Power-driven VoIP quality adaptation over WLAN in mobile devices

Network parameters such as packet loss and delay have been extensively investigated as the major factors in determining when and how to carry out VoIP quality adaptation to enhance quality of experience. However, a little effort has been put into investigating the impact of non-network parameters such as limited battery resources in mobile devices on the VoIP QoE. Battery life which is not long enough to complete VoIP communication session will adversely affect users´ QoE. In order to mitigate battery life limitation, this paper proposes VoIP quality adaptation scheme whereby an acceptable quality is maintained by changing video send bitrate in order to conserve power and hence, prolong VoIP communication session. Through experiments, preliminary results have shown the effectiveness of the proposed scheme in terms of power saving while maintaining acceptable QoE. The power saving was between 10-30% of the total system power.