Energy-Efficient Algorithm for Multicasting in Duty-Cycled Sensor Networks

. 2015 Dec 11;15(12):31224–31243. doi: 10.3390/s151229860

Algorithm 2 Approximate scheduling and constructing algorithm.

Input: A duty-cycled network G, a source node s and a set of destination nodes D;
Output: A multicast tree T and the set of transmitting schedules

M (T)

for the multicast tree T;

1:
Construct the auxiliary graph $G^{'}$ according to Definition 3;
2:
for all schedule node $u_{s}$ in $G^{'}$ do
3:
Call Algorithm 1 to determine the transmitting time slot for each schedule node;
4:
end for
5:
Call the Steiner tree algorithm to get a multicast tree $T_{a g}^{a p p}$ on $G^{'}$ ;
6:
Correct $T_{a g}^{a p p}$ to a valid multicast tree $T_{a g}^{c}$ on $G^{'}$ by using the three correction operations in Section 4.4;
7:
Map the valid multicast tree $T_{a g}^{c}$ into a feasible solution for MEMAP using the method in Theorem 4, including the multicast tree T and the set of transmitting schedule $M (T)$ ;
8:
return the multicast tree T and the set of transmitting schedule $M (T)$ ;