STANDARD:

MIL-STD-188-110D

Overview

MIL-STD-188-110D describes the technical standards and design objectives for narrowband and wideband HF data modems. This version of the standard includes the wideband HF data modems spanning bandwidth from 3 to 48 kHz in 3 kHz steps.

Status

The fourth revision of the MIL-STD-188-110 “Military Standard Interoperability and Performance Standards for Data Modems” was released in December 2017.

Key Features

Autobaud capable Single Sideband (SSB) Wideband STM waveforms described in MIL-STD 188-110D and Appendix D of the MIL-STD 188-110C standard, specifies wideband HF Data Modem Waveforms for bandwidths from 3 kHz to 48 kHz in 3 kHz steps. In 24 kHz, the data rates range from 600 bps to 120 000 bps and in 48 kHz, the data rates range from 1200 bps to 240 000 bps.

Relevance

The 3 kHz bandwidth waveforms, as specified in MIL-STD 188-110C Appendix D and MIL-STD 188-110D, provides a better performance compared to the 75 bps to 2400 bps waveforms of the MS110A/MS110B specifications.
HF communication has generally been limited to narrower bandwidths and lower data rates compared to satellite communication. The availability of high data rate beyond line-of-sight (BLOS) communications without the use of satellites or radio-relay is important to provide satellite-like data services over HF.
The higher data rates supported by the waveforms are sufficient to support services not previously practical over HF radio, such as real-time video transmission.

Serial Tone Mode (STM) – Single Sideband

CAPABILITY BLOCKS				B/W [kHz]	WID
					0	1	2	3	4	5	6	7	8	9	10	11	12	13
					WALSH	BPSK	BPSK	BPSK	BPSK	BPSK	QPSK	8 PSK	16 QAM	32 QAM	64 QAM	64 QAM	256 QAM	QPSK
			B1	3	75	150	300	600	1 200	1 600	3 200	4 800	6 400	8 000	9 600	12 000	16 000	2 400
				6	150	300	600	1 200	2 400	3 200	6 400	9 600	12 800	16 000	19 200	24 000	32 000
				9	300	600	1 200	2 400	-	4 800	9 600	14 400	19 200	24 000	28 800	36 000	48 000
		BLOCK 2		12	300	600	1 200	2 400	4 800	6 400	12 800	19 200	25 600	32 000	38 400	48 000	64 000
				15	300	600	1 200	2 400	4 800	8 000	16 000	24 000	32 000	40 000	48 000	57 600	76 800
				18	600	1 200	2 400	4 800	-	-	19 200	28 800	38 400	48 000	57 600	72 000	90 000
	BLOCK 3			24	600	1 200	2 400	4 800	9 600	12 800	25 600	38 400	51 200	64 000	76 800	96 000	120 000
				30	600	1 200	2 400	4 800	9 600	16 000	32 000	48 000	64 000	80 000	96 000	120 000	160 000
				36	1 200	2 400	4 800	9 600	12 800	19 200	38 400	57 600	76 800	96 000	115 200	144 000	192 000
BLOCK 4				48	1 200	2 400	4 800	9 600	16 000	24 000	48 000	72 000	96 000	120 000	144 000	192 000	240 000

Four levels of WBHF capability are defined in Annex B:

WBHF Block 1 offers 3-kHz operation only, but with somewhat improved performance over STANAG 4539 3-kHz modems.

WBHF Block 2 offers 3, 6, 9, and 12-kHz waveforms, with constraint length 7 convolutional coding.

WBHF Block 3 includes waveforms up to 24 kHz, with both constraint lengths (7 and 9).

WBHF Block 4 includes waveforms up to 48 kHz, with both constraint lengths (7 and 9).