Towards Energy Efficient Multimedia Streaming in Mobile Devices
Authors
Abstract
The progress of technology allowed the Internet access wherever we are and wherever we go. Despite the emerging of new technologies that enable access to the Internet anywhere, such as the cellular networks, the IEEE 802.11 technology is still one of the most used, being present in almost every electronic device.The mobile devices are now embedded in the daily user routines and the smarphones have an important role in this connection between people and technology. In fact, the mobile devices have been steadily growing in recent years with the Android devices reaching the milestone of 1 million devices activated every day. Since these devices are constantly used and, most of the time, connected to the Internet, its battery lifetime is becoming a concern.
The IEEE 802.11 interface is one of the components in Android devices responsible for a large part of the energy consumption. Moreover, the most implemented IEEE 802.11 power save modes in the Android devices do not bring any energy reduction when the users are watching a video transmitted over streaming. This is a critical problem, since it is expected that, in 2017, the video traffic will represent 66.5% of all mobile traffic.
The facts presented showed the importance of proposing new mechanisms to op- timize the energy consumption in Android devices, in order to achieve a tradeoff between the performance and the energy consumed by the device. Therefore, this work presents the IEEE 802.11 technology, with a focus on the Media Access Control (MAC) layer and the power save mechanisms defined in the standard. Some techniques presented in the literature, which aim to optimize the energy consumption in IEEE 802.11, are discussed and the methodologies to assess the IEEE 802.11 energy consumption are presented. A measurement testbed setup is described and allows the assessment of the energy consumption in Android devices. This work ends with an analysis of a set of tests regarding the energy consumed by the IEEE 802.11 interface and the correspondent power save mode mechanisms implemented in the Android devices.