This paper presents a key technological component to efficiently enable multi-user holoconferencing systems, where remote participants can virtually meet represented as 3D volumetric Point Clouds.
Connecting remote people in a hyper-realistic and immersive manner is a major challenge and requirement, recently magnified by the lockdown and the forced social distancing measures the population has had to deal with. This paper presents a key technological component to efficiently enable multi-user holoconferencing systems, where remote participants can virtually meet represented as 3D volumetric Point Clouds. The contribution resides in bringing the traditional MCU concept broadly used in 2D videoconferencing services to emerging 3D holoconferencing scenarios, with the development of a virtualized cloud-based Extended Reality Multipoint Control Unit (XR-MCU). The XR-MCU aims at reducing the requirements in terms of computational resources and bandwidth consumption at the client side, thanks to the development of a set of novel features, like: fusion of volumetric videos from different users, adjustment of Level of Detail (LoD), and removal of non-visible data. The results from an experimental test confirm the benefits of the XR-MCU when compared to a baseline scenario without its usage. These promising results, together with further planned optimizations, open to door to new technological solutions to enable scalable and adaptive 3D holoconferencing services using lightweight devices. The contribution of this paper can therefore provide relevant societal and economic benefits to our society, by enabling hyper-realistic virtual meetings using inexpensive hardware, while overcoming spatial barriers and travel requirements, and minimizing the environmental burden.
Distributed media services, like videoconferencing, have become fundamental for connecting remote people in real-time. Platforms like Skype and Google Hangouts are widely used in a variety of private and professional settings, exchanging large volumes of time-sensitive data with demanding needs in terms of processing and scalability. Due to the common limited computational resources at the client side, Multi-point Control Units (MCUs)  rapidly became core components in video communication systems, managing sessions and communications, and performing additional advanced features like layout and quality adaptability. The demand for such kind of services, and thus also for scalable solutions, has been magnified with the recent outbreak of the Covid-19 pandemic, with an estimation of around one-third of the world’s population experiencing some kind of lockdown or quarantine.