QoE oriented cross-layer design of a resource allocation algorithm in beyond 3G systems

The provision of high speed access to Internet and IP-based services is one of the main goals of beyond 3G (B3G) wireless systems. These systems will benefit from cross-layer protocol designs that will introduce interactions between different layers to obtain performance gains. The majority of the research in the field of cross-layer in B3G systems aims at improving quality of service (QoS) system centric metrics such as spectral efficiency, service latency, delay variation (jitter), etc. However, minor attention has been paid to the satisfaction of the subjective quality requirements from human users. With the goal of incorporating the subjective human perception into the cross-layer design of B3G systems, this work carries out an experimental survey of the sensitivity of the user subjective quality to the service response time for the Web browsing application. From the experimental results, a mapping from service response time and user data rate (provided by the wireless link) to mean opinion score (MOS) is derived. The presented results will show that the Web page size plays an important role in the mapping function. The derived mapping function is incorporated into a radio resource allocation algorithm for orthogonal frequency division multiple access (OFDMA) systems. This incorporation is carried out maximizing the aggregate utility over all the users in the cell. Its performance has been compared to that of the multicarrier proportional fair (MPF) under heavy load conditions with a 3G LTE simulator. The results have shown that the proposed methodology can provide an interesting enhancement of the user experienced quality compared to the MPF algorithm.