Algorithm 2. CH Election Algorithm (General Cluster)

Inputs: (1) nodes of cluster C

(2) size of cluster C: NO

(3) location of BS: (BS·x, BS·y)

Result: CH of Cluster C

1: calculate cluster center position Cen (XC, YC);

2: for i = 1 → NO

3:   calculate the objective function of node i, GiCH

4: end for

5: select the node with GCHmax as the CH of cluster C;