Area of Interest (AOI): Expeditionary Very Low Frequency (ExVLF) Transmitter SystemAmendment 0001PAO Release Number: NAVWAR HQCA-2026-A-071Notice ID: N0003926RB004Notice to Industry: This is an AOI issued under Naval Information Warfare Systems Command (NAVWAR) Commercial Solutions Opening (CSO) number N0003925S0001. This AOI solicits white papers/solution briefs (Phase 1 of the CSO) from industry. To the extent that any implementing regulations have not been updated to reflect statutory changes, the terms of the statute shall govern. Responses Due: 18-AUG-2026 at 2:00 PM PDT*Questions Due: 28-JUL-2026 at 2:00 PM PDT.*Answers to questions included below.The Government may not address all questions received. Questions and Answers will be posted on the NAVWAR CSO Website: https://www.navwar.navy.mil/Work-With-Us/Open-CSO-Calls/Contact information for questions and technical/submission issues: ian.m.robinson14.civ@us.navy.milBackground:The Expeditionary Very Low Frequency (ExVLF) communications system is a modular, relocatable communications suite supported by an aerostat-lofted tethered antenna that enables 24/7 VLF radio wave data broadcasts over distance to maritime mobile and shore-based receive nodes.Problem StatementThe US Navy seeks solutions for an Expeditionary Very Low Frequency (ExVLF) transmitter system. The Navy requires a high-reliability solution that supports 24-hour per day, 7-day per week (24/7) data broadcast operations. As a result of this AOI, it is anticipated that initial efforts will focus on a prototype delivery phase, with potential options for follow-on production units to satisfy long-term operational inventory objectives. The system must be designed for deployment in rugged, multi-environment locations and integrate with Government-Furnished Equipment (GFE).Primary Solution Attributes:? High-Power Performance and Tuning: A containerized VLF transmitter system, consisting of a power amplification subsystem and a dynamic and automatic tuning element subsystem, designed to generate and radiate RF power by integrating with and automatically tuning to the specific complex impedance characteristics of a government-furnished Wireless Communications Aerostat (WCA) tethered antenna.? Integrated Transmitter System: The entire transmitter system must be housed within a no greater than 20-foot ISO general-purpose freight container to ensure it is transportable, deployable, and relocatable in diverse environments. The assembly must be hardened for deployment in rugged environments and include all necessary subsystems for operation.? Modulator and Signal Generation: An integrated subsystem to generate the required VLF waveforms. All signal characteristics, including modulation formats, reference frequency accuracy, and timing, must be sufficient to meet the top-level requirements of the ExVLF data broadcast mission.? Control and Monitoring System: A unified control system for local and remote operation of the transmitter. It should provide status monitoring, fault detection, and the ability to interface with the overarching ExVLF network command and control structure.? Mast and Feedline System: A deployable mast and feedline to provide the RF connection from the transmitter to the WCA mooring station.? Ground Plane System: A deployable ground plane system to ensure efficient RF radiation from the antenna system.? Interoperability: The system must be made interoperable with GFE, including a prepared flight pad, the WCA system, communications equipment, site logistics vehicles, and site power.Desired Solution Attributes:? Mobile Power Delivery System (MPDS): The MPDS provides the necessary operational power to the WCA (excluding transmission RF power). The Government seeks a full spectrum of solutions, both with and without an integrated MPDS. Additionally, we welcome proposals for a separately priced MPDS option. The MPDS shall provide power based on the aerostat vendors requirements; it shall function with or without RF power being transmitted; it shall fit within the primary transmitter equipment International Organization for Standardization (ISO) container; and it shall draw its prime power from the primary transmitter power distribution unit (PDU) or an external PDU. ? Next-Generation Transmitter Technology: Implement modern, efficient, and agile transmitter designs that offer greater efficiency, reliability, flexibility, or ease of control than legacy transmitters.? Smarter Station Control and Automation: Artificial Intelligence and machine learning for predictive maintenance, automatic tuning, or dynamic adjustments based on environmental conditions.? Hardening and Resiliency: While the VLF transmitter must be resilient to natural events (e.g., lightning, severe thunderstorms, and earthquakes), new materials, technologies and methodologies could enhance robustness, prevent system damage, and reduce the impact on transmitter operations by enabling it to continue broadcasting throughout an event. Measures must also be taken to guard against manmade events (such as cyberattacks or operator error) through hardening and other protective features. ? Enhanced Maintainability: Modern maintenance tools such as AI/ML based predictive maintenance, Built-In Test (BIT), self-healing software, autonomous component failover, and hot-swap components can dramatically reduce the maintenance burden on system maintainers, minimize site downtime, and optimize utilization of spare parts. Steps should be taken to reduce the maintenance burden on transmitter maintainers.? Technical Data and