An underwater first contact method using JANUS

One motivation behind the JANUS underwater acoustic communication standard is to provide first contact functionality for new nodes joining a network. Some first contact procedures for the purpose have been proposed in literature, but not standardized. We propose an alternative procedure which was developed as part of the EDA-SALSA project, and has been successfully tested in simulations and in sea trials. The procedure includes address assignment mechanisms to get the last 5 bits of the address unique in a 2-hop neighbourhood, and also provides bit fields that can be used to negotiate which physical and network layer protocols to use.