Headshot of Renjie Zhao.
Renjie Zhao

Renjie Zhao joins the Johns Hopkins University as an assistant professor of computer science. Zhao received his PhD in electrical and computer engineering at the University of California San Diego.

Tell us a little bit about your research.

My research focuses on wireless networking and mobile computing. I’m interested in designing and developing radical systems to support many emerging applications, such as 5G/6G cellular networks, the Internet of Things, smart homes, satellite communication, mobile health, etc. Based on my interests, I usually try to solve long-standing problems or enable new applications based on system approaches, which usually involve interdisciplinary fields, such as computer systems and networks, electrical engineering, and biomedical engineering.

Tell us about a project you are excited about.

I’m excited about most of my past projects, since they’ve addressed practical problems and have enabled applications that previously existed only in fiction. But among all of them, one direction I’d like to highlight is related to hyperscale IoT.

The vision of connecting everything in the physical world to the digital world requires hyperscale IoT networks consisting of trillions of IoT devices. However, the existing tethered or even battery-powered designs are not feasible for IoT at scale due to unaffordable maintenance costs and environmental hazards. Self-powered passive IoT is the ultimate means of attaining hyperscale IoT. With advances in radio-frequency integrated circuit fabrication, low-power communication, and wireless energy harvesting, we are now at an important juncture to explore system-level challenges of passive IoT.

My previous work has shown the potential of radical system architectures to approach extremely low power without overhauling existing infrastructure. My future research will further explore radical system architectures to build a fully passive IoT system for the next-generation hyperscale IoT network that is scalable, reliable, and multi-functional.

Why this? What drives your passion for your field?

I’ve always enjoyed hands-on experiences, particularly building things on my own. During my childhood, I was passionate about constructing fly models, tinkering with electronic devices, and avidly reading scientific magazines. The concept of IoT, which I stumbled upon in one of these magazines, fueled my imagination about a fully connected world. I was excited by the fully connected worlds in science fiction and movies even though there was only very limited internet access during that time.

As I navigated my choices for my undergraduate major, I found myself in the midst of a significant revolution in wireless networking that was reshaping humanity’s daily life and pushing the boundaries of technology. My curiosity led me to delve deeper into the requirements of building such seemingly “magical” electrical and wireless systems. To my delight, I discovered that my interests and strengths aligned seamlessly with this field, prompting me to initiate research in building ultra-low-power IoT systems.

I hold a strong belief that this field will be a driving force in revolutionizing our lives. The advent of hyperscale IoT will bring transformative changes to scientific research, industrial automation, and the very fabric of our daily existence, much like the impact of the rise of mobile devices.

What classes are you teaching?

I am teaching a graduate class on advanced IoT topics in the spring. The class explores the convergence of computer networks, mobile computing, and embedded systems, with a specific focus on IoT. It’s designed for graduate students who want to get in touch with the wireless IoT research frontier, which has opened up new possibilities, including mobile health, smart homes, industrial automation, and more.

I am also teaching Computer Networks in the Fall 2024 semester. Fundamental to any computing or intelligent system, the concepts of systems and networking underpin nearly every aspect of our lives, from business and health care to transportation and entertainment. This course is designed for undergraduate and graduate students to gain fundamental knowledge of computer networks, such as network architecture, protocols, and how computers interact with each other to support the connected world.

Why are you excited to be joining the Johns Hopkins Department of Computer Science?

Our department has a strong Systems & Networking Group that will be very helpful in my future research and development efforts; I love the wonderful collaborative environment and how everyone is so supportive and willing to help. Within the university, I’m able to easily find unique collaboration opportunities in other fields, such as biomedical applications. With all the talented researchers in the department, I’m excited to keep seeking out great ideas and having amazing discussions.

Besides your work, what are some of your other hobbies and passions?

I love cooking, playing video games, reading novels, and watching tech news. These hobbies help me refresh my mind, get entertained, and keep updated with the world’s advances.