Wireless broadband from lamps

​Chalmers Jubilee Professor Maïté Brandt-Pearce gives her vision of how indoor lighting could in the future provide us with wireless data connectivity.

Maïté Brandt-Pearce, from the University of Virginia, is one of four Chalmers Jubilee Visiting Professors this year. Her research includes both fiber optic and wireless optical communications.  These technologies have the potential of providing tremendous throughput, on the order of tens or hundreds of Gbps per user. The challenge lies in how to design systems and networks to exploit this promised capacity.
“One project I am currently excited about considers using the indoor lighting system as a means of communications, thus providing illumination and data connectivity simultaneously. Currently 80% of wireless data transmission occurs indoor, yet our indoor communications systems are woefully limited, says Professor Maïté Brandt-Pearce.
About 50% of our data needs today are from video, a type of data that is demanding in terms of bandwidth, signal quality, and latency.
“Imagine a classroom with 40 high schoolers all simultaneously prepping their multimedia presentations, or a plenary talk where half the audience in the hotel ballroom opts to check news videos instead of minding the speaker -- current Wi-Fi systems slow to a crawl in such scenarios, to the frustration of conference attendees, students, and teachers alike. “
Visible light communications offers the possibility to match wired data speeds, even in demanding environments such as these, as well as shopping malls, airplanes, hospitals, etc.
“The benefits of this so-called visible light communications include energy savings, high throughput, privacy, and immunity to electromagnetic interference. It is a clever way of circumventing bandwidth limitations of the current Wi-Fi technology.”
Smarter wired networks needed within five years
Our fiber optic networks are experiencing a similar problem of resource shortage. 
Professor Maïté Brandt-Pearce“Unbeknownst to most of us, we use long-haul fiber networks every day: for video downloads, email, VoIP, etc.  Fiber throughputs have been following Moore’s Law, doubling every 9 months or so; but the physical limit is in sight, and that limit means demand for transmission outpacing supply, which inevitably leads to higher costs. Current fiber infrastructure will be stressed to its limit within five years, so we must act quickly to develop new technologies to make better use of our resources.”
When fibers are assembled into large (continental-scale) networks, assumptions of perfect transmission quality used in metro-scale networks begin to fail, and smarter network management techniques are needed. Long-haul transmissions experience linear and nonlinear impairments that must be avoided or mitigated. 
“This problem is hugely important because without solutions that increase network utilization, the current fiber infrastructure will have to be expanded very soon, and that will be very expensive.”
“Today’s network management protocols expect usages around 10%:  by developing better networking algorithms, and accelerating the development of more efficient point-to-point links, we have a chance of staving off the inevitable high-cost infrastructure upgrade.”
Four months at Chalmers
During her four months Jubilee professorship at Chalmers, Maïté Brandt-Pearce will collaborate with researchers in the departments of Signals and Systems and Microtechnology and Nanoscience, particularly those interested in optical communications, such as Erik Agrell and Magnus Karlsson.
“Our work is highly complementary, and we have plans to work on combating nonlinear fiber impairments in particular.  I also enjoy discussions with PhD students on their research topics: Chalmers has outstanding students, and I find their energy and creativity contagious.”
Do you have other hopes or plans for your stay in Gothenburg?
“One of the exciting aspects of travelling is getting to learn about other people and their culture. I am looking forward to making Swedish friends, learning about the history, admiring the natural beauty, and tasting the local food. I had also hoped to learn how to cross-country ski, but it seems that spring has come early this year. I will have to come back another time!”
Text: Malin Ulfvarson
On March 20, 2014, Professor Maïté Brandt-Pearce is holding a seminar entitled “Wireless Connectivity through Lighting
Chalmers Jubilee Professorship
When Chalmers in 1979 celebrated 150 years, the government gave a Jubilee Professorship at Chalmers as a gift. The criteria to be met are that the holders will add Chalmers new skills and that the University's international relations will be strengthened.


Maïté Brandt-Pearce biography
Dr. Maïté Brandt-Pearce received her Ph.D. in Electrical Engineering from Rice University in 1993. She then joined the Charles L. Brown Department of Electrical and Computer Engineering at the University of Virginia, where she is currently a full Professor. Her research interests include nonlinear effects in fiber-optics, free-space optical communications, optical networks subject to physical layer degradations, body area networks, and radar signal processing. Dr. Brandt-Pearce is the recipient of an NSF CAREER Award and an NSF RIA. She is a co-recipient of Best Paper Awards at ICC 2006 and GLOBECOM 2012. She serves on the editorial board of IEEE Communications Letters, IEEE/OSA Journal of Optical Communications and Networks, and Springer Photonic Network Communications. She is co-editor of a book entitled Cross-Layer Design in Optical Networks, Springer Optical Networks Series, 2013. Dr. Brandt-Pearce has over a hundred and fifty major journal and conference publications.

Published: Fri 07 Mar 2014.