A testbed for QoE-based multimedia streaming optimization in heterogeneous wireless networks

Over the top services such as video telephony or IPTV are nowadays offered in mobile networks. The mobile users, however, expect not only service connectivity, but also demand on service quality. To meet user expectations and optimize the multimedia streaming, operators have to make a trade-off between service quality and the resources allocated for the service offering. However, due to the subjective nature of quality perception, multimedia streaming strategies must be evaluated in laboratory environments before offering them to the users. The contribution of this paper is an experimental testbed that enables to merge user experience with cross-layer parameters of multimedia streaming in wireless networks. The testbed consist of an audiovisual client, a network infrastructure, a control module, and a demonstrator. Thus, experiments can be performed to evaluate streaming quality aspects that are related to 1) uncompressed video processing (e.g. rescaling), 2) audio and video coding, 3) packetization, 4) buffering, 5) transmission link, and 6) quality adaptation during active sessions. The test conditions can be flexibly defined through an event-based test definition concept. The tests can be automatically processed and data can be collected. Selected results of tests conducted in the testbed are presented in the paper. The demonstrator that is deployed on top of the testbed enables visualisation of the streaming quality for various configurations in real-time. This way, the testbed is a relevant contribution to the design of Quality of Experience (QoE) aware applications in future wireless networks.