Supportability: Successful long-term sustainment necessitates availability and access to detailed system technical manuals, drawings and parts lists, training, technical support, and spare parts for the life of the system. Transmitter sustainment and supportability should be considered. Immersive training tools such as augmented reality and digital twins can be used to enhance the training experience operators and maintainers receive, enhancing their ability to sustain the system. Additional Notes:? Cybersecurity: Cybersecurity and Information Assurance best practices must be implemented and strictly adhered to. Measures must also be taken to protect the supply chain from malicious and/or counterfeit software and hardware components to ensure safe, secure, and reliable operation of the system.? Security: Companies must have experience deploying on classified networks and ability to perform work in these environments and cleared personnel who can work up to TS/SCI. It is encouraged that submissions highlight experience with controlled environments, such as deployments in classified data/environments (https://public.cyber.mil/dccs/). Preference will be given to companies whose solutions can be deployed to meet DoD security standards, or have an equivalent Authority to Operate (ATO). ? Demonstration: Companies are expected to describe how their solution will meet Government requirements via a presentation in an unclassified environment as part of Phase 2 of the CSO AOI. o Technical Viability: Explaining exactly how your commercial technology solves the governments specific mission problem.o Rough Order of Magnitude (ROM): Providing a high-level, preliminary cost estimate and commercial pricing model.o Project Schedule: Presenting a notional timeline and key milestones for the prototyping phase.o Data Rights and IP: Asserting your companys positions on intellectual property, data rights, and software licensing.o Live QandA / Demonstration: Evaluators will ask questions to your technical team on potential bottlenecks. The Government may initiate additional communications after the Phase 2 Pitch Session has ended.? Teaming: The Government may seek to team companies with complementary solutions under the umbrella of this AOI; or in coupling of other AOIs issued within NAVWAR. Selected vendors may be requested to engage in partnerships with other vendors to achieve Government objectives.? Prototype Projects: The Government is interested in mature commercial technologies, as well as prototype efforts. A Prototype Project is defined at 10 USC 4022(e)(5) as a project that addresses: (A) a proof of concept, model, or process, including a business process; (B) reverse engineering to address obsolescence; (C) a pilot or novel application of commercial technologies for defense purposes; (D) agile development activity; (E) the creation, design, development, or demonstration of operational utility; or (F) any combination of subparagraphs (A) through (E).Awarding Instrument:This solicitation will be awarded in accordance with the NAVWAR CSO process detailed within N00039-25-S-0001 (NAVWAR CSO), posted to SAM.gov on 4 JUN 2025. This document can be found at: https://sam.gov/opp/a606b587755240e1a0b4f7d1e8d557bc/viewPlease refer to NAVWAR CSO for additional information regarding the three-phase process:Phase 1: Solution BriefsPhase 2: Pitch SessionPhase 3: ProposalVendors are reminded that in order to utilize an Other Transaction (OT) agreement the requirements of 10 USC 4022(d) must be satisfied: (A) There is at least one nontraditional defense contractor or nonprofit research institution participating to a significant extent in the prototype project.(B) All significant participants in the transaction other than the Federal Government are small businesses (including small businesses participating in a program described under section 9 of the Small Business Act (15 U.S.C. 638)) or nontraditional defense contractors.(C) At least one third of the total cost of the prototype project is to be paid out of funds provided by sources other than the Federal Government.(D) The senior procurement executive for the agency determines in writing that exceptional circumstances justify the use of a transaction that provides for innovative business arrangements or structures that would not be feasible or appropriate under a contract, or would provide an opportunity to expand the defense supply base in a manner that would not be practical or feasible under a contract.Any resulting agreement from this solicitation will include language requiring your company to confirm compliance with Section 889 of the John S. McCain National Defense Authorization Act for Fiscal Year 2019 (Pub. L. 115-232). If you are unable to confirm compliance with the referenced law, the Government will not be able to enter into an agreement with your company.Potential Follow-On Contract or AgreementsCompanies are advised that any Other Transaction (OT) agreement for Prototype awarded in response to this solicitation may result in the direct award of a follow-on production contract or agreement without the use of further competitive procedures. The follow-on production contract or agreement will be available for use by one or more organizations within the Department of Defense. As a result, the magnitude of the follow-on production contract or agreement could be significantly larger than that of the Prototype OT agreement. All Prototype OT agreements will include the following statement relative to the potential for follow-on production: In accordance