What are the causes and solutions for the higher battery drain on 5G compared to 4G-LTE?
According to a new Ookla report, smartphone users accessing 5G networks experience higher battery drain than for those using 4G-LTE, of between 6% and 11%, depending on the System on Chip (SoC) in their device.
Newer chipsets are also showing a better performance, although it will take time to close the gap from only SoC perspective.
Qualcomm’s Snapdragon is the most efficient Android SoC. Qualcomm’s latest flagship SoC, the Snapdragon 8 Gen 2, recorded the lowest battery drain of all SoCs in their analysis, recording 31% for users on 5G, and 25% on 4G-LTE.
Besides, the industry is working on network-driven capabilities that could help to reduce the device power consumption on 5G. The most attractive ones so far are:
1. RRC_INACTIVE State: 5G introduces the RRC_INACTIVE state, where the RRC connection is released when not in use but the device context is retained. This consumes less power than the RRC_IDLE state.
2. DRX + WUS: Discontinuous reception enables a device in the RRC_CONNECTED state to periodically, instead of constantly, monitor the physical downlink control channel (PDCCH) to save power. Also, Wake-up Signal (WUS) ensures that the device wakes up only when it receives this signal from the network.
3. BWP Adaptation: 5G uses large bandwidths, but it is unnecessary for a UE to always work on large bandwidth. Bandwidth Part is proposed in 5G to enable UEs to work on narrower bandwidths without sacrificing user experience. For this the base station to dynamically switch between BWPs based on the UE’s traffic volume.
4. Maximum MIMO Layers Reduction: Depending the situation, the device can request to reduce the number of MIMO layers and therefore the base station configures fewer MIMO layers for the UE through an RRC reconfiguration message. In this way, the UE can deactivate some antennas to save power.
