XR-specific C-DRX Enhancement for UE power saving in 5G NR

Supporting Extended-Reality (XR) services in 5G New Radio (NR) and beyond has been an active area of study and research in the 3rd generation partnership project (3GPP) and other standardization bodies. Existing studies have looked into improving the state-of-art Connected mode Discontinuous Reception (C-DRX) method for power savings in 5G NR, specifically for XR traffic. C-DRX achieves power savings by periodically (typically integer - in multiples of 1ms) switching-off components of UE. Depending on the components that are switched off, different ‘sleep modes’ namely micro sleep, light sleep, and deep sleep provide increased energy savings. For XR, the traffic pattern has been observed to be of Quasi-periodic nature having non-integer periods along with jitter around its mean arrival instant. This jitter introduces unpredictability in the period of operation of the C-DRX method. Existing proposals place dense Wake-up Signals (WUS) which leaves micro sleep to be the only feasible sleep mode due to the stringent latency requirements for XR. In this paper, we propose a method of skipping WUS, that allows XR devices to employ other available sleep modes leading to improved energy savings. Our results show that, compared to the existing proposals, our proposal achieves a significant gain in energy-saving figures (up to 25% for the frame rate of 30 fps).