A network system comprising routers and a plurality of sub-networks, each of which connects apparatuses, wherein the plurality of sub-networks are identified by respective Net IDs, and are connected via the routers to form a tree structure. Each of the routers includes: first and second communication...http://www.google.com.hk/patents/US7539739?utm_source=gb-gplus-share專利 US7539739 - Self-configuring network system and routers for use therein