with 10 U.S.C. � 4022(f), and upon a determination that the prototype project for this transaction has successfully been completed, this competitively awarded Prototype OT agreement may result in the award of a follow-on production contract or transaction without the use of competitive procedures.Response InstructionsPer the N0003925S0001 NAVWAR CSO announcement, vendors interested in responding to this AOI are invited to submit Phase 1 Solution Briefs. Solution Briefs shall not exceed five (5) written pages using 12-point font or, alternatively, Solution Briefs may take the form of briefing slides which shall not exceed fifteen (15). Title Page (does not count against page limit)Company Name, Title, Date, Point of Contact Name, E-Mail Address, Phone, Address, CAGE (if available). Specifically identify the AOI for which the Solution Brief is submitted.Executive Summary (one page limit, included in five (5) page limit)Provide an executive summary of the technology.Technology ConceptDescribe the unique aspects of your technology and the proposed work as it relates to the AOI. Identify whether the effort includes the pilot or demonstration of existing commercial technology (identified as commercially ready and viable technology), or the development of technology for potential defense application. If development or adaptation is proposed, identify a suggested path to mature the technology. Identify aspects which may be considered proprietary.Company ViabilityProvide a brief overview of the Company. Provide a summary of current fundraising to date or a summary of the top line (gross sales/revenues). Provide a summary of product commercialization and go-to-market strategy. Self-Identify as Traditional or Non-Traditional Defense Contractor as defined in 10 USC 3014. Identify planned teaming arrangements, joint ventures, and/or associate contractor agreements (ACAs).Recommended Award TypeCompanies shall recommend an award type to be considered for the effort (FAR-based Procurement Contract or OTA). Should the Company be asked to submit a Proposal in Phase 3, the Government and Company will further negotiate the best type of award for the effort.Markings in accordance with N0003925S001 2.3.1.6All solution briefs containing data that is not to be disclosed to the public for any purpose, or used by the Government except for evaluation purposes, shall include the following statement on the cover page of the submission:This Solution Brief includes data that shall not be disclosed outside the Government, except to non-Government personnel for evaluation purposes, and shall not be duplicated, used, or disclosed -- in whole or in part -- for any purpose other than to evaluate this submission. If, however, an agreement/contract is awarded to this Company as a result of -- or in connection with ? the submission of this data, the Government shall have the right to duplicate, use, or disclose the data to the extent agreed upon by both parties in the resulting agreement. This restriction does not limit the Governments right to use the information contained in this data if it is obtained from another source without restriction. The data subject to this restriction are contained in sheets [insert numbers or other identification of sheets].Each restricted data sheet should be marked as follows: Use or disclosure of data contained on this sheet is subject to the restriction on the title page of this proposal.Submission InstructionsVendors interested in submitting a response to this AOI must submit their solution brief via the Procurement Integrated Enterprise Environment (PIEE) Solicitation module link provided in this posting. The Government will not accept emailed submissions. If you have any questions regarding submission you may contact the Government point of contact identified in the SAM.gov posting/notice. The Government will not pay respondents for the costs associated with the submission of white paper/solution briefs. Questions and AnswersPAO Release Number: NAVWAR HQCA-2026-A-0771: Will NAVWAR consider solution briefs addressing a defined subsystem or portion of the ExVLF system rather than a complete end-to-end transmitter solution?A Phase 1 Solution Brief that focuses on your specific capabilities is encouraged, as the Government is interested in the full breadth of industry solutions. In your submission, please present your capabilities and state your interest in partnering with other vendors. The Government is open to teaming complementary solutions in the interest of maximum flexibility, subject matter expertise and experience, reduced development/lead time, and cost savings to arrive at an end-to-end transmitter solution. The Government is unlikely to award a partial solution in the absence of teaming.2. Is an active facility clearance required at the Phase 1 solution brief stage, or may classified portions of the effort be performed later under a cleared prime contractor or teaming partner?The Phase 1 solution brief will not require a facility clearance and can be submitted electronically for consideration. If a prime vendor with an active security clearance has identified a teaming partner, the Government will accept prime vendor pitches on behalf of the teaming partner with written agreements. However, classified data cannot be shared with an uncleared teamed partner. Phase 1 and Phase 2 submissions shall be unclassified.3. Can we assume that we will get FCC support / sponsorship for experimental VLF license for testing purposes? The Vendor shall provide technical data describing transmitter attributes for review for compliance ahead of any Government submission of a DD1494 - Application for Equipment Frequency Allocation.4: The solicitation states a VLF transmitter. Are receive capabilities not required for this implementation?This AOI solicits only VLF transmission.5. What are the objective and threshold timelines for site emplacement (container offload to on-air broadcast) and for displacement, and with what crew size and skill mix?The Government expects to share information on set-up times in future phases and values solutions that do not rely on heavy equipment, such as cranes or forklifts to operate. 