Unjammable Communications for Air, Maritime Surface and Subsea Domains

Key Benefits

Battle-Proven Performance
- Battlefield-tested overseas against active electronic warfare systems
Unjammable & Undetectable
- Defeats electronic warfare attacks via wired connection
10,000x Data Transfer
- Data transfer rate over 10,000 times that of traditional copper systems
Extended Range
- Proven reliable performance at lengths in excess of 25 kilometers
National Defense Authorization Act (NDAA) Compliant
- 100% American made with carefully selected components
Lightweight & Compact
- Significantly lighter and smaller packs than market alternatives at equivalent range

Product Portfolio

Applications

Military & Defense Applications
Surveillance & Reconnaissance High-definition cameras and sensors on drones transmit secure, high-data-rate intelligence to operators in real time for immediate analysis and decision making
Combat Operations UASs provide live battlefield feeds, precise targeting information and control guided munitions with pinpoint accuracy in contested electronic warfare environments
Subsea Operations Command, control and real-time high bandwidth data distribution between host and linked platforms in harsh ocean environments
Special Operations Real-time ISR over hostile territory with secure communications that cannot be jammed, intercepted, or disrupted

Aerial Domain Solutions

Drone Fiber-Optic Tether (DFT) Packs
Resilient and secure long-haul communication link providing mission assurance to unmanned aerial systems (UAS)

Key Features

Lengths in excess of 25 km
Drone-agnostic packaging
Proprietary advanced winding method
No piloting limitations on turns or speed
Reduced latency over wireless

Download DFT Sell Sheet

Analog Fly-by-Fiber System (AFFS)
Crystal-clear first-person view video and UART command and control in a lightweight, small form-factor NDAA-compliant package

Key Features

Low power draw: 230 mW (drone unit)
Extreme temperature operation: -40°C to 85°C
Supports up to 80km fiber optic link
No controller modifications required
Clips directly into Radiomaster Pocket controller

Download AFFS Sell Sheet

Digital Fly-by-Fiber System (DFFS)
Low size, weight and power performance with less than 70-millisecond latency for HD video transmission

Subsea Domain Solutions

L3Harris Micro-Diameter Fiber-Optic Cable (MDF) spool

Micro-Diameter Fiber-Optic (MDF) Cable
Enabling linked real-time, reliable, high-bandwidth subsea data transfer over extended ranges

Key Features

High break strength
Tunable specific gravity
Low optical loss
Small bend radius
Temperature tolerant
High-speed payout survivable

Technical Specifications

Depth rating: >1,500 psi hydrostatic resiliency
Compact packaging: <20" length x 16" diameter for 40+ km
Fill factors: >75%
Operating temperature: -40°C to +70°C

Download MDF Sell Sheet

UxS Fiber-Optic Tether Systems

Still frame from Fiber-Optic Tether products video, flying drone with tether pack

Platform Integration & Mission Partnership

L3Harris transforms existing RF sUAS platforms into mission-ready systems with fiber-optic command and control

Our Capabilities

3D modeling and prototyping
Electrical integration
Software development
Field flight testing
Trained and certified drone pilots
NDAA-compliant products

Manufacturing Excellence

U.S.-Based Production at Scale

Capabilities

Expanded fleet of fiber pack winders (2025-2026)
Dedicated production facility with ability to ramp production
State-of-the-art test tank facility
Precision winding services

Quality Assurance

Quality Control testing on every manufactured cable run
Visual inspection of jacket
Pull-testing to validate break strength
Optical attenuation measurements at atmospheric and hydrostatic pressure (>1,500 psi)
Simulated real-world ocean and application-specific payout conditions

Proven Performance

Trusted by U.S. Military & Industry Partners

Navy Programs: MDF technology is a key component of the Improved Post-Launch Communications System (IPLCS) for the Navy's next-generation MK-48 Mod 8 torpedo
Industry Leadership: Multiple U.S. Navy and industry partners have selected L3Harris as their fiber optic tether provider for subsea applications, including autonomous underwater vehicle programs
Battlefield Validation: DFT systems are battlefield-tested overseas against active electronic warfare systems

Contact the Sales Team to schedule a demo

Unjammable Lifeline: L3Harris Fiber-Optic Tethers Keep Warfighters Connected

Battle-proven technology defeats electronic warfare threats across air, maritime surface and subsea domains.

