Two links with opposite requirements sharing one airframe, one antenna budget and one power budget. The command and control link must never drop and carries almost no data. The video downlink carries a great deal of data and may degrade gracefully. Designing them as one radio is the mistake; designing them as one system is the work.
An unmanned platform needs two things off the airframe and one thing onto it. Telemetry down, video down, and commands up — and those three have almost nothing in common except the antenna they share.
The command link is a safety function. A few kilobits per second, and it must survive when the video link cannot. It gets the robust modulation, the redundancy and the link margin, because losing it means losing the aircraft. The video link gets whatever capacity remains, and is designed to degrade rather than fail.
Everything else follows from weight and power. Every gram of radio is a gram not spent on battery or payload, and every watt of transmit power is flight time. That is why this is a system design problem rather than a module selection exercise — the right answer changes completely between a 2 kg inspection quadcopter and a fixed-wing platform flying a hundred kilometres.
| Parameter | Detail |
|---|---|
| Links | Downlink video and telemetry; uplink command and control, designed separately |
| Latency | Glass-to-glass budget stated end to end, not per-block |
| Video | H.264 and H.265 encode with adaptive bitrate against measured link quality |
| C2 resilience | Robust modulation, redundancy and margin sized so command survives video loss |
| Range | Line-of-sight and BVLOS configurations; mesh or relay where the link cannot close directly |
| Spectrum | Licensed and unlicensed options, with the band and power limits set per territory |
| Security | Link encryption and authenticated command, so a spoofed instruction is rejected |
| SWaP | Mass, volume and DC power stated as design constraints rather than outcomes |
| Ground segment | Ground station radio, antenna tracking where range requires it, and stream handoff |
| Platform | SDR-based, so waveform and band change in firmware rather than in hardware |
Maturity — silicon-proven, FPGA-validated or RTL stage — is confirmed at enquiry for the specific configuration you need, rather than claimed generically here.
Send the target node, the interface requirements and the integration context. If this is not the right fit, that will be said early rather than discovered at integration.
Because their requirements are opposite. Command carries a few kilobits and must never drop; video carries megabits and may degrade. Giving them one shared design compromises the link that matters most — losing command means losing the aircraft, while losing video means a poor picture.
The whole chain, stated glass to glass: sensor readout, encoder, packetisation, radio, ground receive, decode and display. Encoder and decoder buffering usually dominate, and a figure quoted for the radio alone tells an operator nothing about what they will experience.
Everything about the link budget and the failure case. Beyond visual line of sight the aircraft cannot be recovered by sight, so command resilience, defined lost-link behaviour and often a relay or mesh path become requirements rather than features — and the regulatory approval becomes part of the programme.
The encoder is driven by measured link quality rather than a fixed setting, so picture degrades progressively as margin falls instead of the stream stalling. How aggressively it adapts is tuned per deployment, because a survey flight and a live incident feed want different behaviour.
Every gram of radio is a gram not spent on battery or payload, and every watt of transmit power is flight time. The correct design for a 2 kg inspection quadcopter and a long-range fixed-wing platform are not the same design with different settings.
That is the reason for building on software-defined radio: waveform and band change in firmware rather than in hardware, which matters when a platform is sold into several territories with different spectrum allocations.
The same SDR lineage.
PRODUCTWhere terrestrial link cannot reach.
TECHNOLOGYCoding gain on a power-limited link.
SOLUTIONCoverage layers together.
PRODUCTInference on the airframe.
INDUSTRYLifecycles and obsolescence.
Tell us the specification, the constraint and the deadline. Programmes that cross silicon, radio, embedded and AI are where Faststream is strongest.