scope:

This document established 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.

These standards are mandatory within the Department of Defense (DOD) in the design, development and engineering of new communications facilities for both narrowband and wideband long-haul and tactical systems. In some cases, reference is made to other documents which provide standards for specific applications. It is not intended that existing systems be immediately converted to comply with the requirements of these standards. New systems, and those undergoing major modification or rehabilitation, shall conform to these standards subject to current procurement regulations. This document is applicable to the design and development of new data modems with standard data signaling rates up to and including 19200 bits per second (bps) used in long-haul and tactical communications systems. This document is not applicable to high frequency (HF) data modems used in the Tactical Digital Information Link (TADIL) A. The HF data modem standards for TADIL A are published in MIL-STD-188-203-1.

Requirements in this document, if applied as intended, shall ensure interoperability and performance of data modems having the same or similar functions. The variety of data modems shall be limited to that which is essential to effectively support the missions of the military forces. It is not intended that the standards contained in this document inhibit advances in communications technology, such advances are encouraged by including DOs which should be used if economically feasible. Additionally, such advances are facilitated by standardizing parameter values but not the technology that may be used to meet these parameter values. Mandatory equipment parameter values and requirements are specified by the use of the word "shall". Minimum performance requirements for the high frequency (HF) serial (single-tone) and parallel tone modem waveforms are specified in table XX and table B-XII, respectively. The specified values shown represent HF modem performance under ideal test conditions. To identify the minimum acceptable performance available to users, many factors, including operational test and evaluation, must be considered.

intended Use: