Patent ID: 7836155

Claim:
A method for assigning a global address to a node in an ad-hoc network including a plurality of nodes, the method comprising: generating, at the node, a global address using a local address of the node and a global prefix discriminating each of a plurality of networks; selecting, at the node, one of neighbor nodes as a relay node; instructing, at the node, the selected neighbor node to request, from an Internet gateway, assignment of a generated global address to the node, by using tunneling; and receiving, at the node, information, from the selected neighbor node, regarding whether the generated global address is assignable, wherein the local address of the node is allocated to the node according to result of searching whether the same local address is used in a neighbor table stored in a neighbor node, the neighbor table storing local addresses of neighbor nodes, wherein the information comprises a global address message indicating allowability of the generated global address, and the information is transmitted from the Internet gateway according to result of comparison of the global address with a pre-stored global address table in the Internet gateway, wherein the method further comprises: if the generated global address is currently assigned to another node, transmitting a message to the another node, wherein the transmitted message comprises an inquiry regarding whether the another node currently uses the assigned global address; if no reply is received in response to the transmitted message, reassigning the generated global address to the node; and if a reply is received in response to the transmitted message and the reply indicates that the another node does not currently use the assigned global address, reassigning the generated global address to the node.