A study on the effect of transmission power adaptation and multi-hop path usage on power consumption and QoS in adaptive mobile video delivery

Smart-phones have become a ubiquitous technology, replacing a large number of previously independent digital devices. While the functionality of these smart mobile devices is increasing exponentially, the devices are limited in terms of practical use because of their battery life. This paper introduces PowerHop, a novel algorithm which combines three linked approaches for reducing the power consumption of a smart-phone while it is transmitting video content. The first approach is to dynamically reduce the transmission power of the device´s Wireless Network Interface Card (WNIC). The side-effect of a reduction in the transmission power is that the range of the transmissions is also reduced. The second approach of PowerHop compensates for this range reduction by transmitting data to an intermediary relay node. The final approach of the PowerHop algorithm is to adapt the video quality in response to loss on the transmission link. The effect of the transmission power adaptation, multi-hop paths and the video quality adaptation, on the power consumption of a device is measured in real-world tests on Android devices. In addition, the effect of the transmission strategy on the Quality of Service (QoS) of the video transmission application is also analyzed.