UC San Diego Celebrates 25 Years of Wireless Research Leadership
The University of California San Diego Center for Wireless Communications (CWC) is celebrating 25 years of partnering with industry to push the bounds of wireless technologies while training the wireless workforce of the future.
At the UC San Diego Center for Wireless Communication's 5G and Beyond Forum in November 2020, researchers from academia, industry and government presented on both 5G innovations and visions for 6G. The symposium also looked back at some of the Center’s impactful research and activities over the last three decades.
Looking forward, UC San Diego is engaging in national and international conversations focused on creating wireless research ecosystems and infrastructure through public-private partnerships that facilitate both innovation and workforce development. The general idea is to create scalable research ecosystems and infrastructure that can be accessed virtually and encourage development of future wireless technologies, use-case exploration for 6G and beyond, and the training of tomorrow's wireless workforce.
"I'm thrilled to be actively engaged with the Center for Wireless Communications, and all of our faculty, industry partners, and the wider wireless research community. We are working together to ensure that we have the wireless research infrastructure necessary to drive innovation and empower future generations of wireless engineers," said Albert P. Pisano, Dean of the UC San Diego Jacobs School of Engineering.
Wireless firms are already partnering with researchers at UC San Diego and elsewhere to create research infrastructure such as digital replicas of wireless networks. Building on this kind of shared, virtual research infrastructure will be crucial for collecting the data necessary to bring 6G-enabled technologies to fruition, explained Sujit Dey, who is an electrical and computer engineering professor at UC San Diego and Director of the Center for Wireless Communications.
“The Center for Wireless Communications has invested a lot of time into creating application-specific network testbeds -- we’re doing it for our smart transportation program for connected autonomous vehicles, as well as our connected health program for mixed-reality remote healthcare" said Dey. "We’re lucky to have industry partners that make this realistic, but it’s not possible for everyone to be doing this. I hope industry, academia and government can come together in creating digital replicas, digital twins, to not only have testbeds nationally, but to have these digital twins that replicate real situations and gather tremendous amounts of data we otherwise could not. For example with driving, we cannot drive unsafely. But with a digital twin you could get that data.”
Making transportation smarter
In addition to looking deep into the 6G future and beyond, researchers are also innovating and improving 5G connectivity. At the CWC Forum, UC San Diego engineers shared several research areas they’re focused on, including smart transportation and the hardware required to enable up to a trillion connected devices.
A session on connected and autonomous vehicles featured a number of projects at the UC San Diego Jacobs School of Engineering that are focused on improving how well self-driving cars can “see” and communicate with each other.
One example is a technology developed by the lab of UC San Diego electrical and computer engineering professor Dinesh Bharadia that could enable self-driving cars to navigate safely in bad weather. It consists of multiple radar sensors working together like multiple eyes to create a fuller view of the road, even when it’s not clear outside. The setup can accurately predict the dimensions of a car moving in fog. Bharadia is working with Toyota and Honda for further research and development. He says this new technology could provide a cheap alternative to lidar.
Improving self-driving cars’ vision will also require reconciling images taken by sensors at different viewpoints. A camera from a vehicle and a camera from a lamp post, for example, can both see the same object, but they might not know it is the same because they are viewing it from different angles, said Truong Nguyen, a professor of electrical and computer engineering at UC San Diego. To address this issue, Nguyen and his lab developed algorithms that can find features that are common between these pictures and match them to objects. The algorithms work in both 2D images and 3D point clouds. The researchers are currently optimizing the algorithms for real-time computation.
As more cars and streets become outfitted with cameras and sensors, an emerging opportunity and challenge will be fusing live data from all of these different sources, obtaining intelligent perception of the environment, and sharing the insights with all the vehicles and even other road users like pedestrians and bicyclists.
Sujit Dey, the Center for Wireless Communications director, is working with CWC colleagues and industry partners to develop intelligent roadside units to perform these tasks. The idea is that vehicles—both autonomous and human-driven—would send data from on-board cameras, radar and lidar sensors to the roadside units, which would fuse and process the data, and then provide enhanced perception to vehicles and other road users to improve advanced driver assistance systems, and to autonomous vehicles for more efficient path planning and navigation. Because all of this hefty computer processing will consume a lot of power, Dey and colleagues are building units that are powered by renewable energy so they can reduce their carbon footprint.
