The role of RF over Fibre in modern Defence applications
Author: Andy Haslam, Director of Business Development, PPM Systems
What is RF over Fibre (RFoF) and why is it utilised in Defence?
RFoF is a highly effective, low risk method of distributing data through fibre optic cable. This approach leverages the strengths of both RF and fibre optics. You can find out more about this in my recent blog ‘’Optimal data distribution over fibre – The Basics’.
It has been utilised in the commercial sector for many years and is consequently a low risk COTS offering. The difficulty lies in looking at these commercial applications and identifying where their suitability fits in the Defence sector, matching COTS application with CONOPS and CONEMP, and creating real-world use cases that Defence can embrace.
Defence has unique challenges to both gaining and retaining information advantage on the battlefield. The need for secure data distribution at ever higher frequencies and increased distances, coupled with the adoption of open architectures to facilitate CEMA / EMSO applications and Multi-Domain integration, is paramount.
Key benefits of RFoF for Defence applications
Much greater ranges and improved power
RFoF technology enables RF transmit solutions to have smaller form factor amplification at the point of transmission, which greatly improves the transmission range compared to traditional coax cabling that would require additional, large scale amplification in addition compensate for the cable losses. For RF receive solutions, the lossless nature has been proven to improve receive range by 5x.
Enhanced signal integrity and security
Optical fibres are inherently resistant to electromagnetic interference, which is critical in Defence environments where electronic warfare and physical intervention are prevalent. This resistance ensures the integrity and security of communications, making RFoF systems highly reliable for transmitting sensitive information, especially where TEMPEST compliance is required.
Optimising antenna placement
The ability to optimally place antennas is crucial for modern operations, as it enables the antennas to be remoted away from people and in positions that are best for transmitting / receiving RF signals. When coupled with fast optical switching, this enables operators to select the most appropriate antennas and to reduce the enemy’s ability to identify the locations of formations and operators.
Reduced weight and space requirements
Optical fibres are significantly lighter and more compact than traditional coaxial cables used for RF transmission. This reduction in weight and space is advantageous in Defence applications, where the space claim budget is tight, such as combat platforms, where the saved space can either be used by other battle winning capabilities, or to build in future capacity growth.
Improved bandwidth and data rates
The high bandwidth capacity of optical fibres supports the transmission of large volumes of raw data at high speeds. This capability is essential for modern Defence systems that rely on real-time data transfer, such as ISR, and C2 systems.
Open Architectures
RFoF solutions are built with open architectures, aligning to open standard suites such as the LCA and CMOSS, including their constituent standards like OpenCPI, MORA, JICD / AOCO, OpenVPX and GVA. This open architecture nature also helps ensure the RFoF solutions are hardware agnostic.
Allows performance to match capability
Modern electronic equipment, especially when CEMA / EMSO aligned, are highly capable systems. However, their performance is ‘hamstrung’ by using coax cabling to move RF signals, meaning that performance of the system when installed on a platform rarely matches the system capability. The benefits of RFoF allow the full potential and capability of CEMA equipment to be realised through lossless signal distribution and enhanced through dynamic optical routing when installed on a platform.
RFoF Defence Applications
RFoF facilitates the tactical and operational deployment of forces, improves information advantage and retention and plays an increasingly vital role in safeguarding national security and supporting Defence missions worldwide. Its ability to provide secure, high-bandwidth, and long-range signal transmission is transforming military operations, enabling more effective and resilient Defence capabilities and matching performance with capability. Some applications of this mission-changing technology are:
- Flexible CEMA, C4 and ISR solutions
- RFoF Vehicle Integration Kits (VIK)
- Remote antenna solutions
- RF filters, switching, signal conditioning and distribution components with high power
- Software defined/configurable radio platforms
- RF signal analysis and simulation equipment
- C-IED / C-UAS ECM systems
Acronyms
COTS: Commercial off the shelf
CONOP: Concept of Operations
CONEMP: Concept of employment
CEMA: Cyber and Electromagnetic Activities
EMSO: Electro-Magnetic Spectrum Operations
ESM: Electro-Magnetic Spectrum
C4ISR: Command, Control, Communications, Computers, Intelligence, Surveillance, Reconnaissance
C-IED: Counter Improvised Explosive Device
C-UAS: Counter Un-manned aircraft system
ECM: Electronic Counter Measures