New Features / Improvements

• Add LinkLayerFeedback node that can batch CST (packet receive) and SST (noise) stats and transmit them to allow for feedback control. (!111 (merged))
  • Add LinkStatsFeedback message
  • Add unit test to CI
• Publish SST messages from modem sim (!111 (merged))
• Publish CST messages separate from ReceivedPacket messages in modem sim for received packets (!111 (merged))
• Improved CST parameter simulation (!111 (merged))
• Added documentation to SST message fields. (!111 (merged))
• Improved documentation of CST message fields. (!111 (merged))
• Add packet_rx_topic parameter to modem_sim_node to specify an alternate topic for ReceivedPacket messages. (!112 (merged))