While 6G networks are a nascent concept in 2021, corporations like Samsung and Nokia are already analyzing the potential hardware and software options required to make 2030 a target year for early commercialization.
Applications of 1G networks from the1980s to the proposed applications of 6G in 2030. Image used courtesy of Arxiv
6G Requires Unprecedented Throughput
The Internet of Things will be a significant driving force to develop the sixth-generation network infrastructure.
For the first time, machines will be the principal users of the network resources in “machine-to-machine (M2M) communication.” Secondary human users may use the expanded bandwidth for virtual/augmented reality, telepresence holography, and tactile control of robotics for high-precision tasks.
Today, 5G technologies rely on disaggregated network functions in the radio access network (RAN), edge computing, and virtualized network hardware to reduce cost and increase performance. These functions exist as trade-offs to each other to deliver the 5G network as it is now: enhanced mobile broadband, ultra-low latency communications, and M2M communications.
Visual of the design requirements for 6G. The 5G trade-offs requiring various RAN configurations are replaced by a heterogeneous online system. Image used courtesy of Samsung
However, for 6G to succeed, the trade-offs will need to be eliminated, allowing for a fully-connected, always-online world. This connectivity represents an exponential increase in RAN throughput and computes capability that isn’t accomplishable with discrete hardware/software functions.
A new spectrum is necessary to overcome these challenges, and engineers will need to develop accommodating hardware and metamaterials. Finally, AI and ML technology for 6G technologies will need to be “taught” and deployed in as few as nine years.
Pushing Microwave Frequencies to the Limits
In 2019 the FCC released the Spectrum Horizons Experimental Radio License to support the development of terahertz frequency communications technologies.
According to a group of researchers associated with the IEEE, terahertz frequencies are one contender for communication technologies applied to 6G, the other being visible light communications (VLC).
Once thought of as unusable frequencies, the terahertz bands may become a reality in the next decade. However, according to Samsung, major roadblocks exist in the propagation and reception of frequencies beyond 100 GHz, including:
- Path loss due to absorption and loss of line-of-sight (LoS)
- Electronics hardware dimensions, inducing losses in transmission, reception, and processing
- Advanced antenna lens and beamforming requirements to achieve LoS
- RF channel optimization, allocation, and the possible development of a replacement for orthogonal frequency-division multiplexing (OFDM)
LoS analysis of the various frequency bands operating today, both in practice and experimental. Image used courtesy of Arxiv
According to the IEEE research group, visible light communications will offer a cost-effective alternative to THz technologies by modulating LEDs and piggybacking on existing RF applications indoors to extend cellular coverage.
6G Requires New Hardware and Materials Research
Printed electronics may be key to the adoption of THz technologies, according to IDTechEx. These printed electronics would take the form of reconfigurable intelligent surfaces (RIS), measure only a few microns thick, and apply to many of the issues surrounding LoS communications.
A future metasurface structure steers the wave from an antenna in a more direct beam. Samsung believes RIS could replace antennas as well. Image used courtesy of Samsung
Metamaterials could address the issue of beamforming the signals for propagation to targets at various elevations on the ground, in the air, or around obstacles.
A high-level depiction of RIS. Developers will need to deploy RIS in high densities to overcome line-of-sight obstacles. This will re-broadcast or redirect signals to their target. Image used courtesy of Samsung
Network Requirements for Disaggregated Compute
Covering the generational shift to 6G, Peter Vetter (head of Nokia Bell Labs access and devices research) notes something of particular interest to hardware designers.
In a webinar, he explains that within the next 10 years, designers may see the advent of specialized hardware performing one function with limited onboard compute, aggregated into one application. This compatibility means that the network itself would be responsible for cloud edge processing and decision-making based on the increased hardware outputs.
Climbing the 6G Mountain Requires All Engineering Disciplines
To overcome the challenges associated with high-reliability, high-throughput 6G networks, engineers from all disciplines will need to work together. Hardware engineers will develop sensor and RF technology, AI/ML experts will develop self-optimizing networks, and computer engineers will create disaggregated compute capability.
Regulatory bodies such as the FCC will also play an essential role in protecting and allocating the spectrum required to facilitate this new digital domain.
5G may be here in 2021, but 6G development is accelerating already, and 2030 doesn’t seem so far away.
Featured image used courtesy of Samsung
Throughout your career, how have you seen RF design evolve to meet new network protocols? Let us know in the comments below.
