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Emerging 5G/6G use cases span various industries, necessitating flexible solutions that leverage emerging technologies to meet diverse and stringent application requirements under changing network conditions. The standard 5G RAN solution, retransmission, reduces packet loss but can increase transmission delay in the process. Random Linear Network Coding (RLNC) offers an alternative by proactively sending combinations of original packets, thus reducing both delay and packet loss. Current research often only simulates the integration of RLNC in 5G while we implement and evaluate our approach on real commercially available hardware in a real-world deployment. We introduce Flexible Network Coding (FlexNC), which enables the flexible fusion of several RLNC protocols by incorporating a forwarder with multiple RLNC nodes. Network operators can configure FlexNC based on network conditions and application requirements. To further boost network programmability, our Recoder in the Network (RecNet) leverages intermediate network nodes to join the coding process. Both the proposed algorithms have been implemented on OpenAirInterface and extensively tested with traffic from different applications in a real network. While FlexNC adapts to various application needs of latency and packet loss, RecNet significantly minimizes packet loss for a remote user with minimal increase in delay compared to pure RLNC.

While 5G mobile communication systems are currently in deployment, researchers around the world have already started to discuss 6G technology and funding agencies started their first programs with a 6G label. Although it may seem like a good idea from a historical point of view with returning generations every decade, this contribution will show that there is a great risk of introducing 6G labels at this time. While the reasons to not talk about 6G yet are manifold, some of the more dominant ones are i.) there exists a lack of real technology advancements introduced by a potential 6G system; ii.) the flexibility of the 5G communication system introduced by softwarization concepts, such as in the Internet community, allows for daily updates; and iii.) introducing widespread 6G discussions can have a negative impact on the deployment and evolution of 5G with completely new business cases and customer ecosystems compared to its predecessors. Finally, as we do not believe that 5G is the end of our journey, we will provide an outlook on the future of mobile communication systems, independent of the current mainstream discussion.

Augmented Reality (AR) devices are commonly head-worn to overlay context-dependent information into the field of view of the device operators. One particular scenario is the overlay of still images, either in a traditional fashion, or as spherical, i.e., immersive, content. For both media types, we evaluate the interplay of user ratings as Quality of Experience (QoE) with (i) the non-referential BRISQUE objective image quality metric and (ii) human subject dry electrode EEG signals gathered with a commercial device. Additionally, we employ basic machine learning approaches to assess the possibility of QoE predictions based on rudimentary subject data. Corroborating prior research for the overall scenario, we find strong correlations for both approaches with user ratings as Mean Opinion Scores, which we consider as QoE metric. In prediction scenarios based on data subsets, we find good performance for the objective metric as well as the EEG-based approach. While the objective metric can yield high QoE prediction accuracies overall, it is limited i its application for individual subjects. The subject-based EEG approach, on the other hand, enables good predictability of the QoE for both media types, but with better performance for regular content. Our results can be employed in practical scenarios by content and network service providers to optimize the user experience in augmented reality scenarios.

With the continuous growth in the consumer markets of mobile smartphones and increasingly in augmented reality wearable devices, several avenues of research investigate the relationships between the quality perceived by mobile users and the delivery mechanisms at play to support a high quality of experience for mobile users. In this paper, we present the first study that evaluates the relationships of mobile movie quality and the viewer-perceived quality thereof in an augmented reality setting with see-through devices. We find that participants tend to overestimate the video quality and exhibit a significant variation of accuracy that leans onto the movie content and its dynamics. Our findings, thus, can broadly impact future media adaptation and delivery mechanisms for this new display format of mobile multimedia., Comment: Accepted to Signal Processing: Image Communication

The network transport of 3D video, which contains two views of a video scene, poses significant challenges due to the increased video data compared to conventional single-view video. Addressing these challenges requires a thorough understanding of the traffic and multiplexing characteristics of the different representation formats of 3D video. We examine the average bitrate-distortion (RD) and bitrate variability-distortion (VD) characteristics of three main representation formats. Specifically, we compare multiview video (MV) representation and encoding, frame sequential (FS) representation, and side-by-side (SBS) representation, whereby conventional single-view encoding is employed for the FS and SBS representations. Our results for long 3D videos in full HD format indicate that the MV representation and encoding achieves the highest RD efficiency, while exhibiting the highest bitrate variabilities. We examine the impact of these bitrate variabilities on network transport through extensive statistical multiplexing simulations. We find that when multiplexing a small number of streams, the MV and FS representations require the same bandwidth. However, when multiplexing a large number of streams or smoothing traffic, the MV representation and encoding reduces the bandwidth requirement relative to the FS representation.

The broad proliferation of mobile devices in recent years has drastically changed the means of accessing the World Wide Web. Describing a shift away from the desktop computer era for content consumption, predictions indicate that the main access of web-based content will come from mobile devices. Concurrently, the manner of content presentation has changed as well; web artifacts are allowing for richer media and higher levels of user interaction which is enabled through increasing access networks speeds. This article provides an overview of more than two years of high level web page characteristics by comparing the desktop and mobile client versions. Our study is the first long-term evaluation of differences as seen by desktop and mobile web browser clients. We showcase the main differentiating factors with respect to the number of web page object requests, their sizes, relationships, and web page object caching. We additionally highlight long-term trends and discuss their future implications.

In this paper, we present an evaluation of the Ethernet traffic for host and attendees of the popular opensource web conferencing system DimDim. While traditional Internet-centric approaches such as the MBONE have been used over the past decades, current trends for web-based conference systems make exclusive use of application-layer multicast. To allow for network dimensioning and QoS provisioning, an understanding of the underlying traffic characteristics is required. We find in our exemplary evaluations that the host of a web conference session produces a large amount of Ethernet traffic, largely due to the required control of the conference session, that is heavily-tailed distributed and exhibits additionally long-range dependence. For different groups of activities within a web conference session, we find distinctive characteristics of the generated traffic.