Switch to RF over IP: how DIFI is future-proofing satcom ground infrastructure for escalating data traffic
By Nima Razavi-Ghods, Head of System Engineering, Filtronic
Digital Intermediate Frequency Interoperability (DIFI) is key to the future of a lean, efficient and agile satellite communications ground segment. Filtronic is developing high-throughput, high-bandwidth devices to digitise and de-digitise signals – supporting the industry-wide shift to virtualised satcom infrastructure.
Digital Intermediate Frequency (DIF) or ‘RF over IP’ technology offers the opportunity for satellite data communications to scale up rapidly and cost-effectively, while preserving signal quality and improving resilience in the face of growing demand for data.
By encoding analogue radio frequency (RF) signals into standard Internet Protocol (IP) packets, data can be transported more reliably and securely, at scale and with minimal signal degradation even over long distances. In a digitised system, analogue RF signals are encapsulated as IP packets at source and transmitted over an Ethernet connection to the antenna station. There, signals are reconstructed back into RF upconverted to the required frequency, and amplified for transmission via the antenna to satellites.
Advantages of digital over analogue RF systems
Crucially, digitising signals at source and converting them back close to the antenna eliminates a whole swathe of analogue hardware, terminal building infrastructure and cabling currently used to process signals at the antenna station. This reduces capex and makes installation far simpler. There is no need for physical baseband modems, IF matrices or IF/RF cross-site cabling, and some elements of up and down conversion can also be eliminated. In practice, much of this terminal building infrastructure can be replaced by a single digitiser/de-digitiser located close to the antenna, alongside existing upconverters and downconverters.
By digitising signals at source and de-digitising them close to the antenna, signal quality can be maintained and losses in transmission significantly reduced. Analogue signals carried by coaxial cable are also more susceptible to interception, so moving to RF over IP using Ethernet cables also improves data security.
In a digitised system, more aspects of signal transmission can be managed by software, rather than hardware, making them easier to implement and upgrade. This enables traditional RF systems to be integrated into modern digital infrastructures, marking a major step forward in satcom technology.
Why is digitisation needed in satcom?
The continued exponential growth in data traffic means satellite communications must transition to DIFI to increase capacity, resilience and security. Fast-growing demand for data has seen the rapid expansion of LEO satellite constellations and high-throughput satellites (HTS) to deliver the necessary high-speed, high-capacity connectivity for advanced non-terrestrial networks of the future.
However, current analogue ground systems are struggling to keep pace and cannot be scaled quickly enough to meet future demand. These legacy hardware-heavy ground architectures are reaching their limits in terms of bandwidth, cost, capacity, scalability and flexibility. Transforming to digital infrastructure and transitioning towards higher frequencies solves these issues and enables satcom operators to rapidly and cost-effectively scale up their operations.
DIFI delivers capex and opex savings
The wholesale removal of hardware at satellite antenna sites translates to significantly lower capital expenditure when developing new ground-segment infrastructure, as well as reducing deployment times for these new assets.
Digitised infrastructure requires fewer hardware components, fewer cables and no terminal building, which equates to much lower operating and maintenance costs. Installation is much simpler and less costly too.
Existing antenna sites can be upgraded for DIFI operation, saving operating expenditure on maintaining legacy hardware and cabling, and eliminating building maintenance or rental costs. In fact, the operational savings made can easily fund the conversion of existing sites to DIFI.
High-throughput, high-bandwidth solution from Filtronic
As a leading innovator in satcom RF technology, Filtronic is developing an advanced digitiser/de-digitiser to open the door to DIFI for satellite ground operations. By combining digitising and de-digitising functions in one unit, our device provides a compact solution that can be deployed both at antenna sites to toggle signals between analogue and IP formats, and at data sources on the ground to encapsulate RF signals as IP packets prior to transmission.
What sets our new device apart is the combination of wide bandwidth and high channel count. Each of its six Tx/Rx channels supports bandwidths of up to 2.5 GHz on carriers of up to 7GHz. The hardware has also been designed with a modular architecture, allowing it to be tailored to specific frequency bands, and where required, to incorporate up/down conversion within the unit itself.
The combination of multi-channel flexibility, high throughput and modular versatility makes this device more capable than any other on the market – ready to support complex, high-bandwidth satcom architectures.
As a member of the DIFI consortium, Filtronic has been closely involved with the evolution of the standard, which is poised to be adopted by all vendors, operators and users, and will be the key to achieving industry-wide interoperability across all hardware in the satcom ground segment market.
Future-proofing products for satcom digitization
The shift to Digital IF is fast approaching. Satcom suppliers need to prepare now to future-proof their products for an increasingly digitised satcom environment. Every component, from solid-state power amplifiers and block upconverters to channelisers and digitisers will need to have built-in capability to interface with the DIFI ecosystem, enabling seamless interoperability across the wider satcom network.
Filtronic is well advanced on this journey. Our new digitiser/de-digitiser is on target for launch in 2026, providing unmatched levels of flexibility, throughput and bandwidth to meet the demands of an increasingly virtualised satellite communications environment.
To find out more about our DIFI technology, please contact Filtronic – [email protected]
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