Energy Efficient RRM Relaxation for Reduced Capability UEs in 5G Networks

Radio resource management (RRM) relaxation has been introduced in 3GPP NR Release 16 as a key feature for optimizing UE power saving. It can be applied for UEs under “low mobility” and “cell edge” criteria. In this study, we investigate its benefit in addition to discontinuous reception (DRX) for reduced capability (RedCap) new radio (NR) UEs, a new type of low-cost device, for which the power saving is a key requirement. We provide comprehensive simulation results that quantify energy saving by applying RRM relaxation for stationary and pedestrian RedCap UEs with different “cell edge” criteria and DRX settings. In addition, we evaluate the impact in terms of handover failures and packet delay. The simulation analysis shows that dynamic adjustment of “cell edge” criteria of RRM relaxation is a more power-efficient solution that can achieve up to 64% to 96% RRM measurement energy saving.