Patent ID: 8102759

Claim:
A method for finding a backup node for a node in a sensor network, the method comprising the steps of: a. detecting, via the node itself, that the node is in a state of waiting to be backed up; and b. determining, via the node to be backed up, in response to detecting that the node is in the state of waiting to be backed up, an agent node from a plurality of nodes adjacent to the node to be backed up, wherein determining includes sending a request that the agent node find the backup node on behalf of the node to be backed up from a list of available backup nodes communicated directly in the request to the agent node from the node to be backed up, wherein (i) the agent node initially functions as a receiver node RN of the adjacent nodes, (ii) the receiver node estimates a quantity of electricity needed to perform the searching for a backup node according to the list of available backup nodes within the request, and (iii) if the quantity of electricity of the receiver node RN is larger than a sum quantity of (iii)(a) electricity needed to perform the searching for the backup node and (iii)(b) a particular threshold value, then (iv)(a) the receiver node RN sends a confirmation message to the node to be backed up to indicate that the receiver node RN becomes the agent node (AN), otherwise, (iv)(b) the receiver node RN sends a re-selecting message to the node to be backed up, wherein the re-selecting message directs the determining step, via the node to be backed up, to select another node among its adjacent nodes as its agent node, and wherein said determining step repeats the determining of another node as an agent node and the sending of the request that the another node find a backup node for the node to be backed up until an agent node is found.