Connected vehicle technologies will also require high-throughput data rates. Millimeter wave directional beams can accommodate these increases in data use, but the problem is they are susceptible to blockage from buildings and human bodies. They are also hard to manage when tracking moving objects.
UC San Diego electrical and computer engineering professor Xinyu Zhang is exploring ways to make millimeter wave technology practical for connected vehicle applications. His lab built a testbed at the UC San Diego campus to explore the feasibility and challenges of millimeter wave-connected vehicles. The researchers discovered that millimeter waves can boost link speed by orders of magnitude in best case scenarios, but this requires deploying a significantly large number of base stations on site. The good news, Zhang noted, is that since road segments have simple geometries, base stations can easily “spot-light” on vehicles using their directional beams to maintain connectivity. The researchers are exploring machine learning algorithms that can make the base stations intelligent enough to harness such advantages.
Circuits for a more connected world
The future will experience an explosive growth in the number of connected devices being used worldwide. By 2035, we can expect that number to be a trillion, said UC San Diego electrical and computer engineering professor Patrick Mercier.
But to get to that number, engineers need to figure out how to improve the power management of these devices, he noted. The battery life of a typical IoT device ranges from a few hours to a few days. The largest fraction of that battery power is being spent by the radio subsystems.
|By only waking up a wireless device when necessary, the wake-up receiver (chip stack to the left of the penny) can cut down on power use and extend battery life. The system includes a miniaturized antenna (gold-colored plate below the receiver). Photos by David Baillot/UC San Diego Jacobs School of Engineering|
Mercier’s lab is working on solving this power problem by buildingultra-low power wake-up radios. As their name implies, these radios wake up a device only when it needs to communicate and perform its function. This allows the device to stay dormant the rest of the time and reduce power use. The latest wake-up radio from the Mercier lab boasts a power consumption of 4.4 microwatts and is compatible with both WiFi and Bluetooth. Mercier says the technology could improve the battery life of small IoT devices from months to years.
A number of UC San Diego electrical engineering professors are at the cutting edge of building hardware elements for next generation 5G systems. These include power amplifiers with highly efficient supply modulators (Peter Asbeck and Hanh-Phuc Le); phased arrays that transmit and receive over a wide band (Gabriel Rebeiz); and digital phase-locked loops with state-of-the-art performance (Ian Galton).
While 5G connectivity is still being rolled out and improved for users around the globe, wireless industry and academic leaders are already exploring what the next generation of connectivity—6G—will look like, and starting the research required to enable it.
A panel of experts from Samsung Research, Qualcomm, Nokia, Ericsson and UC San Diego agreed that the specific technical capabilities of 6G are still being hashed out, but some rough estimates do exist.
While 5G connectivity in 2021 is expected to have speeds of 100 gigabits per second and latency of 500 microseconds, 6G connectivity is expected to increase the speed of transmission to 1 terabyte per second, with latency as low as 100 microseconds.
Use cases for these high data rates and low latency include truly immersive extended reality experiences, as well as mobile holograms and "digital twins" which refers to recreating physical entities in a virtual world to study, alter and interact with them.
The panelists also agreed that they expect 6G connectivity should be entering the wireless market within the next 10 years, perhaps as early as 2028. What research is required from academic researchers to enable these speed and latency improvements?
On the semiconductor side, improving radio-frequency integrated circuits (RFICs) to function at terahertz bandwidth will be key. In addition to moving into terahertz bandwidth, research into dynamic spectrum sharing options is needed.
“The wireless industry is incredibly grateful for the existence of the Center for Wireless Communications,” said Martha Dennis, a technologist, venture capitalist and a member of the CWC’s founding executive council at the recent CWC 25th anniversary forum. Over the center’s 25 year lifespan, more than 40 companies have become members.
As wireless technologies are incorporated into more and more industries, services and products, the number and diversity of companies partnering with CWC is sure to rise.
Jacobs School of Engineering