If RS = R?? S, it means that node S and node ?? S are in the same
region. The pseudo code of the algorithms is as follows:
/*Region-Growing(S)
Input: Node S
Output: Region R_S
*/
Initialize: R_S=I_S
Transmit R_S to all neighbor nodes
while (true)
R <- set of received region identifiers
r=min(R)
if(r
R_S=r
Transmit R_S to all neighbor nodes
end if
end while
return R_S
The algorithm initializes the region of a node S to contain only S, and
then pass this information to all the neighbor nodes within the radio range.
At each iteration, the region identifier set R is updated according to the information
from S??™s neighbor nodes. The region of node S, RS, is assigned to
be a minimum set (a set of distinct region identifiers having the same phenomena)
from the neighbor??™s information and its own old region information.
If its region set changes, node S sends the new information to its neighbors.
The loop terminates when all the nodes in the same region reach the same
identifer set.
Figure 14 shows an example [10] illustrating the algorithm, where a square
region is to be detected. We assume that the left-top most vertex in the square
has the smallest ID (region identifier) and the region growing set starts from
here. Initially, the region boundary R only contains the left-top most vertex.
After each iteration, the region boundary R moves one hop forward. This
phase is termed as the Growing Phase.
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