State-of-the-art information and communication technologies have become absolutely essential for all industries as the world is becoming more and more interconnected and data-driven. This trend has been further accelerated by the COVID pandemic. Where is the digital frontier today and what lies ahead? The annual MIT Information & Communication Technologies (ICT) event explores the latest research from across the Institute and its potential impact across industries. The webinar series will feature three sessions by six MIT faculty on the following topics: wireless communications, low power/edge computing and urban infrastructure. Additionally, a fourth session will feature MIT-connected startups presenting on the same topics.
ICT Webinar Series
Hari Balakrishnan is the Fujitsu Professor of Computer Science at MIT and a Director of MIT's Center for Wireless Networks and Mobile Computing. His research is in networked computer systems, with current interests in networking, sensing, and perception for sensor-equipped mobile devices connected to cloud or edge services running in datacenters. He has made many highly-cited contributions to mobile and sensor computing, Internet transport and routing, overlay networks and P2P systems, and data management.
In 2010, based on the CarTel project, Balakrishnan co-founded Cambridge Mobile Telematics, a company that uses mobile sensing, statistical methods, AI, and behavioral science to make roads safer by making drivers better. Over the past few years, CMT has become the world's largest telematics service provider, serving millions of users in 25 countries via partnerships with insurers, cellular carriers, rideshare companies, and automobile makers. He was an advisor to Meraki from its inception in 2006 to its acquisition by Cisco in 2012. In 2003, Balakrishnan co-founded StreamBase Systems (acquired by TIBCO), the first high-performance commercial stream processing (aka complex event processing) engine.
Balakrishnan received his PhD in 1998 from UC Berkeley and a BTech in 1993 from IIT Madras, which named him a distinguished alumnus in 2013. He was elected to the National Academy of Engineering in 2015 and to the American Academy of Arts and Sciences in 2017. His honors include the IEEE Kobayashi Computers and Commnications Award (2021), Fellow of the ACM (2008), Fellow of the IEEE (2020), Sloan Fellow (2002), and the ACM dissertation award (1998). He has received several best-paper awards including the IEEE Bennett paper prize (2004), and six "test of time" awards for papers with long-term impact from ACM SIGCOMM (2011), SIGOPS (2015), SIGMOD (2016), and SIGMOBILE (2017, 2018), and SenSys (2019). He has also been honored for excellence in research and teaching at MIT: the Harold E. Edgerton faculty achievement award (2003), the HKN best instructor award (2018), the Jamieson award (2012), the Junior Bose teaching award (2002), and the Spira teaching award (2001).
When radios communicate with each other, the transmitter spreads its signal in all directions. Hence only a small fraction of what is transmitted hits the receiver. Radios with multiple antennas can beamform, i.e., direct their signal so more of it reaches the receiver. How precisely a radio can beamform depends fundamentally on its size; a larger radio with more antennas can direct its signal better than smaller radios. Unfortunately, practical constraints on mobile and IoT devices prevent us from making radios large.
To address this challenge, we introduce RFocus. RFocus adds many thousands of antennas to the environment arranged as a 2D surface, where each antenna is a simple and inexpensive backscatter reflector similar to a passive RFID tag. They do not emit any signal of their own; instead they either reflect an incident signal or just pass it through. Each of these elements can be “on” or “off”, and the question is how to find the optimal state of each element so that the signal at any given receiver is maximized? This is a combinatorially explosive problem, but we have developed an elegant and practical approximation algorithm that works well. We have built a prototype of RFocus with 3200 elements, which may well be the largest number of antennas ever used for a single communication link! We show through real-world experiments that RFocus can improve received signal strength by a median of 10x in an office environment, and as high as 20x in challenging locations on an office floor. We will discuss applications to IoT, Wi-Fi, and 5G networks.
This is joint work with PhD student Venkat Arun.