MIL-STD-188-115

Abstract

The purpose of this document is to provide a standardized method of timing that will fully support Department of Defense (DoD) communications timing requirements during peace and war, as well as support new communications functions as the need arises. <br>The technical parameters promulgated by this document represent, in general, minimum interoperability and performance characteristics that may be exceeded in order to satisfy specific requirements. This document provides guidance required to achieve interoperability between existing and future communications facilities. In addition, emphasis has been placed on allowing maximum flexibility of system configurations to satisfy diverse user requirements. This document is not intended to be an engineering textbook or a reference handbook. However, this document does contain technical background information to explain how some of the standards were derived, why certain parameters were standardized, where these standards apply and how the standards are to be used. <br>This document does not apply to systems that do not have to interoperate with other systems. However, changing requirements and possible future needs and the benefits of standardization must be considered before making this determination. <br>This document is not a stand-alone, comprehensive, and engineering reference containing all the technical details required for the design of new equipment and facilities or the preparation of specifications. Consequently, design details such as size and weight limitations, cable assemblies and power supply requirements are not contained in this document. <br>NOTE 1: "Timing" is used here in a general sense which includes scheduling, regulating the rate and causing an action or event to occur at a desired instant relative to another action or event. Hence, synchronization is considered to be a special case of timing. <br>NOTE 2: "Time" is used in the sense of time-of-day (TOD). <br>NOTE 3: "Time interval" indicates the duration of a segment of time without reference to when the time interval begins and ends. Time interval may be given in seconds of time. <br>This document is to be used in the planning, design, development, procurement and installation of all new DoD digital communications systems and those existing digital communications systems undergoing major modifications or upgrade. This document does not necessarily apply to leased commercial facilities, but such facilities should be selected to be compatible with the requirements contained in this document. <br>It is not intended that existing systems be immediately converted to comply with the requirements of this standard. All design and development of equipment or systems started after the effective date of this document shall satisfy the requirements of this document. This document is in accordance with DoD Directive (DODD) 5160.51, Precise Time and Time Interval (PTTI) Standards and Calibration Facilities for Use by Department of Defense Components and Federal Standard 1002 (FED-STD-1002), Time and Frequency Reference Information in Telecommunications Systems. <br>The objective of this document with respect to timing and synchronization are: (a.) to insure a high degree of interoperation of long haul and tactical equipment, subsystems and systems consistent with military requirements; (b.) to provide a degree of system performance acceptable to a majority of users of communications systems; and (c.) to achieve interoperability, performance and compatibility in the most economical way. <br>The parameters and other requirements specified in this document are mandatory system standards (see appendix A) if the word "shall" is used in connection with the parameter value or requirement under consideration. Non-mandatory system parameters and design objectives are indicated as optional by the word "should" in connection with the parameter value or requirement under consideration. "Will" is used to express a declaration of purpose or intent. For a definition of the "system standards" and "design objective", see FED-STD-1037.