El 23/09/16 a las 14:22, Edson W. R. Pereira escribió:
What would be required (from the point of view of paper work, logistics, approvals, etc.) to replace the current ISS packet radio TNC by a device that would implement some more efficient digital communications? The device could be a digipeater, but employing strong FEC and a more modern modulation and framing structure and perhaps some better scheme for channel access. Perhaps something similar to ngham.
https://github.com/skagmo/ngham
With FEC and higher speed, we could accommodate many more users on a single pass. A dedicated software application on the ground would implement the modem and process information -- separating different types of messages in different screens, providing a chat like mode for real-time communications, automatically forwarding APRS packets, etc.
Am I day dreaming?
Hi Edson,
You're not daydreaming that much. The BEESAT satellites have a digipeater using the Mobitex-NX protocol, which has some form of FEC.
Many other satellites on the Amateur bands transmit telemetry using strong FEC. For instance, AAUSAT-4 uses an r=1/2, k=7 convolutional code and (255,223) Reed-Solomon with CCSDS scrambling.
Support and experimentation for these and many other protocols is very easy today using SDR.
73,
Dani.