Space-time-coding metasurface could transform wireless networks with dual-functionality for 6G era

Amazing stuff!

"... Researchers ... showed that a specific PM, known as a space-and-time-coding metasurface, could simultaneously support both sensing and wireless communication.

Their paper ... introduces two promising schemes for integrated sensing and communication (ISAC) that rely on a space-and-time-coding metasurface they developed. ...

Notably, the metasurface designed by Cui and his colleagues supports both the original frequency of a signal it is interacting with and additional harmonic frequencies, which can be controlled with high precision.

While the original frequency can be used to enable high-quality communication, the controllable harmonics support the real-time sensing of the surrounding environment and the detection of signals of interest via a machine-learning algorithm. ..."

From the abstract:

"Programmable metasurfaces (PMs), also called reconfigurable intelligent surfaces (RISs), are planar structures capable of dynamically manipulating electromagnetic waves in real-time. Regarded as a key enabling technology for implementing smart wireless propagation environments, PMs/RISs also serve as an ideal supporting platform for integrated sensing and communication (ISAC). Here, we propose two ISAC schemes based on a special type of PMs/RISs: space-time-coding metasurfaces (STCMs). By leveraging space-time-coding strategies, STCMs simultaneously control the propagation at the fundamental (carrier) frequency for reliable wireless communication and generate spatially distributed harmonics for sensing. The proposed schemes seamlessly integrate both communication and sensing on a shared hardware platform, eliminating the need for additional sensors. For experimental validation, we implemented an ISAC system using a 2-bit STCM operating at microwave frequencies. Experimental results align with theoretical predictions, confirming the practical viability and effectiveness of the proposed ISAC schemes for applications in communication, imaging, radar, and sensing systems."

Space-time-coding metasurface could transform wireless networks with dual-functionality for 6G era

Integrated sensing and communication based on space-time-coding metasurfaces (open access)

Fig. 1: Conceptual illustration of the proposed space-time-coding metasurface (STCM)-based integrated sensing and communication (ISAC) scheme.

5G Networks Meet Consumer Needs as Mobile Data Growth Slows. It’s Time To Rethink 6G

Food for thought! Will new applications etc. be developed that need more bandwidth?

Caveat: I did not read the whole article!

"Is the worldwide race to keep expanding mobile bandwidth a fool’s errand? Could maximum data speeds—on mobile devices, at home, at work—be approaching “fast enough” for most people for most purposes?

These heretical questions are worth asking, because industry bandwidth tracking data has lately been revealing something surprising: Terrestrial and mobile-data growth is slowing down. In fact, absent a dramatic change in consumer tech and broadband usage patterns, data-rate demand appears set to top out below 1 billion bits per second (1 gigabit per second) in just a few years. ...

Transmitting high-end 4K video today requires 15 Mb/s, according to Netflix. Home broadband upgrades from, say, hundreds of Mb/s to 1,000 Mb/s (or 1 Gb/s) typically make little to no noticeable difference for the average end user. Likewise, for those with good 4G connectivity, 5G makes much less of an improvement on the mobile experience than advertisers like to claim—despite 5G networks being, according to Cisco, 1.4 to 14 times as fast as 4G.

So, broadly, for a typical mobile device today, going much above 15 Mb/s borders on pointless. For a home, assuming two or three inhabitants all separately browsing or watching, somewhere between 100 Mb/s and 1 Gb/s marks the approximate saturation point beyond which further improvements become less and less noticeable, for most use cases. ..."

5G Networks Meet Consumer Needs as Mobile Data Growth Slows - IEEE Spectrum

Reducing delays in wireless networks with better congestion control

Good news! It's a mundane subject, but with great importance to our daily experience of using wireless networks.

" ... wireless networks, which have “time-varying links,” with rapid, unpredictable capacity shifts. Depending on various factors, such as the number of network users, cell tower locations, and even surrounding buildings, capacities can double or drop to zero within fractions of a second. In a paper ... the researchers presented “Accel-Brake Control” (ABC), a simple scheme that achieves about 50 percent higher throughput, and about half the network delays, on time-varying links. ... "


Reducing delays in wireless networks | MIT News: Researchers at MIT’s Computer Science and Artificial Intelligence Laboratory have designed a congestion-control scheme for time-varying wireless links, such as cellular networks, which reduces lag times and increases quality in video streaming, video chat, mobile gaming, and other web services.