Algorithm 2 Update pheromone matrix when visiting a communication node

Input:$P_r$, $P_{net}$, $M_{trace}$ Output:$P_r^{\prime }$, $P_{net}^{\prime }$, $M_{trace}^{\prime }$ 1:$P_{net}^{\prime }\leftarrow P_{net}+P_r.\ast M_{trace}$ 2:$P_r^{\prime }\leftarrow P_{net}^{\prime }$ 3:$M_{trace}^{\prime }\leftarrow 0$