On the User Performance of LTE UE Power Savings Schemes with Discontinuous Reception in LTE

The UTRAN long-term evolution (LTE) specifications provide flexible means to achieve micro-sleep operation for user equipment (UE) even though it is in active mode and running a service. By means of a discontinuous reception (DRX) framework, pauses in the transmission due to natural traffic characteristics or network prioritization can be utilized. The specifications give a number of options to optimize the performance. In this paper two of those possibilities are compared. Long DRX with the use of an inactivity timer is compared to the usage of short DRX on top of long DRX. The performance is evaluated in terms of user throughput, power consumption, and network performance, while using a realistic RF modem power consumption model for the UE. For bursty traffic, short DRX shows a gain of up to 100% over DRX with just an inactivity timer, when measuring throughput per power unit consumed in case of one or multiple users being present in the cell.