On the Capability of QoE Improvement Based on the Adjustment of RLC Parameters

Abstract

The constant evolution in mobile communications networks have led operators to seek new techniques to optimize their mobile networks with the objective of satisfying the expectations of the users. In this way, traditional optimization techniques based on improving radio indicators, have given way to new techniques based on improving the quality of experience (QoE) perceived by users. This paper is focused on analyzing the impact of the adjustment of radio link control (RLC) layer configuration parameters on the QoE perceived by the users of two different types of services. Firstly, an evaluation of the QoE experienced by the user of a real-time video streaming service with respect to the transmission buffer size of the RLC layer in unacknowledged mode (UM) has been carried out. Secondly, the QoE perceived by the user of a file transfer service in relation to the variation of the configuration parameters of the RLC layer in acknowledged mode (AM) has been evaluated. The study, which has been carried out in a simulated cellular environment, has been performed for different system bandwidth values, thus proving the relationship between the QoE perceived by the users, the optimal RLC configuration parameters values and the available bandwidth.

QoE Optimization in a Live Cellular Network through RLC Parameter Tuning

“…Although TM has been proposed in the literature to perform optimization tasks for radio network parameters [ 18 ], to the best of our knowledge, this is the first work to use TM for QoE optimization in mobile networks. In this sense, this paper extends the contribution of [ 17 ] in which an assessment of the impact of the RLC layer configuration on QoE is presented. The main contributions of this paper are detailed as follows.…”

“…As in [ 17 ], in this work, the model defined in [ 22 ] to approximate the MOS is used. In addition to the PSNR, this model considers aspects such as the packet loss rate and the frame degradation during transmission.…”

“…The AM RLC parameters used were the t-PollRetransmit and the t-StatusProhibit timers. The selection of these parameters was made based on the performance of the RLC AM and following the study carried out in [ 17 ].…”

“…The simulation scenario used to assess the optimization algorithm proposed in this paper was the same as that used in [ 17 ]. This scenario consisted of two LTE cells with a distance of 100 m between them.…”

“…Furthermore, none of these studies discusses the effect that a misconfiguration of the RLC layer may cause on the QoE. In [ 17 ], a preliminary analysis of how the RLC configuration parameters affect the QoE perceived by the users is presented, but this work does not propose a method to optimize it.…”