Klaus I. Pedersen’s research while affiliated with Nokia and other places

Extended reality (XR) is unlocking numerous possibilities and continues attracting individuals and larger groups across different business sectors. With Virtual reality (VR), Augmented reality (AR), or Mixed reality (MR) it is possible to improve the way we access, deliver and exchange information in education, health care, entertainment, and many other aspects of our daily lives. However, to fully exploit the potential of XR, it is important to provide reliable, fast and secure wireless connectivity to the users of XR and that requires refining existing solutions and tailoring those to support XR services. This article presents a tutorial on 3GPP 5G-Advanced Release 18 XR activities, summarizing physical as well as higher layer enhancements introduced for New Radio considering the specifics of XR. In addition, we also describe enhancements across 5G system architecture that impacted radio access network. Furthermore, the paper provides system-level simulation results for several Release 18 enhancements to show their benefits in terms of XR capacity and power saving gains. Finally, it concludes with an overview of future work in Release 19 that continues developing features to support XR services.

Extended reality (XR) services form the basis of the metaverse, a fully immersive experience where users can interact with each other and digital objects in a three-dimensional real or imagined digital space. Past and ongoing standardization activities focus on enabling cellular networks to effectively support XR to ensure that the metaverse can be enabled everywhere. One enabling feature is application awareness (AA) within the service provisioning framework of 5G-Advanced. AA is extending the current quality of service (QoS) model to support a finer QoS granularity and add more detailed application information to improve radio resource management and eventually enhance users' immersive experience. Current and future AA innovations will enable cellular networks to improve system capacity and further optimize service provisioning to fit specific application needs. In this article, we present a comprehensive overview of AA for XR services in cellular networks and future research directions in that area.

Mechanisms for data recovery and packet reliability are essential components of the upcoming 6 th generation (6G) communication system. In this paper, we evaluate the interaction between a fast hybrid automatic repeat request (HARQ) scheme, present in the physical and medium access control layers, and a higher layer automatic repeat request (ARQ) scheme which may be present in the radio link control layer. Through extensive system-level simulations, we show that despite its higher complexity , a fast HARQ scheme yields > 66 % downlink average user throughput gains over simpler solutions without energy combining gains and orders of magnitude larger gains for users in challenging radio conditions. We present results for the design trade-off between HARQ and higher-layer data recovery mechanisms in the presence of realistic control and data channel errors, network delays, and transport protocols. We derive that, with a suitable design of 6G control and data channels reaching residual errors at the medium access control layer of 5 × 10 −5 or better, a higher layer data recovery mechanism can be disabled. We then derive design targets for 6G control channel design, as well as promising enhancements to 6G higher layer data recovery to extend support for latency-intolerant services.

Extended reality (XR) is unlocking numerous possibilities and continues attracting individuals and larger groups across different business sectors. With Virtual reality (VR), Augmented reality (AR), or Mixed reality (MR) it is possible to improve the way we access, deliver and exchange information in education, health care, entertainment, and many other aspects of our daily lives. However, to fully exploit the potential of XR, it is important to provide reliable, fast and secure wireless connectivity to the users of XR and that requires refining existing solutions and tailoring those to support XR services. This article presents a tutorial on 3GPP 5G-Advanced Release 18 XR activities, summarizing physical as well as higher layer enhancements introduced for New Radio considering the specifics of XR. In addition, we also describe enhancements across 5G system architecture that impacted radio access network. Furthermore, the paper provides system-level simulation results for several Release 18 enhancements to show their benefits in terms of XR capacity and power saving gains. Finally, it concludes with an overview of future work in Release 19 that continues developing features to support XR services.

In this tutorial we present recipes for dynamic systemlevel simulations (SLSs) of 5G and beyond cellular radio systems. A key ingredient for such SLSs is selection of proper models to make sure that the performance determining effects are properly reflected to ensure output of realistic radio performance results. We therefore present a significant number of SLS models and related methodologies for a variety of use cases. Our focus is on generally accepted models that are largely supported by academia and industrial players and adopted by 3GPP as being realistic. Among others, we touch on deployment models, traffic models, non-terrestrial cellular networks with satellites, SLS methodologies for Machine Learning (ML) enabled air-interface solutions, and many more. We also present several recommendations for best practices related to preparing and running detailed SLS campaigns, and agile software engineering considerations. Throughout the article we use the 3GPP defined 5G and 5G-Advanced systems to illustrate our points, extending it also into the 6G-era that is predicted to build on alike SLS methodologies and best practices.