Patent ID: 8238355

Claim:
An Internet protocol (IP)-ubiquitous sensor network (USN), comprising: a plurality of sensor nodes having location information and performing a plurality of functions; and at least one router that the sensor nodes use for communication with an external network, each of the sensor nodes designating a nearest router with respect to each of the sensor nodes as a default router, and communicating with the external network through the router, wherein each of the sensor nodes broadcast a router request (RREQ) message at a fixed first frequency, and each router that receives the RREQ message stores location information of the corresponding sensor nodes in mapping tables, the RREQ message providing the locations of the corresponding sensor nodes, wherein each router respectively broadcasts router advertisement (RA) messages at a fixed second frequency for updating the location information stored in the mapping table, the RA messages providing a location of each corresponding router, wherein the sensor nodes that receive the RA messages are registered to a router that broadcasts an RA message received via the shortest distance, wherein the RREQ message includes distance information corresponding to the distance from a sensor node broadcasting the RREQ message to a router receiving the corresponding RREQ message, wherein the distance information included in the RREQ increases by a unit distance whenever the RREQ message passes through a sensor node from the sensor node broadcasting the RREQ message to the router receiving the corresponding RREQ message.