L3Harris fiber-optic tethers provide unjammable communications for drones and subsea platforms, solving the critical vulnerability of radio frequency (RF) systems that adversaries routinely jam in contested environments.

When a special operations team needs real-time ISR over hostile territory, losing connectivity can mean mission failure. As adversaries deploy increasingly sophisticated electronic warfare threats, L3Harris Technologies delivers fiber-optic tether systems keeping warfighters connected when it matters most.

“

The threat is no longer theoretical – it is shaping the battlefield in real time. We see adversaries aggressively jamming, disrupting and hijacking RF-controlled unmanned aerial systems at scale, exposing a critical vulnerability in modern drone operations. Operational success now depends on resilient command-and-control architectures that can survive in the most contested electromagnetic environments on Earth.

”

- Dave Kornick, President, Intelligence and Cyber, L3Harris

Gallery

Analog Fly-by-Fiber System (AFFS) far-end close-up offset

Analog Fly-by-Fiber System (AFFS) far-end ramp mount feature

Digital Fly-by-Fiber System (DFFS) Family with controller forward-facing

Digital Fly-by-Fiber System (DFFS) far-end close view

Digital Fly-by-Fiber System (DFFS) far-end inputs/outputs

Digital Fly-by-Fiber System (DFFS) far-end ramp mount feature at angle

Digital Fly-by-Fiber System (DFFS) far-end ramp mount feature

Digital Fly-by-Fiber System (DFFS) far-end solo inputs/outputs – side A

Digital Fly-by-Fiber System (DFFS) far-end solo inputs/outputs – side B

Digital Fly-by-Fiber System (DFFS) far-end solo – top

Drone Fiber Optic Tether (DFT) Pack 2 km face

Drone Fiber Optic Tether (DFT) Pack 2 km side

Drone Fiber Optic Tether (DFT) Pack 5 km face

Drone Fiber Optic Tether (DFT) Pack 12 km face

Drone Fiber Optic Tether (DFT) Pack 20 km face

Drone Fiber Optic Tether (DFT) Pack 20 km side

Drone Fiber Optic Tether (DFT) Pack Line-up (left to right: 20, 12, 5, 2 km) Outside Shells with Digital Fly-by-Fiber System (DFFS) (far left) and Analog Fly-by-Fiber System (AFFS) (far right)

Drone Fiber Optic Tether (DFT) Pack Line-up (left to right: 20, 12, 5, 2 km)

Drone Fiber Optic Tether (DFT) Pack Line-up (left to right: 20, 12, 5, 2 km) Outside Shells

Analog Fly-by-Fiber System (AFFS) far-end close-up offset

Analog Fly-by-Fiber System (AFFS) far-end ramp mount feature

Digital Fly-by-Fiber System (DFFS) Family with controller forward-facing

Digital Fly-by-Fiber System (DFFS) far-end close view

Digital Fly-by-Fiber System (DFFS) far-end inputs/outputs

Digital Fly-by-Fiber System (DFFS) far-end ramp mount feature at angle

Digital Fly-by-Fiber System (DFFS) far-end ramp mount feature

Digital Fly-by-Fiber System (DFFS) far-end solo inputs/outputs – side A

Digital Fly-by-Fiber System (DFFS) far-end solo inputs/outputs – side B

Digital Fly-by-Fiber System (DFFS) far-end solo – top

Drone Fiber Optic Tether (DFT) Pack 2 km face

Drone Fiber Optic Tether (DFT) Pack 2 km side

Drone Fiber Optic Tether (DFT) Pack 5 km face

Drone Fiber Optic Tether (DFT) Pack 12 km face

Drone Fiber Optic Tether (DFT) Pack 20 km face

Drone Fiber Optic Tether (DFT) Pack 20 km side

Drone Fiber Optic Tether (DFT) Pack Line-up (left to right: 20, 12, 5, 2 km) Outside Shells with Digital Fly-by-Fiber System (DFFS) (far left) and Analog Fly-by-Fiber System (AFFS) (far right)

Drone Fiber Optic Tether (DFT) Pack Line-up (left to right: 20, 12, 5, 2 km)

Drone Fiber Optic Tether (DFT) Pack Line-up (left to right: 20, 12, 5, 2 km) outside shells

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