A Quality of Experience Handover System for Emerging Multimedia Networks Carlos Quadros, Eduardo Cerqueira Federal University of Para Belém, Brazil {jean, cerqueira}@ufpa.br Augusto Neto Federal University of Ceara Fortaleza, Brazil augusto@deti.ufc.br Antonio Pescapé University of Napoli Federico II Naples, Italy pescape@unina.it Andre Riker, Roger Immich, Marilia Curado University of Coimbra Coimbra, Portugal {riker, immich,marilia}@dei.uc.pt Abstract— The convergence of emerging real-time multimedia services, the increasing coverage of wireless networks and the ever-growing popularity of mobile devices, are leading to an era of user-centric multimedia wireless services. In this scenario, heterogeneous communications will co-exist and ensure that the end-user is always best connected. However, the Quality of Experience (QoE) support for emerging video applications in multi-operator environments remains a significant challenge and is crucial for the success of wireless multimedia systems. This paper presents a Quality of Experience Handover Architecture for Converged Heterogeneous Wireless Networks, called QoEHand. QoEHand allows users of multimedia content to be always best connected in IEEE 802.11e and IEEE 802.16e environments. Simulation results show the impact and benefit of the proposed solution in multi-access and multi-operator wireless scenarios by using objective and subjective QoE metrics. Keywords: Video Streaming; QoE; Wireless networks I. INTRODUCTION The development of new real-time multimedia services, the increasing coverage of heterogeneous wireless networks and the ever-growing popularity of mobile devices, are changing the life-style of users and creating a user-centric multimedia wireless era. In addition, the integration of heterogeneous networks, such as IEEE 802.11 and IEEE 802.16, in multi- access and multi-operator systems, is bringing about revolutionary changes in the Internet by providing new opportunities, introducing better communication channels and raising possibility of providing better Quality of Experience (QoE) assurance for users of wireless services. Emerging multi-access/operator wireless environments will allow clients to be connected to the best QoE-aware wireless access network, where seamless mobility will be combined with respect for the user´s preferences. In this scenario, the creation of novel architectures is required to allow vertical and horizontal QoE-aware handovers in heterogeneous networks. In order to assure connectivity and mobility in heterogeneous systems, the IEEE 802.21/Media Independent Handover Services (MIH) standard was proposed [1], but MIH alone does not provide QoE support for multimedia applications. Due to the heterogeneity of future wireless systems (networks different service classes and applications, as well as links with different capacities), novel QoE architectures (including MIH) with quality estimator, mapping and adaptation mechanisms, are needed to provide QoE support for real-time 2D/3D video streaming in multi-operator and multi- access environments [2-3]. One requirement is to improve the handover decision process by assessing the QoE of users consuming video flows. Another issue is that each access network must support different QoS models (e.g., IEEE 802.11e or IEEE 801.16), and offer the same wireless service classes with different definitions or even service classes with different compositions [4]. Therefore, a QoE mapping must be used to map application requirements and user´s perception into available wireless service classes based on information about the available classes (within or between networks) and the predicted QoE given by the quality estimator. Moreover, in periods of congestion in a selected service class, an adaptation scheme must adjust the quality level of video flows, by selecting a different class to map multimedia packets or by dropping packets in overloaded queues in accordance with the impact they have on the user’s experience. This paper extends MIH with a Quality of Experience Handover Architecture for Converged Heterogeneous Wireless Networks (QoEHand) to allow users of multimedia content to be always best connected in IEEE 802.11e and IEEE 802.16e environments. QoEHand coordinates video quality estimator, mapping and adaptation components in order to provide QoE- aware seamless handovers in multi-access and multi-operator systems. Simulation experiments, by using Network Simulator 2 (NS2) and real real-video sequences, were carried out in multimedia-aware IEEE 802.11e and IEEE 802.16e systems to show the impact of the proposed solution on the user’s perception when compared with MIH. The remainder of the paper is organized as follows. Section II describes some related works. The QoEHand is explained in Section III. Section VI discusses the simulation experiments and results. Concluding remarks are given in Section VI. II. RELATED WORKS Challenges and requirements to create an IEEE 802.21 Media Independence Service Layer to optimize the usage of resources in heterogeneous wireless networks are discussed in [5]. The proposal uses a modular approach to coordinate mobility and video quality estimator components to provide