The radio network for the Winter Train v3 is based on the wireless JeeNode platform. The JeeNode radio network is a simple package based communication system capable of both broadcast and point to point communication.
Due to limitations in the protocol used by the JeeNodes, the package header can only contain one radio “node” ID - either sender or receiver. In order to simplify implementation and debugging, all communication will be done as “broadcast” (which it anyway is). The package header will contain the sender ID. The first byte of the payload will specify the package type, which normally also will indicate the intended destination.
Based on this, any receiver can identify the sender and the content and hence determine, if the receiver should react on the received package.
The JeeNode protocol has a concept of node group. For this project, all nodes will belong to the same group: 101
Packet specfication for the radio network can be found here.