Current Consumption Measurements with a Carrier Aggregation Smartphone

Carrier Aggregation (CA) is introduced in LTE release 10 to improve data rates by allowing the User Equipment (UE) to receive data on more than one LTE carrier. The related increased complexity is expected to affect the UE current consumption, but yet no empirical evaluation has been published on this topic. Currently there are only theoretical expansions of LTE release 8 power models available, but this article presents the first publicly available current consumption measurements on a commercial CA-capable UE. In this work it is examined how the activation and use of CA (10 + 10 MHz) affects the UE current consumption with different traffic profiles such as FTP or web browsing. For a large FTP download the average CA current consumption is reduced 13% compared to single-carrier 10 MHz due to increased data rate and extended idle time, which allows the UE to enter a low-current sleep mode. For small data bursts, such as keep-alive messages, configuring CA results in 17 mA average current increase during RRC connected state inactivity periods. Depending on the UE background activity, this could translate into 3% to 8% reduction of the UE's stand-by battery life.