In this paper, we study how much bundling video frames prior
to transmission can save energy of the LTE UE while streaming
video over the LTE uplink. The scenario is depicted in Figure
1. The video camera transmits the stream to an LTE mobile device
that acts as a gateway. If the video frames are transmitted
while generated, the LTE radio will be continuously on. However,
if the video frames are bundled for a few seconds to a larger
burst of data before transmission, the LTE radio can leverage the
in-built power saving mechanisms, namely discontinuous reception/transmission
(DRX/DTX). In this paper, we show through simulations
how much energy can be saved in this way.
Many studies on the energy consumption of mobile devices and
how to optimize it have been already conducted, especially in the
context of Wi-Fi and 3G communication. For example, Chandra
et al. were among the first to study mobile device energy savings
using server side traffic shaping[4] and Balasubramanian et
al. measured the energy of 3G communication[2]. Hoque et al. investigated
different video stream delivery mechanisms from the energy
consumption perspective [8], surveyed energy efficient mobile
streaming[7], and studied the impact of streaming traffic bundling
on the energy consumption [6, 10]. A few papers have studied LTE:
Huang et. al[9] and Dusza et. al[5] both measured the energy ef-
ficiency of LTE communication. A commonality between all these
papers is their focus on downstream communications, whereas our
focus is on upstream video transmission over LTE.
Our simulation results reveal that bundling is highly effective
way to save energy and that only one second of bundling is enough
in some cases to cut the energy consumption to half. Video bitrate
has a clear impact on the energy savings achievable so that high