Wireless Environment as a Service Enabled by Reconfigurable Intelligent Surfaces: The RISE-6G Perspective

Abstract

This paper introduces the distributed and intelligent integrated sensing and communications (DISAC) concept, a transformative approach for 6G wireless networks that extends the emerging concept of integrated sensing and communications (ISAC). DISAC addresses the limitations of the existing ISAC models and, to overcome them, it introduces two novel foundational functionalities for both sensing and communications: a distributed architecture and a semantic and goal-oriented framework. The distributed architecture enables large-scale and energy-efficient tracking of connected users and objects, leveraging the fusion of heterogeneous sensors. The semantic and goal-oriented intelligent and parsimonious framework, enables the transition from classical data fusion to the composition of semantically selected information, offering new paradigms for the optimization of resource utilization and exceptional multi-modal sensing performance across various use cases. This paper details DISAC's principles, architecture, and potential applications.

Reconfigurable Intelligent Surfaces for Wireless Communications: Overview of Hardware Designs, Channel Models, and Estimation Techniques

“…Continuing prototyping development is highly desired to prove the RIS concept with brand new holographic beamforming technologies, potentially unveiling new technical issues which will require further research efforts. In addition, one of the main goals of the ongoing European Union H2020 RISE-6G project [90], which is the first collaborative project planning to design, prototype, and trial radical technological advances based on RISs to forge a new generation of dynamically programmable wireless propagation environments [16], [17], is to provide low-power and cost-effective RIS hardware designs operating from below 6 GHz to millimeter wave (mmWave) and sub-THz frequencies.…”

Channel Estimation with Simultaneous Reflecting and Sensing Reconfigurable Intelligent Metasurfaces

“…An emerging technology for the future sixth Generation (6G) of wireless communications, enabling dynamically programmable signal propagation over the wireless medium [1], is the Reconfigurable Intelligent Surfaces (RISs) [2], [3]. Those planar structures typically consist of multiple metamaterial elements, whose ElectroMagnetic (EM) properties can be externally controlled in a nearly passive manner, allowing them to realize various reflection and scattering profiles [4].…”

“…The passive nature of RISs implies that they can only act as adjustable reflectors, thus, they can neither receive nor transmit their own data. While RISs enable smart programmable environments [1], their purely passive operation also induces notable challenges on the communicating entities. For instance, the introduction of an RIS implies that a signal transmitted from each User Terminal (UT) to the Base Station (BS) undergoes at least two channels: the UT-RIS and RIS-BS channels.…”

Arbitrary Beam Pattern Approximation via RISs with Measured Element Responses

“…They have several attractive properties that allow them to boost performance, without requiring installing and maintaining expensive base station (BS) infrastructure. While originally envisioned as a means to overcome line-of-sight (LoS) blockage and extend radio coverage, they have proven to be a versatile tool to control the wireless propagation environment, with applications to localization, radar and radio mapping, security, energy efficiency, and reduced electromagnetic field exposure [3], [4].…”