I'd like to present my project FlightZoomer, which offers telemetry over cellular IP at small cost:
- Onboard device: a smartphone (cost: less than for a dronecell unit)
- Ground device: a second smartphone
- Crack the NAT/firewall barrier: simply by using a relay server (which adds features b.t.w.)
- Reach the relay server via http://freedns.afraid.org/
- UDP based
- UDP hole punching trials did not bear fruit
- The communication is error tolerant in any aspects
- There is throuput throttleing as well as recovery from any failure. If e.g. the communication fails for more than 5 seconds, all the software communication layers are completely reinitialized from scratch
- While there is a mode which guarantees message delivery, most traffic works with a second fire&forget mode
- Communication using a proprietory, tailor made protocol
- The onboard smartphone talks with an APM/PixHawk using a bluetooth connection via a HC-06 device (+MAVLink)
What shall I say?
It works, latency is less than 100ms, the focus already has moved to additional features, which easily can be added on a smartphone based platform (use the rest of the available sensors/periphery like GPS, cameras, WiFi..., synthetic voice output, touchscreen)...
Impressions&look&feel of the system: