ac2cz
commented
7 months ago Yes, good suggestions Steve. We have not fully implemented the Digipeter yet, but these bytes could be added. Unlike green cube it would be a cross band Digipeter. But similar otherwise.
Other commands, such as requesting a list of files, receive an OK ack packet and that could perhaps also contain a number. The equivalent of OK 59, haha.
From Stephen Belter: This occurred to me while working GreenCube: There is almost no feedback about the signal received at the satellite. If you hear your packet echoed back on the downlink, you made it! If you don’t hear your packet, good luck figuring out why.
My suggestion is to add a byte to the downstream packet to indicate two measurements:
Maybe 4 bits for received signal strength (RSSI or similar?) Maybe 4 bits for error, congestion, or collision?
Signal strength received at the satellite could be used as a feedback signal to the ground station to suggest too much power, too little power, or for feedback on polarity adjustment of the ground station transmit antenna for each packet received and echoed. For example, which is heard better at the satellite: RHCP or LHCP? This will likely change on each pass, if not during a pass.
Error, congestion, or collision might be a condition indication for the past 1-10 seconds (?) of traffic. The error detection and correction feedback (no error, corrected errors, uncorrected errors) gives an indication of how clean the received packet(s) were. Congestion might be a measure of time without received bytes. Collision could be a measure of multiple “start of message” seen but not completed or decoded.
The error, congestion, and collision indication could be useful for rudimentary flow control, helping tune the number of synchronization bytes at the start of a packet, and tuning the amount of transmitter on-time preceding or following a packet.