ......................................................10

TABLE II. LOGIC AND SIGNAL SENSE FOR BINARY SIGNALS. ..............................................11

TABLE III. CHARACTERISTIC FREQUENCIES OF FSK DATA MODEMS FOR

SINGLE-CHANNEL RADIO EQUIPMENT. ................................................................................16

TABLE IV. ERROR CORRECTING CODING, FREQUENCY HOPPING OPERATION. ............26

TABLE V. ERROR-CORRECTING CODING, FIXED FREQUENCY OPERATION....................28

TABLE VI. INTERLEAVER MATRIX DIMENSIONS. .....................................................................29

TABLE VII. BITS-PER-CHANNEL SYMBOL. ...................................................................................30

TABLE VIII. MODIFIED-GRAY DECODING AT 2400 BPS AND 4800 BPS................................31

TABLE IX. MODIFIED-GRAY DECODING AT 75 BPS (FIXED FREQUENCY) AND

1200 BPS. ...........................................................................................................................................31

TABLE X. CHANNEL SYMBOL MAPPING FOR 75 BPS. ..............................................................33

TABLE XI. ASSIGNMENT OF DESIGNATION SYMBOLS D1 AND D2. ....................................34

TABLE XII. CONVERSION OF TWO BIT COUNT VALUE TO THREE BIT SYMBOL. ...........34

TABLE XIII. CHANNEL SYMBOL MAPPING FOR SYNC PREAMBLE. ....................................36

TABLE XIV. FREQUENCY-HOPPING OPERATION WAVEFORM CHARACTERISTICS. .....38

TABLE XV. FIXED-FREQUENCY OPERATION WAVEFORM CHARACTERISTICS. ............38

TABLE XVI. SERIAL (SINGLE-TONE) MODE MINIMUM PERFORMANCE............................39