Content-Based Efficient Messages Transmission in WSNs

Algorithm 3

Get_logic_son_nodes (N_k, content_type).

1 N_k.current_physical_node = 1; // 1th physical son-node is being handled currently

2 push N_k into the stack: s;

3 while (s is not empty)

4  get the uppermost element of s: N_current;

5  i = N_current.current_physical_son;

6  get the ith physical son node of N_current: N_tmp;

7  if (N_tmp.type != content_type)

8   if (N_tmp has at least one son node)

9    N_tmp.current_physical_son = 1;

10    push N_tmp into s;

11   else

12    construct father-son relation: N_tmp is logical-son-node of N_k;

13    if (N_current has another physical node)

14     N_current.current_physical_node = i++;

15    else

16     pop N_current from s;

17 return;