Stochastic modeling for energy efficiency in modified directional discontinuous reception for LTE-5G networks

Fifth-generation (5G) networks deal with high-frequency data rates, ultra-low latency, more reliability, massive network capacity, more availability, and a more uniform user experience. To validate the high-frequency rates, 5G networks engage beam searching operation. By adopting a beam searching state between the short and long sleep, one can reduce the system's delay. The energy consumption of user equipment (UE) in 5G networks is much higher than in the 4G networks. To reduce the energy consumption and increase the energy saving in UE, Long-Term Evolution (LTE)-5G networks adopt the discontinuous reception (DRX) scheme with a fixed number of short sleep. LTE-DRX without beam search operation (i.e., beam alignment) cannot work in 5G networks. Hence, keeping this scenario in mind, we have modeled a new modified directional discontinuous reception (MD-DRX) mechanism for LTE-5G networks. The MD-DRX mechanism captures the behavior of a beam searching, an inactive, an active, a long sleep, an ON, and a short sleep states. The short sleep state consists of a maximum $M$ short sleep. To get the optimal energy saving and energy consumption (i.e., energy efficiency) from the MD-DRX mechanism, it is required to check the system's throughput. The trade-off between energy saving/energy consumption and throughput will provide the system's optimal energy saving and optimal energy consumption. In this paper, we have obtained the system's optimal energy saving and throughput by optimizing the maximum short sleep and short sleep duration. To get the energy efficiency for LTE-5G networks, the trade-off between average energy consumption/energy saving and throughput is shown.