Algorithm 2 FDRT’s MEC Server Parameter Aggregation.

INPUT: mobile device agent parameters $\left\{{\theta }^u\right\}$ OUTPUT: global model parameter ${\theta }^e$ // $u\in U_e$ means that MD $u$ is within the coverage of MEC server $e$, where $U_e$ denotes the set of MDs within the coverage of $e$ // $e^{\prime }\in E_e$ means that MEC server $e^{\prime }$ is a server near $e$, where $E_e$ denotes the set of servers near $e$ // $get\_MD\_num\left(e\right)$ denotes the number of MDs within range of MEC server $e$ 1:  ${\theta }_{temp}^e\leftarrow 0$; 2:  for $u$ in $U_e$ do  3:      ${\theta }_{temp}^e\leftarrow {\theta }_{temp}^e+{\theta }^u$; 4:  end for 5:  ${\theta }_{temp}^e\leftarrow {\theta }_{temp}^e/\left|U_e\right|$; 6:  $count\leftarrow get\_MD\_num\left(e\right)$; 7:  ${\theta }^e\leftarrow count*{\theta }_{temp}^e$; 8:  for $e^{\prime }$ in $E_e$ do 9:      if$\left(get\_MD\_num\left(e^{\prime }\right)>0\right)$ then 10:          ${\theta }^e\leftarrow {\theta }^e+get\_MD\_num\left(e^{\prime }\right)*{\theta }_{temp}^{e^{\prime }}$; 11:          $count\leftarrow count+get\_MD\_num\left(e^{\prime }\right)$; 12:      end if 13:  end for 14:  ${\theta }^e\leftarrow {\theta }^e/count$; 15:  return ${\theta }^e$;