Video telephony over downlink LTE systems with/without QoS provisioning

More and more video application are being carried on wireless systems with the development of the smart phones. However, the performance of these applications is lack of study, especially for the most advanced LTE networks. In this paper, we investigate the performance of the video telephony over the LTE downlink systems with and without QoS provisioning. The simulation results using two classical algorithms: proportional fair scheduler (PF) and proportional fair scheduler with minimum/maximum rate constraints (PFMR) are presented. Both pure video telephony traffic scenario and two-service scenario of mixed video with full buffer traffics are considered in this paper. The simulation results show that the video capacity is mainly limited by the delay of the video users and the video capacity is increased using PFMR compared with PF, which shows the benefit of providing QoS provisioning. The paper also shows the delay and throughput is highly related to the geometry of the users. The worse the user's geometry is, the user experiences the longer delay and achieves the smaller throughput.