  Boosting data rates in LTE mobile networks is one of the key features of
LTE-Advanced. This improved user experience is achieved by Carrier Aggregation
(CA), in which the available spectrum of an operator is bundled out of several
frequency bands. Accordingly, the user equipment has to supply multiple
reception chains and therefore consumes considerably more power during a
transmission. On the other hand, transmissions terminate faster, which enables
a quick switchover into energy-saving mode. In order to examine these opposed
facts, empirical analyses of existing devices are first carried out.
Subsequently, we present a new CA enhancement of an existing context-aware
power consumption model which incorporates the development density of the
environment and the mobile device mobility. Based on the extended model we
perform a detailed power consumption analysis and show that CA leads to power
savings of 31% if the data rate doubled for large file transmissions. In
addition, we show that CA can lead to power savings even from a data rate
increase of 25%, regardless of mobility and urban development density. Besides,
the measurement results show that CA operated in the same band leads to a lower
power consumption than inter-band CA.
