While operators have started deploying fourth generation (4G) wireless communication systems,which could provide up to 1Gbps downlink peak data rate,the improved system capacity is still insufficient to meet the drastically increasing demand of mobile users over the next decade.The main causes of the above-mentioned phenomenon include the fol lowing two aspects:1) the growth rate of the network capacity is far below that of user’s demand,and 2) the relatively deterministic wireless access network (WAN) architecture in the existing systems cannot accommodate the prominent increase of mobile traffic with space-time domain dynamics.In order to address the above-mentioned challenges,we investigate the time-spatial consistency architecture for the future WAN,whilst emphasiz ing the critical roles of some spectral-efficient techniques such as Massive multiple-input multiple-output (MIMO),full-duplex (FD) operation and heterogeneous networks (Het Nets).Furthermore,the energy efficiency (EE) of the HetNets under the proposed architecture is also evaluated,showing that the proposed user-selected uplink power control algorithm outperforms the traditional stochastic-scheduling strategy in terms of both capacity and EE in a two-tier HetNet.The other critical issues,including the tidal effect,the temporal failure owing to the instantaneously increased traffic,and the network wide load-balancing problem,etc.,are also anticipated to be addressed in the proposed architecture.