An Empirical LTE Smartphone Power Model with a View to Energy Efficiency Evolution

Smartphone users struggle with short battery life, and this affects their device satisfaction level and usage of the network. To evaluate how chipset manufacturers and mobile network operators can improve the battery life, we propose a Long Term Evolution (LTE) smartphone power model. The idea is to provide a model that makes it possible to evaluate the effect of different terminal and network settings to the overall user equipment energy consumption. It is primarily intended as an instrument for the network engineers in deciding on optimal network settings, but could also be beneficial for chipset manufacturers to identify main power consumers when taking actual operating characteristics into account. The smartphone power consumption model includes the main power consumers in the cellular subsystem as a function of receive and transmit power and data rate, and is fitted to empirical power consumption measurements made on state-of-the-art LTE smartphones. Discontinuous Reception (DRX) sleep mode is also modeled, because it is one of the most effective methods to improve smartphone battery life.Energy efficiency has generally improved with each Radio Access Technology (RAT) generation, and to see this evolution, we compare the energy efficiency of the latest LTE devices with devices based on Enhanced Data rates for GSM Evolution (EDGE), High Speed Packet Access (HSPA), and Wi-Fi*. With further generations of RAT systems we expect further improvements. To this end, we discuss the new LTE features, Carrier Aggregation (CA) and Enhanced Physical Downlink Control Channel (EPDCCH), from an energy consumption perspective.Not surprisingly, the conclusion is that having the cellular subsystem ON, and in addition, transmit powers above 10 dBm, have the largest effect on UE power consumption, and that the combination of high data rates and long sleep periods is the optimal combination from a user equipment energy-saving perspective