Algorithm 1 AP-based CP location and SN-CP association optimization algorithm

1:Initialize ${\mathbf{w}}_m$, $\epsilon$, ${\tau }_m^k$, $t_{max}$, $r(m,k)=a(m,k)=0$, and $t=0$. 2:Calculate ${\tau }_m^k$ between any two SNs, and set $s(m,k)$ according to (15). 3:repeat 4:   Update $r(m,k),a(m,k)$ according to (16) and (17), respectively. 5:   Update $t\leftarrow t+1$. 6:until Convergence or $t\ge t_{max}$. 7:Find $\mathcal{C}$ by (18) and establish K and $\mathbf{o}$. 8:Find $\mathbf{L}$ by (19) according to the center of gravity method.