The Nusantao Maritime Trading and Communication Network (NMTCN)is a trade and communication network that first appeared in the Asia-Pacific region during its Neolithic age. The concept was first suggested by Wilhelm Solheim, known for being the senior practitioner of archaeology in Southeast Asia today. The NMTCN attempts to explain the diffusion of cultural traits throughout the Asia-Pacific region, a pattern that does not seem to match the projections of cultural spread by simple migration theories. Today, it is one of the dominant theories for the early peopling of the Southeast Asian region.
Solheim suggests that if "elements of culture were spread by migrations, then the spread would have been primarily in one direction." He suggests that since the pattern of cultural diffusion in the Asia-Pacific region is spread in all directions, it is likely that the spread of cultural traits happened via some kind of trading network, rather than a series of migrations.
In Solheim's hypothesis, the Nusantao were the people who constituted this trading network. Solheim notes: