5G and ECE: Connecting the world

5G, with its combination of ultra-low latency, high speed, high reliability, high capacity, and potential for ubiquitous use, will usher in a multitude of highly anticipated applications, while dramatically improving the functionality of existing wireless services. It is a technology built on the work of electrical and computer engineers, and reliant on ECE research to fulfill its promise.

According to a recent report, the impact of 5G on global economic growth is expected to tip $13.2 trillion by 2035. Its use so widespread as to put it in the same category of general purpose technologies as the printing press, electricity, the automobile, and the Internet.

The United States is committed to expediting 5G though the FCC’s 5G FAST Plan, which includes a proposed $9B 5G fund to bring the most advanced wireless services to under-served rural America. 

Some of the most anticipated applications impacted by 5G include a truly massive Internet of Things; improved control and automation in manufacturing, energy, robotics, and autonomous vehicles; highly precise location tracking for traffic safety and asset management; and remote healthcare. The new 5G will also be a key enabler of “smart” homes, cities, agriculture, energy, and grid. And for the average user – it will enable a more seamless experience for those trying to communicate with others remotely, especially when incorporating video and including the exchange of data-rich files.

This will all take time, and there’s plenty of work to do in order to take advantage of the possibilities inherent in 5G, the fifth generation technology standard for broadband cellular networks.

Electrical and computer engineers will be applying their expertise in electronics, electromagnetics, antennas, chip design, control, signal processing, radio-frequency engineering, cyber-physical systems, telecommunications, and more, to optimize devices and build algorithms needed to exploit the potential inherent in 5G technology.

Here are a few current research projects related to 5G technology happening here at Michigan.

Massive IoT – Autonomous Driving

With 5G capable of connecting 1 million devices per square kilometer, we are building sensors and computers that are compatible with this new Massive IoT. For example, Prof. Hun-Seok Kim is developing a new type of VLSI system-on-chip (SoC) that combines the adaptability of general-purpose processors with the efficiency of a specialized baseband modem integrated circuit. This hybrid system will be suitable for demanding 5G wireless applications that range from swarms of IoT sensor devices to autonomous vehicles and devices. It could also allow for a 5G wireless communication design that adapts to different environments through changes in software.

In the area of antenna design, Prof. Kamal Sarabandi and his team are developing a full-duplex antenna that can potentially provide services for twice as many users as that of current cellular networks. This antenna system has a wide range of applications, including autonomous vehicles, remote sensing, and biomedical imaging.

Sarabandi is also developing technology for vehicle-to-everything (V2X) communication to take advantage of the highest 5G speeds available at the millimeter-wave spectrum. With this technology, autonomous vehicles can connect to the cloud and access local information like point cloud of obstacles for precise geolocation and situational awareness, sharing intent and sensor data to adjacent vehicles and pedestrians, etc. The result will be higher levels of safety for autonomous driving.

5G presents an entire new set of challenges to the design of mobile devices. To support many wireless technologies (such as Wi-Fi, Bluetooth, GPS, 3G, 4G, etc.), today’s mobile devices already contain a significant number of RF switches and badpass filters to set the device operating frequency. 5G will only continue to increase the number of communication frequency bands and accordingly the number of filters and switches, which will increase the circuit size, complexity, and cost.

Prof. Amir Mortazawi and his group are looking to better support 5G by creating a new class of reconfigurable radio frequency (RF) acoustic devices that are only tens of micrometers in size – or the width of a human hair. Working with Mortazawi, doctoral student Milad Zolfagharloo Koohi pioneered a way to combine switching and filtering functionalities onto a single device.

“[We are] laying the ground for the upcoming 5G technology and allowing the next generation of communication devices to be much faster and cheaper,” said Koohi.

Michigan’s Mcity, the advanced mobility research center featuring 16 acres of roads and traffic infrastructure, now has a 5G ultra wideband network.

Prof. Necmiye Ozay is developing formal methods for driving safety, where one of the goals is to understand to what extent 5G (or other communication schemes with different range and bandwidth properties) can improve safety. One goal of the project is to lengthen the time that a car can predict its driving path, and share this information with surrounding vehicles. She will be testing new algorithms being developed for highway safety at Mcity.

Edge Computing

5G is expected to dramatically increase the demand for computing at the edge of a wireless network, so-called edge computing, rather than sending all of the data to a cloud server. It is critical for autonomous and semi-autonomous driving and other mission critical applications.

To facilitate edge computing, Prof. Robert Dick is developing highly heterogeneous, low-rate approaches to data capture, thereby reducing data transfer (and analysis) requirements with little impact on decision quality. The approach uses a biologically inspired, multi-round process to guide later captures based on observations in earlier captures.

Similarly, Prof. Vijay Subramanian and colleagues are investigating how machine learning techniques can help better optimize network operations for improved wireless service.

Impact on the Grid

5G will facilitate efforts to control both traditional power system generating resources and distributed energy resources, which will in turn improve the flexibility, reliability, and economics of the nation’s grid. Profs. Johanna Mathieu and Ian Hiskens are conducting significant research in this area, while partnering with industry and other institutions.

