Protocol Stack

Are all these nodes using a single RF channel? That is, that channel is a shared medium, so that you need some sort of media access control protocol to arbitrate access to the RF? Or do you have independent channels from each node to the master (which would need some sort of multi-channel transceiver to listen to all the channels at once)?

For shared media, if you don't need high channel utilization, I'd recommend CSMA (assuming your receiver can supply the "busy" signal). If not, Aloha. That is, make sure all messages are acknowledge, and just transmit whenever they arrive. If you don't get an ack, retransmit.

For addressing (logical link control), I'd consider just using the Ethernet frame format. Possibly changing the size of the addresses, as 48 bits is a lot for this application, and there's no interaction with an Ethernet. But you'll need the minimum concepts of that protocol: source and destination addresses, frame length, protocol type, and CRC.

You might also consider RFC1549 (asynchronous HDLC) if you want a complete data link layer. PPP could also come in handy if your radio gear has special command sequences embedded in the data stream that you have to escape.

Are all these nodes using a single RF channel? That is, that channel is a shared medium, so that you need some sort of media access control protocol to arbitrate access to the RF? Or do you have independent channels from each node to the master (which would need some sort of multi-channel transceiver to listen to all the channels at once)?

For shared media, if you don't need high channel utilization, I'd recommend CSMA (assuming your receiver can supply the "busy" signal). If not, Aloha. That is, make sure all messages are acknowledge, and just transmit whenever they arrive. If you don't get an ack, retransmit.

For addressing (logical link control), I'd consider just using the Ethernet frame format. Possibly changing the size of the addresses, as 48 bits is a lot for this application, and there's no interaction with an Ethernet. But you'll need the minimum concepts of that protocol: source and destination addresses, frame length, protocol type, and CRC.

You might also consider RFC1549 (asynchronous HDLC) if you want a complete data link layer. PPP could also come in handy if your radio gear has special command sequences embedded in the data stream that you have to escape.