In this paper the measurement concept of QoE related to mobile video streaming in 3G network environment is introduced. The state-of-the-art tools created for automatic data capturing in field experiments are compared. Results of a semi-Living Lab experiment using the MyExperience in-situ measurement tool are presented and analyzed. Five orthogonal QoE aspects are proposed by performing Principal Component Analysis on 17 question items from the questionnaires. Technical-quality related QoE aspects are modeled by the technical QoS parameters (at wireless infrastructure and network level) measured during the experiment. It is shown that QoE of mobile video streaming is influenced by the QoS and by the context also.