Next Generation Mobile Networks (NGMNs) together with smart phones evolution have opened new opportunities to deliver mobile services, including voice, data and multimedia applications to the users. However this conflation has brought several challenges in terms of Quality of Experience - QoE of users. Mainly due to degradations with time-varying characteristics in the presense of link heterogeneity, varying packet loss and codec switching. In this paper we propose an analytical quality prediction model which predicts user QoE for conditions that are typically occurring in NGNMs such as network handovers, codec switching and different packet loss rates due to adverse wireless networking conditions. We augment our model with service price as another key factor in QoE representation. We validate quality prediction of our model with subjective tests. Our results show that the quality prediction by our model has correlation of r∈=∈0.923 with subjective ratings.