To imagine the impact of the DIFI standard, consider cable TV. Cable systems depend on coax cables and hardware-based set-top boxes to deliver content and switch between channels on a traditional TV, all under the control of the cable system. Adding a TV in another room requires a physical coax cable run and another set-top box. A smart TV, on the other hand, connects by Wi-Fi over a standard internet connection to access an unlimited selection of streaming services, with processing shifted from hardware to software running in the TV. Adding another TV requires only a login to the home network.

Truly interoperable digital IF replaces coax cables with standard IP networks, which can transport the digital signals any distance without loss.  Digitization makes possible the virtualization of hardware-based processes into software running on generic compute.  It enables use cases never imaginable before:

More flexible, redundant and resilient satcom gateways

Gateways may have dozens of antennas separated by hundreds of meters. Efficient design, when serving the antennas via coax, requires locating signal processing centrally and nearby.  With digital IF, processing can take place anywhere, including a remote cloud server.  It also allows new architectures with greater redundancy and resilience.  Standard terrestrial network connectivity, for example, enables the instant transfer of traffic from an overloaded gateway to one with idle capacity, regardless of distance.

Meeting the connectivity needs of Earth observation

This sector of the satellite industry meets its communication needs through global networks of interconnected ground stations, often managed by a ground-segment-as-a-service software platform.  A single ground station may need to accept downlinks from many different satellites requiring different modems – something nearly impossible with matrix switches and hardware modems but relatively simple when digitizing signals and spinning up software modems.

Bringing Moore’s Law to ground systems

Once analog traffic is converted to digital, it can be routed and processed in software instead of hardware devices.  The software, running on commodity servers, will vastly reduce capex needs while improving its performance with each new generation of silicon chips, instead of waiting for vendor upgrades.

Seamless integration with terrestrial telecom

Terrestrial networks rely on all-digital transport, virtualization, automation and orchestration. Satellite has been the telcos’ last resort for connectivity in part because of its manual and unique requirements. Digital IF is the first step in enabling digital automation in satellite and is crucial to lowering that barrier.

Simplifying earth station link budgeting

Teleports contend with the noise created by transporting IF/RF analog signals through coax cables or waveguides, as well as noise losses associated with every splitter, combiner, and switch in the system. To overcome this noise, engineers produce link budgets that are calculated and updated for every potential path that the service may take through the ground system. Switching to digital IF locks in the signal-to-noise level and maintains that level regardless of transport path, distance, splitting, combining or switching. This innovation on the ground will greatly simplify earth station planning and operations.

Eliminating coax challenges aboard aircraft

Coax cables require heavy shielding to prevent their L-band traffic from interfering with collision avoidance systems operating in the same frequency range.  These cables add weight and are inflexible and hard to install.  Switching to optical fiber carrying digital IF eliminates the problems.

Protecting soldiers in the battlespace

Soldiers avoid gathering near antennas because their signal attracts hostile fire.  The limited range of L-band IF, and the added losses it incurs, keep them too close to danger, but digital IF allows antennas to be controlled from any distance using standard IP network infrastructure and without incurring additional signal losses.

Enabling software-defined satellites

The new generation of satellites with steerable beams requires sophisticated software to manage their high volume and complexity.  Digital IF enables software-based ground infrastructure running on generic compute that can cost-effectively scale, while greatly simplifying the logistics of deploying and maintaining the system.