Off the grid
Photo courtesy of Ayush Dusia | Photo illustration by Joy Smoker May 26, 2020
UD researchers advance communication options
Let’s say you are hiking the Adirondack Mountains in New York or the Rocky Mountains in Colorado. It is getting dark, you are miles from camp, and you sprain an ankle. You have no cell service. What do you do?
Or maybe you are dancing at a music festival with friends — say, Bonnaroo in Tennessee or Burning Man in Nevada. Among those hordes of people, it doesn’t take long to get separated from your group. But, because nearby cell towers are overwhelmed, there is no one you can call. What do you do?
Or perhaps you are riding out a hurricane in a coastal city. Water is flooding through your house, a tree has fallen on your car and — you guessed it — cell towers are down. What do you do?
Even in the United States, where connectivity is considered relatively decent, great swaths of the country still have spotty service … or none at all. Off-the-grid communication — which does not require pre-existing infrastructure such as the internet, cellular towers, Wi-Fi hotspots, or even satellites — can be a crucial and even lifesaving commodity. But, despite a wide-range of potential applications, it has never been mainstream.
Now, thanks partially to research involving scientists at the University of Delaware — an institution with a long history of innovative research on off-the-grid networks — that might be changing.
One of these scientists is Ayush Dusia, who earned a doctorate in computer science in December of 2019. His dissertation focused on the Mobile Ad hoc Network, or MANET. In such a system, there are no cell towers or satellites or internet routers. Instead, handheld devices relay messages directly to one another. They do so in a “multi-hop” manner, meaning when two devices aren’t within range, others in between relay — or hop — a signal from one to another until the message reaches its final destination.
There are challenges.
“The mobile devices in the network may move around and change the wireless connectivity,” Dusia said. Signals sometimes get dropped. Additionally, if the network is low-bandwidth, meaning it can’t handle too much data at once — say, the kind of network that operates on the same radio frequencies as a walkie talkie — it can easily be overwhelmed if too many signals are sent at once. This results in lost or dropped messages that need to be retransmitted, causing quicker battery drain.
As part of his dissertation research, Dusia completed an internship at goTenna, a Brooklyn-based company that sells devices for such off-grid, text-based messaging. At goTenna, Dusia joined a team led by Ram Ramanathan, UD graduate and chief goTenna scientist. Together, they worked on solutions for low-bandwidth, off-the-grid networks. The protocols they came up with result in fewer dropped signals and longer lasting batteries.
“This is significant,” said Adarshpal Sethi, professor in the Department of Computer and Information Sciences in the College of Engineering and Dusia’s doctoral adviser. “If you are in a disaster relief situation where conventional communication is broken, and the only available option is low-bandwidth, these protocols can still be used effectively.”
In addition to this work, Dusia also designed the first-of-its-kind infrastructure-less centralized architecture and routing protocols for MANETs. Translation: He figured out a way to have one designated device configure and program all other devices in the network. This means a centralized device serves as the traffic cop, keeping specific signal pathways from getting too jammed with messages during signal rush hour. The result? Fewer dropped messages.
Today, this centralized architecture is ready and waiting to go. The next step? For the business sector to adopt and scale it.
“It has huge potential in IoT (Internet of things) and the vehicular network space, as the world moves forward to Smart Cities and 5G connectivity,” Dusia said, meaning your self-driving car of the future might just depend on this. It is also conceivable that next-generation Androids or iPhones might come equipped with off-grid capabilities.
In the meantime, Dusia is working at VMware in Silicon Valley, where he is designing network virtualization solutions for data centers — improving wired instead of wireless networks.
But his time at UD? He said he’ll always look back on it with fondness and gratitude.
And — if you ever find yourself stranded at a crowded concert or on a remote mountaintop, still able to communicate — you likely will, too.