Full Report
Image: RNT Foundation What’s new: A Further Notice of Proposed Rulemaking by the Federal Communications Commission (FCC) about reallocating spectrum near that used by GPS. For background we are also including below in this post a National Telecommunications Information Agency (NTIA) letter to FCC on the same topic. Why it’s Important: FCC and NTIA are the two most important organizations for how spectrum is allocated in the U.S. Ideally, spectrum is allocated so users don’t interfere with each other. What else to know: FCC is an independent agency.* It is technically not part of the executive branch and is charged with managing spectrum in the best interest of the American public. Before it acts, the FCC publishes notices, seeks comment from the public, etc. to help ensure commissioners and staff have sufficient information to make decisions. NTIA represents the interests of the executive branch to the FCC. For example, the […]
Analysis Summary
# Regulation/Compliance: FCC Further Notice of Proposed Rulemaking (FNPRM) on 1675–1695 MHz and 2020–2025 MHz Bands
## Overview
This regulatory action involves a Further Notice of Proposed Rulemaking (FNPRM) by the FCC aimed at reallocating and auctioning prime mid-band spectrum. The proposal seeks to transition bands currently used by federal incumbents to shared or flexible-use terrestrial networks and Mobile Satellite Service (MSS) Direct-to-Device (D2D) operations. A critical compliance component involves ensuring these new uses do not cause harmful interference to the GPS L1 signal (1575.42 MHz) and other vital Position, Navigation, and Timing (PNT) services.
## Key Details
- **Issuing Authority:** Federal Communications Commission (FCC) with input from the National Telecommunications Information Agency (NTIA).
- **Effective Date:** N/A (Currently in public comment/rulemaking phase).
- **Jurisdiction:** United States; Radiocommunication services.
- **Status:** Proposed (FNPRM - WT Docket No. 26-284, GN Docket No. 26-281).
## Requirements
### Mandatory Requirements (Proposed)
1. **Interference Mitigation:** New MSS and D2D operators must ensure no harmful interference occurs to the GPS L1 signal at 1575.42 MHz.
2. **Spectrum Sharing:** Non-federal flexible wireless operations must adhere to shared-use protocols with incumbent federal operations in the 1675–1680 MHz band.
3. **Auction Compliance:** Participation in spectrum acquisition must follow FCC auction rules for the 1675–1695 MHz and 2020–2025 MHz bands.
### Recommended Practices
1. **KDB Adherence:** Organizations should monitor and follow the updated Knowledge Database (KDB) guidance requested by the NTIA regarding D2D user equipment.
2. **Resilient PNT Adoption:** Critical infrastructure providers are encouraged to implement "Resilient PNT" frameworks to mitigate risks of GPS signal degradation.
## Affected Organizations
- **Industries:** Telecommunications providers, Satellite Service operators (MSS), Aerospace, Defense, and Transportation (Maritime/Aviation).
- **Organization Size:** Large-scale telecommunications firms and satellite hardware manufacturers.
- **Geographic Scope:** United States (National spectrum allocation).
## Compliance Timeline
- **March 4, 2020:** NTIA formal letter to FCC requesting GPS protection measures.
- **October 9, 2026:** Publication of the FNPRM and current public discussion.
- **[Future Date]:** Close of FCC public comment period (TBD).
- **[Future Date]:** Final Rule issuance and Spectrum Auction commencement.
## Implementation Guidance
### Assessment Phase
- **Spectral Impact Analysis:** Assess how operations in the 1610-1660.5 MHz and 1675–1695 MHz bands might impact existing GPS-dependent hardware.
- **Dependency Mapping:** Identify all critical systems relying on the 1575.42 MHz (L1) signal.
### Implementation Phase
- **Hardware Calibration:** Ensure D2D user equipment meets filtering requirements to prevent out-of-band emissions.
- **Hybrid Infrastructure:** Deploy hybrid terrestrial/satellite systems that comply with the new "flexible-use" mandates.
### Validation Phase
- **Interference Testing:** Conduct field tests to ensure D2D operations do not degrade GPS reception in high-density areas.
- **FCC Certification:** Obtain equipment authorization through the FCC’s technical standards process.
## Technical Requirements
- **Frequency Guard Bands:** Adherence to specific megahertz separations to protect PNT signals.
- **Power Emission Limits:** Strict limits on the power levels of terrestrial transmitters in proximity to federal incumbent receivers.
- **Direct-to-Device (D2D) Standards:** Technical specifications for mobile devices communicating directly with satellites in MSS bands.
## Penalties & Enforcement
- **Fines:** Significant monetary forfeitures for unauthorized interference or operation outside of licensed parameters.
- **Other Consequences:** Potential loss of spectrum licenses and seizure of non-compliant hardware.
- **Enforcement:** Enforced by the FCC’s Enforcement Bureau via monitoring and public complaints.
## Related Standards
- **NIST PNT Profile:** Aligning spectrum use with the NIST Cybersecurity Framework for PNT services.
- **UK Resilient PNT Standard:** Alignment with emerging international standards for navigation resilience.
## Resources
- **Official Documentation:** [fcc[.]gov/ecfs/document/1030622877502/1]
- **FCC Fact Sheet:** [docs[.]fcc[.]gov/public/attachments/DOC-425709A1.pdf]
- **PNT Guidance:** [rntfnd[.]org/resilient-pnt-key-talking-points/]
## Practical Recommendations
- **Engage in Rulemaking:** Organizations should submit formal comments to WT Docket No. 26-284 to influence final technical specifications.
- **Audit PNT Resilience:** Move beyond reliance on a single GPS frequency (L1) by incorporating multi-band GNSS or eLoran alternatives.