OpenIPC Fiber-Optic Video Link for FPV Drones
Instead of broadcasting video over radio (like WFB-NG), an OpenIPC camera can be connected to the ground station with optical fiber. The drone unspools a thin single-mode strand and the camera's ordinary IP stream travels down it.
Such a link cannot be jammed by electronic warfare, is practically non-emitting (invisible to signal intelligence) and has zero packet loss — no FEC or retransmission needed. The price is a physical tether: the fiber can be cut, and the spool adds weight.
This is not WFB-NG
OpenIPC FPV uses Wi-Fi (WFB-NG) by default. The fiber variant is an alternative transport: it relies on the camera's native Ethernet output (SoCs like the SigmaStar SSC338Q have a built-in 10/100 Mbit Ethernet interface) and the Majestic RTSP/IP stream. The radio channel is simply swapped for glass. It is a community approach, not an out-of-the-box feature.
When it makes sense
- Heavy EW environment — where the radio link is jammed, fiber keeps working.
- Stealth required — fiber does not emit, so the drone is harder to detect and locate.
- Critical mission — a stable channel matters more than freedom of manoeuvre.
- Strong electromagnetic interference — glass is fully immune to EMI.
If you need flight freedom, many simultaneous drones, or simple logistics — stay on WFB-NG. Fiber is a niche tool.
How it works
The chain is simple: the camera outputs an IP stream over Ethernet, a media converter turns the electrical signal into light, it runs down a single fiber to the ground, and there everything happens in reverse. Tap any node in the diagram to see its role:
A single fiber carries both directions thanks to WDM (BiDi): video goes "down" on one wavelength (e.g. 1310 nm), control/telemetry go "up" on another (1550 nm). This is critical because the spool physically holds one strand.
Comparison with WFB-NG
| Parameter | Fiber optic | WFB-NG (Wi-Fi) |
|---|---|---|
| EW resistance | Absolute | Limited |
| Stealth | Non-emitting | Radio-visible |
| Packet loss | Zero (no FEC) | Handled by FEC |
| Range | Tens of km (one strand) | A few km |
| Channel latency | ~5 us/km (negligible) | Negligible |
| Freedom of manoeuvre | Limited by tether | Full |
| Payload weight | + fiber spool | + Wi-Fi card, antennas |
| Many drones at once | One strand each | Shared spectrum |
| Link-loss risk | Mechanical break = end | No physical tether |
Components
OpenIPC camera with Ethernet
You need a board where Ethernet works. The SigmaStar SSC338Q and SSC30KQ SoCs have a built-in 10/100 Mbit Ethernet MAC+PHY, and Majestic serves an RTSP stream over it. Many FPV-only (AIO) boards omit external Ethernet to save weight — check for an RJ45 or RMII/MII pads for an external PHY.
See SSC338Q + IMX415 and SSC30KQ.
Optical fiber
- Type: single-mode (SMF), ideally bend-insensitive G.657.A2/B3 — it tolerates a small bend radius on the spool.
- Form: bare 250 µm coated fiber — as light as possible.
- Weight: ≈ 0.05 g/m. So 10 km of fiber is ~0.5 kg of glass alone, plus the spool. This is the dominant payload contribution and the main limit on practical range.
Media converter + BiDi SFP
- Media converter for Fast Ethernet (100BASE-TX ↔ 100BASE-FX) with an SFP slot.
- BiDi SFP module (single-strand, WDM) — transmits and receives over one fiber on two wavelengths (Tx 1310 / Rx 1550 on one side, mirrored on the other). Typical reach: 20, 40, 80 or 120 km.
- Both ends must be a mirrored pair (if the airborne side is Tx1310/Rx1550, the ground side is Tx1550/Rx1310).
Spool and payout
The fiber is wound so it feeds off freely without tension during flight (payout). The key is never to violate the fiber's minimum bend radius (a few millimetres for G.657), or attenuation spikes and the fiber breaks.
Optical budget
For the link to come up, the transmit power must cover all the loss on the route:
- Fiber attenuation: ≈ 0.35 dB/km at 1310 nm, ≈ 0.20 dB/km at 1550 nm.
- Each splice: ~0.1 dB, each connector: ~0.3-0.5 dB.
- BiDi SFP budget (e.g. a 20 km module): typically 13-14 dB.
Example: 15 km × 0.35 dB/km ≈ 5.3 dB + 2 splices ≈ 0.2 dB. Total ~5.5 dB — comfortably within a 20 km module with margin. For longer routes pick an SFP with a larger budget (40/80 km) and keep ≥ 3 dB spare.
Latency
Light travels in glass at ≈ 200,000 km/s, i.e. ~5 µs per kilometre. Even 20 km is ~100 µs. Against the H.265 encode latency in Majestic and decode on the ground (tens of milliseconds), the fiber contribution is negligible. Glass-to-glass latency is set by the codec, not the route length.
Limitations and risks
- Mechanical break = instant link loss. There is no "graceful degradation" like radio.
- Spool weight limits range and flight time.
- Bend radius. Violating the minimum radius on the spool or in the mount is the main cause of signal loss.
- Fiber termination. Bare ends are usually fusion-spliced or field-connectorised — tools and skill required.
- No redundancy. One fiber is a single point of failure.
FAQ
Is this the same as WFB-NG?
How much latency does fiber add?
Why single-mode fiber and not multi-mode?
What is the maximum range of a fiber-optic video link?
Can a fiber-optic link be jammed by electronic warfare?
How much does the fiber weigh?
Next
- How to build the OpenIPC fiber-optic video link — step-by-step guide.
- WFB-NG — the standard radio option for comparison.