Industry Input Requested on Updates to MIL-STD-188-164 and MIL-STD-188-165

FOR INFORMATION (RFI) REQUIREMENT Industry input on Changes to Military Standard (MIL-STD) MIL-STD-188-164: Interoperability of Super High Frequency (SHF) Satellite Communications Terminals and MIL-STD-188-165: Interoperability of Super High Frequency Satellite Communications Phase-Shift Keying (PSK) Modems. Defense Information Systems Agency (DISA) is seeking Industry feedback on proposed changes to MIL-STD-188-164 and MIL-STD-188-165. THIS IS A REQUEST FOR INFORMATION (RFI) NOTICE ONLY. THIS IS NOT A REQUEST FOR PROPOSALS. NO SOLICITIATION IS AVAILABLE AT THIS TIME. 1.0 Overview/Purpose The Department of Defense (DoD) is soliciting industry to provide comments on the published MIL-STD-188-164C/Change 2 and MIL-STD-188-165B/Change 2 and to prepare responses to satisfy unique DoD

requirements for future updates to the MIL-STDs and related Military Satellite Communications (MILSATCOM) systems. 2.0 Scope of Effort This RFI request is solely for gathering information and planning purposes. This RFI does not commit the U.S. Government to contract for any services or supplies whatsoever. All are advised that the U.S. Government will not pay for any information or administrative costs incurred in response to this RFI; all costs associated with responding to this RFI will be solely at the interested party’s expense. Not responding to this RFI does not preclude participation in any future solicitations or requests for proposals (RFPs). 3.0 Technical Characteristics The continuing evolution of terminal and modem capabilities presents several challenges to developing relevant and useful terminal and modem design

requirements. This is particularly true in the adoption of digital intermediate frequency (IF) (DIF) terminals and modems which may not include analog IF interfaces. In addition to traditional dedicated hardware form factors, DIF modems may also be provided as virtual platforms running on generic hardware which could be performing multiple functions. Requested Information The U.S Government is requesting input on changes to improve the clarity and/or consistency of the MIL-STD. Specific areas that are currently of interest are enumerated below, but input should not be limited to these areas. The Digital IF Interoperability (DIFI) Consortium is one of several working groups looking to define test and performance characteristics for DIF systems and components, as well as for virtualized platforms. How should MIL-STD-188-164 and MIL-STD-188-165 be updated to ensure DIF interoperability and performance? How should Digital IF modems and terminals be tested for purposes of WGS Certification? What new or updated

requirements in the MIL-STDs would aid in ensuring such tests are valid and useful? MIL-STD changes should not preclude the use of analog IF for terminals supporting such interfaces. Responses speaking to DIFI or similar working group efforts are welcome but not required. Gallium Nitride (GaN) amplifiers are known to have non-linear characteristics. How have these non-linearities manifested themselves in real world designs? How can these characteristics be managed in the context of a terminal where linear operations are required? How can the MIL-STD-188-164 be updated to maintain adequate performance when GaN amplifiers are used? How should MIL-STD-188-165 be updated to ensure Virtual Modem(s) software-to-platform interoperability and performance (whether platform is vendor provided or Government procured)? Are vendors interested in supplying both Virtual Modems and suitable hardware platforms to host them? How should MIL-STD-188-165 be updated to address minimum server or hardware platform system

requirements for Virtual Modems? What key hardware specifications would trigger a recertification of the host platform? What hardware specifications could be demonstrated as equivalent (non-risk) for purposes of certification? What is your approach for implementing transmission security (TRANSEC) with Virtual Modems? Response Guidelines Companies who wish to respond to this RFI should send responses via email no later than

17 July 2026. Companies submitting responses are encouraged but not required to attend the Industry Week meetings. Companies interested in participating in the Industry Week meetings are encouraged but not required to submit technical responses.