On the Energy-Efficient Deployment for Ultra-Dense Heterogeneous Networks With NLoS and LoS Transmissions

We investigate network performance of ultra-dense heterogeneous networks and study the maximum energy-efficient base station deployment incorporating probabilistic non-line-ofsight and line-of-sight transmissions. First, we develop an analytical framework with the maximum instantaneous received power and the maximum average received power association schemes to model the coverage probability and related performance metrics, e.g., the potential throughput and the energy efficiency (EE). Second, we formulate two optimization problems to achieve the maximum energy-efficient deployment solution with specific service criteria. Simulation results show that there are tradeoffs among the coverage probability, the total power consumption, and the EE. To be specific, the maximum coverage probability with ideal power consumption is superior to that with practical power consumption when the total power constraint is small and inferior to that with practical power consumption when the total power constraint becomes large. Moreover, the maximum EE is a decreasing function with respect to the coverage probability constraint.