This article proposes a novel energy-efficient multimedia delivery system called EStreamer. First, we study the relationship between buffer size at the client, burst-shaped TCP-based multimedia traffic, and energy consumption of wireless network interfaces in smartphones. Based on the study, we design and implement EStreamer for constant bit rate and rate-adaptive streaming. EStreamer can improve battery lifetime by 3x, 1.5x, and 2x while streaming over Wi-Fi, 3G, and 4G, respectively.
Shaping constant bit rate traffic into bursts has been proposed earlier for UDP-based multimedia streaming to save Wi-Fi communication energy of mobile devices. The relationship between the burst size and energy consumption of wireless interfaces is such that the larger is the burst size, the lower is the energy consumption per bit received as long as there is no packet loss. However, the relationship between the burst size and energy in case of TCP traffic has not yet been fully uncovered. In this paper, we develop a power consumption model which describes this relationship in wireless multimedia streaming scenarios. Then, we implement a cross-layer stream delivery system, EStreamer. This system relies on a heuristic derived from the model and on client playback buffer status to determine a burst size and provides as small energy consumption as possible without jeopardizing smooth playback. The heuristic greatly simplifies the deployment of EStreamer compared to most existing solutions by ensuring energy savings regardless of the wireless interface being used. We show that in the best cases using EStreamer reduces energy consumption of a mobile device by 65 , 50-60 and 35 while streaming over Wi-Fi, LTE and 3G respectively. Compared with existing energy-aware applications energy consumption can be reduced by 10-55 further. Energy consumption of mobile devices is a great concern and streaming applications are among the most power hungry ones. We evaluate the energy saving potential of shaping streaming traffic into bursts before transmitting it over 3G and LTE networks to smartphones. The idea is that in between the bursts, the phone has sufficient time to switch from the high-power active state to low-power states. We investigate the impact of the network parameters, namely inactivity timers and discontinuous reception, on the achievable energy savings and on the radio access network signaling load. The results confirm that traffic shaping is an effective way to save energy, even up to 60 of energy saved when streaming music over LTE. However, we note large differences in the signaling load. LTE with discontinuous reception and long inactivity timer value achieves the energy savings with no extra signaling load, whereas non-standard Fast Dormancy in 3G can multiply the signaling traffic by a factor of ten.