6. What environmental conditions and standards does the system need to meet? How frequently is a system expected to relocate over its service life, and what is the expected service life of the system?The system should be efficiently relocatable for planned/unplanned pick-up and drop-off cycles and be sturdy enough to move without requiring refurbishment or recalibration. The containerized system must meet transportation standards for over-the-road, air or marine travel while withstanding environmental factors including shock, vibration, temperature extremes, humidity, blowing sand/dust, altitude.7. The AOI states that proposed solutions must integrate with Government Furnished Equipment listed in the description. Is it a hard and fast requirement to integrate with everything listed, or can offerors propose innovative solutions that make some of the GFE obsolete?The Government is open to proposal of novel solutions, however the GFE and non-developmental items listed are the tested solutions of record at this time. Phase 1 submissions that offer unique and innovative solutions improving or making NDI/GFE obsolete are encouraged to understand there are GFE sub-systems that have specific attributes to support other equipment and vendors in the capability, and as such, changes are evaluated on impacts to those other sub-system components.8. What RF output power is required? What harmonic and spurious emission limits apply?We encourage you to submit a Phase 1 Solution Brief that focuses on your specific capabilities. The government is interested in the full breadth of industry solutions for mobile transmitters.9. Must the mast, feedline, ground plane system, and (if proposed) the MPDS all stow within the single 20-foot ISO container for transport, or does the 20-foot limit apply to the operating transmitter equipment only? Is a second container or trailer for support and installation items permissible?Government requires the solution to fit within the confines of 20-foot ISO container(s). Preference is for one container. The Government is open to solutions that require more than one 20-foot ISO container.10: What cybersecurity, network classification and Authority to Operate (ATO) requirements apply?Detailed statements on cybersecurity efforts are expected from companies during Phase 3 of the AOI. The AOI states Cybersecurity and Information Assurance (IA) best practices must be implemented and strictly adhered to. Measures must also be taken to protect the supply chain from malicious and/or counterfeit software and hardware components to ensure safe, secure, and reliable operation of the system. 11: How many prototype systems are expected under this AOI? Subject to available funding, the Government anticipates delivery of multiple prototype units.12: How many systems are expected to be needed after the delivery of a successful prototype? What is the expected delivery schedule?A successful prototype is expected to proceed to follow-on production; the Government expects to share these details in phase 2. Delivery schedule will be negotiated at Phase 3.13: The AOI mentions a Government-furnished Wireless Communications Aerostat (WCA) tethered antenna. Can we assume that the WCA and the antenna is provided by the Navy? Where will the testing or demonstration take place? The WCA is considered non-developmental. Iterative testing approaches are acceptable; government-witnessed high power ground testing at contractor location is expected to proceed with a contractor-acquired VLF dummy load to verify agreed-on performance. A government-integrated flight demonstration at a government-arranged site CONUS between the transmitter and government-owned non-developmental items would follow to validate needed performance.14: What is the expected distance between the transmitter ISO container and the Wireless Communications Aerostat (WCA) mooring station connection point?The system must support physical separation between the transmitter container and the mooring station; detailed interface and feedline lengths will be provided in the follow-on Interface Control Document (ICD).15: The Government received vendor questions regarding GFE and non-developmental item interface and dependent system questions, including connection details from the ExVLF C2 system and the transmitter, the modulator, the mobile power delivery system operational power requirements and isolation, impedance and other electrical properties of the WCA antenna tether, VLF frequency coverage, site power availability, and other detailed requirements.WCA variants have different requirements, capabilities, and tether electrical properties. Information on detailed specifications for this, and all other GFE and non-developmental item interfaces will be provided in an interface control document in a follow-on phase.16: What are the operating altitudes of the aerostat? The Government expects to share these details in future phases.
