Shaping Future 6G Networks. Группа авторов

for travel planning. Compared to video conferencing technologies, teleportation supports body language and nonverbal communication, thus guaranteeing better audience engagement and reception of information as well as enhanced productivity during professional events. Finally, even though business travel will always represent an essential resource for many company divisions, from sales to marketing, and from production to research and development, it is expected that teleportation will represent a valuable alternative for future corporate business.

      Teleportation does not refer only to the digital transmission of physical quantities; it will also enable a clear and reproducible digital representation of all human senses, including smell and taste. This will allow, for example, chemical industries to speed up pharmaceutical product preparation and development via virtualization of drug tests,; healthcare companies to implement noninvasive, real‐time diagnostic tools for health monitoring; and agro‐food industries to tailor their offerings to consumer preferences while improving quality control of raw materials and increasing the overall efficiency of the food system.

      Despite these benefits, remote connections via teleportation will introduce significant demands on the 6G network infrastructure, which are not supported today [2]. Specifically, 5G and previous generations have been typically designed to support audio and 2D‐like video communication, where the same data content is broadcast regardless of the viewer’s position. In turn, 3D telepresence adds parallax, meaning that the image changes depending on the viewer’s position and its interaction with the image itself. This approach will radically change the role of the user (from passive video consumer to interactive consumer of multi‐sensory experiences) and lead to a massive increase in the requirements for capturing, transmitting, and interacting with teleportation services. To fully realize an immersive remote experience, all human senses, including touch, smell, and taste, together with video and audio information, will be digitized and transferred across future networks at a data rate up to several terabits per second, which depends on the sensor’s resolution and frame rate: for example, a raw uncompressed hologram with colors, full parallax, and 30 fps would require 4.32 Tbps [1]. The latency requirement will also be very challenging to ensure interactive content provisioning and real‐time communications. While the 5G paradigm sets the round‐trip latency limit in the RAN to 1 ms, 6G technologies will hit the sub‐milliseconds to make the holographic experience smoother and more immersive. Finally, hologram‐based applications will need to process a massive number of streams originating from sensors at different angles of view, thus involving stringent synchronization requirements.

      2.3.3 Digital Twin

      A digital twin is a digital replica of an object, generally characterized by a very high level of fidelity that makes it possible to use the digital version as a reliable representation of the behavior and characteristics of the real object [3]. The concept of digital twins has risen to the forefront of the discussion on product life cycle management thanks to improvements in the design and capabilities of sensors (e.g. video cameras, laser scanners, and lidars) and sensor fusion algorithms, which now allow a rich and faithful representation of the real object, as well as thanks to advances in computation capabilities, which enable the real‐time manipulation and editing of the digital twin. Moreover, the concept of digital twin is often associated to VR and AR, as the digital representation can be visualized through any immersive visualization technique. Thanks to these properties, digital twins can improve the design, engineering, inspection, and maintenance of complex machines and devices. For example, a machine could be remotely inspected without the need for personnel on the ground, without any loss of realism, and with an improved (digital) access to components that would be hard to reach physically. Similarly, mechanics can monitor the performance and status of different components of a vehicle with a high‐fidelity representation without the need for the car to be in the repair center. Additionally, for product development, a digital twin would allow different teams to work on the same product, exploiting a 3D, shared visualization in various remote locations, and can enable advanced simulations of the product behavior.

      In these scenarios, the role of the network is to provide a high‐throughput, low‐latency bit pipe to connect the sensors on the physical product with the computing platforms on which the digital twin is hosted. Several elements contribute to the need for ultrahigh throughput, which would not be supported by 5G technologies, as for the teleportation use case of Section 2.3.2. A digital twin will be generated by a large number of data sources, which need to be distributed around the physical device, and capture different properties, not only the visual aspect. Moreover, the twinning rate, i.e. the rate at which the physical and digital representations are synchronized, could be in the order of hundreds of Hertz, for applications that require a real‐time tracking of the evolution of the physical object. Therefore, the data rate required by digital twin use cases can be in the order of tens of gigabits per second, with the need for high‐capacity links between the different components of a digital twin system (sensors to database, and database to representation). Similarly, when real‐time interaction and control of the physical object through its digital counterpart is required, the latency should be in the sub‐millisecond range. However, if real‐time control is not of interest, or a lower level of fidelity can be accepted, digital twinning applications can tolerate higher latencies and lower throughput. Therefore, 6G networks should also focus on adaptability and openness to the applications, with open interfaces to enable cooperation between the wireless stack and the higher layers, for example, to optimize the number of sources and the twinning rate according to the capabilities of the network, or, vice versa, to allocate more resources according to the needs of the application.

      2.3.4 Smart Transportation

The support of communications in smart transportation is threefold: infotainment, automated driving (AD), and Cooperative Intelligent Transport Systems (C‐ITS). Infotainment (sometimes referred to as navitainment) comprises information, navigation, and entertainment services for drivers and passengers. These services are expected to evolve into extended reality (XR) experiences for passengers and enhanced high‐definition (HD) maps and real‐time information services for drivers, and industry players will need to collaborate in order to satisfy the demand for different in‐vehicle services. AD will experience a gradual increase in capabilities and market share. It is expected that up to 15% of the new vehicles sold in 2030 will have AD in designated conditions and, while the personal vehicle market is also expected to grow, trucks and delivery vehicles have a stronger business incentive compared to personal vehicles, which will drive faster deployment once technology is available [4]. AD requires high volumes of data to be exchanged between cars and the cloud for HD 3D maps, sensor sharing, and computational offloading. Those are the aspects related to individual vehicles, but the goal of C‐ITS is to improve safety and comfort by exchanging information between vehicles and the road infrastructure. Real‐time information will include not only measurements and status from sensors but also path planning and cooperative maneuvers, that are particularly relevant for unmanned aerial vehicles. An important consideration is vulnerable road users (VRUs) such as pedestrians, cyclists, and road workers that can be increasingly protected with solutions based on positions and path crossing alerts enabled by the communication between smartphones (or other personal devices) and vehicles. The former aspects are mostly related to the mobility safety and experience but, in the future, other use cases such as preemptive logistics, fleet management, and telematics will expand and have a key role in society. These services are expected to be implemented by global players in the coming years and, even if they have less stringent requirements on data rate and latency, network coverage and secure private cloud platforms that leverage on network capabilities will be essential for fleet operators and vehicle manufacturers.

      While some of these functionalities can be supported in 5G networks, 6G will play a key role in increasing the flexibility to expand coverage and enable services in all locations and conditions. Continuous coverage will be key if AD should be able to rely on connectivity. Moreover, even lower latencies can enable the use of services at higher traveling speeds. Also, the expected timelines for