Algorithm 2: Pseudocode to select cluster heads in the HSFZ.

Input:$X=X_1,X_2,\dots ,X_n$: set of LoRa Devices (LDs) Input:$A^{\left(i\right)}$: LoRa Device metric attributes Input: N: number of LoRa Devices Input:$\kappa$: optimal number of CHs Output: Clusters of all LDs in HSFZ, CH allocation 1:Network initialization 2:All $C^{\left(i\right)}=b_0$ 3:for$i\leftarrow 1$: N do 4:    Calculate the $E_{re\_N_i}\left(t\right),L^{\left(i\right)},D_{ratio}(n_i,N_i)$ 5:    if $L^{\left(i\right)}\ge L_{th}$ && $E_{re\_N_i}\left(t\right)\ge E_{th}$ then 6:        Add LD(i) to CH candidate set 7:    else 8:        Add LD(i) to cluster member (CM) 9:    end if 10:end for 11:for$AllLDs\in CHcandidateset$do 12:    Calculate the $P(C=b_1|A^{\left(i\right)})$ 13:    if $P(C=b_1|A^{\left(i\right)})=\max \left\{P\right(C=b_1|A^{\left(i\right)}$)} then 14:        $C^{\left(i\right)}=\left\{b_1\right\}$// LD(i) is set as a CH 15:    else 16:        $C^{\left(i\right)}=\left\{b_0\right\}$ // LD(i) is set as a CM 17:    end if 18:end for 19:return $CH$