Algorithm 1 Cluster formation algorithm

For each $(i,j)$, initialize $t\leftarrow 0$, ${\rho }_{ij}^{\left(t\right)}\leftarrow 0$, and ${\alpha }_{ij}^{\left(t\right)}\leftarrow 0$. repeat  Update ${\alpha }_{ij}^{\left(t\right)}$ using (21) and send to neighbors.  Update ${\rho }_{ij}^{(t+1)}$ using (22) and send to neighbors.  Increment $t\leftarrow t+1$ until$|{\mathcal{U}}_i^{(t+1)}-{\mathcal{U}}_i^{\left(t\right)}|<\sigma$ for all i or $t>t_{max}$. Node i chooses ${\mathcal{I}}_i$ as its CH using (23).