This paper is just put forward in such circumstances, combined with the national 863 specific subject "Distribute UAC Technology research in ocean".Consulted abundant domestic and foreign relevant references, according to physical characteristics of UWA channel and specials of UAN, the paper brought up new UAN protocol MACA-U (Multiple Access Collision Avoidance for Underwater Wireless) . Some OPNET network simulation results had brought out the feasibility and efficiency of MACA-U in theory.Subsequently, this paper used LabVIEW8.2 to realize the software of MACA-U, and then to meet up with the physical layer module to build a small UAN system called Underwater Acoustic Multi-node communications System (UAMS, Underwater Acoustic Multi-nodes communication System) including 4 nodes of the distributed communication. The pool experimental results show the efficiency of the MACA-U protocol worked under the two different topologies: multi-hopping and master-slave network topologies. The experiments also showed that the MACA-U protocol enhanced the anti-interference ability of UAMS and expressed a good performance in reliability and efficiency.