One project is addressing the electric load control problem, in which the goal is to coordinate the power consumption of thousands of small electric loads like air conditioners and refrigerators to help the grid balance supply and demand without inconveniencing electricity consumers and while respecting the physical limitations of the power distribution network. This will ultimately support the integration of more wind and solar power on the nation’s grid.

Hiskens and Mathieu are also investigating the limitations and physical issues that arise using typical communication networks to coordinate flexible loads. And they will be developing control strategies to overcome those issues, many of which could significantly change with high fidelity 5G networks.

Bringing 5G to Rural Areas

Professor Vijay Subramanian is leading a project to respond to the nation’s call for pervasive 5G in sparsely populated areas. The problem is that companies feel it’s not cost effective to install the same coverage in rural, or even some suburban, areas as in urban areas. To help solve this problem, his team, that includes Profs. Kamal Sarabandi and Robert Dick, is developing a hybrid powerline/wireless architecture that uses existing infrastructure as well as low-power wide area networking (LPWAN) protocols to bring 5G to homes, schools, and even buses in the Upper Peninsula.

First Digital Single-chip Millimeter-wave Beamformer Will Exploit 5G Capabilities

The first fully-integrated single-chip digital millimeter-wave (MMW) beamformer, created by Prof. Michael Flynn and his team, opens up new possibilities in high-frequency 5G communications. The technology could be used to improve vehicle-to-vehicle communication, autonomous driving, satellite internet, and national defense, to name a few.

Beamforming allows a device that is transmitting signals to point them in a particular direction, as opposed to having the signals radiate out in all directions – which can lead to significant interference and loss of efficiency. It is an essential technique for MMW communication, which occurs at a relatively high frequency (typically between 24GHz and 100GHz). This high frequency communication allows for high-speed data transfer, one of the key advantages of 5G.

Analog beamforming has been a standard approach for researchers, but Flynn has been investigating a digital approach to exploit advantages such as large-scale beamforming, highly accurate beam-patterns, flexibility, and the ability to generate multiple beams simultaneously.

“With analog beamforming, you can only listen to one thing at a time,” said Flynn. “But there are a number of new applications where you want to listen to multiple things at the same time, and switch quickly between them.”

For example, Flynn can imagine using digital beamforming on drones sent into disaster areas to provide emergency Internet to people in trouble. Similarly, there are plans to launch satellites in space in order to provide connectivity to people who live outside cities, where access to the Internet can be spotty or non-existent. Having phones with digital wireless beamforming capability would provide individuals with more reliable access to the Internet.

Flynn and his group built a 28GHz MMW digital beamformer, with a custom-designed antenna array consisting of 16 antennas in single integrated circuit. It is the first known single-chip system to do MMW digital beamforming. In part because it’s a single chip, the power and size are better than current digital systems by an order of magnitude. And because it’s digital, the signal can both be pointed in any direction, and can “listen” in from four different directions at once.

“People never stop chasing for better and better connectivity,” said doctoral student Lu, who received a best student paper award for the research. “Millimeter-wave digital beamforming may be a gamechanger in the world of 5G.”

Commercializing Technology to Take 5G to the Next Level

Two ECE postdoctoral researchers and alumni are steadily building their young company, SkyGig, to bring the next generation of high-speed wireless connectivity to the 5G ecosystem, satellite communications (Satcom), and beyond.

After earning first place and $75K in the ECE Innovator Program in 2018, being awarded a Michigan Translational Research and Commercialization (MTRAC) grant in 2018-19, and founding SkyGig in 2019, Dr. Armin Jam and Dr. Avish Kosari have been recognized by various awards and programs with more than $1M in funding sponsored by NSF, NASA, and Activate, among others.

They are now expanding their team to accelerate development and commercialization of their disruptive technology.

“Millimeter-wave (mmWave) technology is at the frontier of wireless communications, and as such, still provides significant challenges,” said Jam. “At SkyGig, we are targeting the higher portion of the radio frequency spectrum, referred to as the millimeter-wave band, with key applications in 5G, SatCom, and automotive radar, among other emerging markets.”

Jam and Kosari aim to lead in this area by bringing innovative holistic approaches to mmWave transceiver technologies through their combined expertise in electromagnetics and antennas, and RF integrated circuits, respectively.

6G and Beyond

Looking beyond 5G, Prof. Ehsan Afshari is pushing the existing boundaries in high frequency communication by combining novel circuit topologies and efficient systems. He is currently involved in a project to design and implement a fully integrated communication link at 220GHz that can support data rate of 60Gbps, which is 3x that of 5G. This is at a distance of 10m, but the proposed system can easily be modified for longer distances (>100m) with either lower data rate (below 20Gbps), or the same data rate but using off-chip high gain antenna arrays on the printed circuit board.

Among Afshari team’s accomplishments are the highest effective isotropic radiated power among all radiators above 200 GHz, a 220GHz radio with 24Gbps data rate at a distance of 1m, the highest output power among all integrated circuit sources at and above ~500 GHz, the first fully integrated THz phased array on silicon, the first coherent THz imaging system on silicon, and the first fully integrated >100 GHz FMCW radar on silicon.

In summary, 5G is poised to become a technology that will drive the economy and dramatically impact virtually every aspect of modern society – with ECE right in the center of the action.