  The applications of Wireless Sensor Networks (WSN) contain a wide variety of
scenarios. In most of them, the network is composed of a significant number of
nodes deployed in an extensive area in which not all nodes are directly
connected. Then, the data exchange is supported by multihop communications.
Routing protocols are in charge of discovering and maintaining the routes in
the network. However, the correctness of a particular routing protocol mainly
depends on the capabilities of the nodes and on the application requirements.
This paper presents a dynamic discover routing method for communication between
sensor nodes and a base station in WSN. This method tolerates failures of
arbitrary individual nodes in the network (node failure) or a small part of the
network (area failure). Each node in the network does only local routing
preservation, needs to record only its neighbor nodes' information, and incurs
no extra routing overhead during failure free periods. It dynamically discovers
new routes when an intermediate node or a small part of the network in the path
from a sensor node to a base station fails. In our planned method, every node
decides its path based only on local information, such as its parent node and
neighbor nodes' routing information. So, it is possible to form a loop in the
routing path. We believe that the loop problem in sensor network routing is not
as serious as that in the Internet routing or traditional mobile ad-hoc
routing. We are trying to find all possible loops and eliminate the loops as
far as possible in WSN.
