Algorithm 1 Content Placement based on CE method (CPCE)

1:User association under N-Best strategy. 2:Generate content placement request samples of UEs ${\mathit{q}}_{\mathit{m}}$ based on Zipf distribution. Map BSs ⟷ Decision-making entities in CE method. 3:Map the content placement strategy set ⟷ Strategies in CE method. 4:Map the sum backhaul load ⟷ Fitness value in CE method. 5:Execute CPCE. 6:Map the obtained solution into the best content placement strategies of BSs and output $\mathbf{Y}$.