User's requirements have become a key factor for any Quality of Service (QoS) management model to succeed. The advent and rise of new broadband services and network architectures (Triple-Play-Services, NGN…) depends on the ability of providers to achieve user's expectations in these scenarios. For that reason, the overall end user's perception (Quality of Experience -QoE) must be audited, on a regular basis, to address changing user's needs. This paper presents a general system developed to evaluate QoE on IP networks. The system architecture is designed to be capable of emulating multi agent networks and dynamically changing conditions. In addition, the results of a Web browsing QoE experiment, laid out within this emulation system, are described. The experiment was conducted on the basis of ITU-T Recommendation G.1030, and aimed to update the perceptual model, provided in this Recommendation, to today's user requirements and technical improvements.

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This paper presents a novel architecture for optimizing the HTTP-based multimedia delivery in multi-user mobile networks. This proposal combines the usual client-driven dynamic adaptation scheme DASH-3GPP with network-assisted adaptation capabilities, in order to maximize the overall Quality of Experience. The foundation of this combined adaptation scheme is based on two state of the art technologies. On one hand, adaptive HTTP streaming with multi-layer encoding allows efficient media delivery and improves the experienced media quality in highly dynamic channels. Additionally, it enables the possibility to implement network-level adaptations for better coping with multi-user scenarios. On the other hand, mobile edge computing facilitates the deployment of mobile services close to the user. This approach brings new possibilities in modern and future mobile networks, such as close to zero delays and awareness of the radio status. The proposal in this paper introduces a novel element, denoted as Mobile Edge-DASH Adaptation Function, which combines all these advantages to support efficient media delivery in mobile multi-user scenarios. Furthermore, we evaluate the performance enhancements of this content-and user contextaware scheme through simulations of a mobile multimedia scenario.Mobile multimedia traffic has been experiencing a dramatic increase in the last years, dominated by the explosion of media delivery through Dynamic Adaptive Streaming over HTTP (DASH). This approach, standardized by MPEG as ISO/IEC CD 23009-1 and adopted by 3GPP as 3GP-DASH, splits media contents in short media segments. These chunks can be made available at different quality versions, allowing users to switch between different quality representations from one interval to the following one. In this way, multimedia services are endowed with client-driven dynamic adaptation capabilities, which is a crucial feature for reacting to variable channel conditions. In AVC-based DASH (DASH-AVC), media content is split in K media segments (AVC k in Fig. 1a) available at N different representations (AVC n in Fig. 1a), corresponding to different quality levels. Each combination of media segment and quality representation is described as a unique HTTP object in a Media Presentation Description (MPD) file, and can be independently retrieved through HTTP GET requests. Therefore, at each time slot, the user device requests a unique video representation.SVC-based DASH (DASH-SVC) allows more flexible delivery schemes since different layers (base layer and enhancement layers) are split into different HTTP objects containing additive information. Each HTTP object in the MPD file represents a quality layer of a video segment. When client devices select the most suitable media representation (SVC 1 -SVC n objects in Fig. 1b) for a media segment (SVC k in Fig. 1b), the different layers are transmitted over the network as standalone HTTP transactions.Dynamic content delivery reacts to the specific network conditions based on either quick client-dri...

In the context of ultra‐dense heterogeneous networks in 5G, we focus on the load balancing problem of elastic traffic in a single macrocell that is supported by a number of small cells. Each small cell is modeled by a single‐class processor sharing queue, whereas the macrocell is modelled by a multiclass processor sharing queue. We assume that the macrocell is always consuming energy, while a small cell can be switched off when it is idle with the setup delay penalty. As the main contribution, aimed at minimizing the weighted sum of the mean delay and the mean power consumption in the system, we develop static and dynamic load balancing policies that take into account the setup delay. All the obtained results are analytically founded. The performance of the static policy is evaluated using the achieved analytical expressions, which include the static optimal probabilities achieved before, whereas for the dynamic policy we need to perform simulations using previously obtained numerical results from the first policy iteration procedure. As concluded, numerical results indicate that the dynamic policy outperforms the static policy under realistic settings.

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