Fog mesh to the rescue when disaster strikes
Whether it’s a major earthquake, a Category 5 hurricane or some other natural disaster, the first piece of infrastructure to go down is generally the electrical grid. And when that happens, there’s no internet service in the stricken area. Cell service might still be available, but recent disasters have demonstrated that even where cell towers can deliver connectivity, they are quickly overwhelmed by demand as people check in with family members and try to organize assistance.
“One thing that happened with Hurricane Harvey was that there was no way to coordinate all of the people in Houston who wanted to help,” said Kishore Ramachandran, computer science professor at Georgia Tech. “There was no way of communicating with one another because of internet outages.”
Working with grants from the National Science Foundation and Microsoft, Ramachandran and colleagues are developing a way to use the computing power of smartphones, routers and other edge devices, such as roadside sensors, to create ad hoc networks that don’t rely on the internet. Specifically, Ramachandran’s team is working to build mesh networks that use devices as “fog nodes” that communicate with each other over alternative low-power transmission protocols, such as LoRa, that can be powered by the devices themselves.
The team is building a software architecture that has three components: a cloud-based management application, a data processing element placed in the fog infrastructure and a sensing component on the user's device.
According to Ramachandran, first responders arriving at a disaster scene would be able to locate potential victims by continuously pinging devices in the area and creating density maps that could then be used to prioritize rescue operations.
The capabilities go far being simply determining locations of devices, however. In the absence of internet connectivity, he said, first responders could also use the fog mesh “to share images, text, voice and so on -- to be able to do things that they would be able to do if there was connectivity to the internet.”
Even though first responders may have radio connectivity, Ramachandran explained, they still depend on internet connectivity for their situational awareness programs, which generally store data in the cloud. And even if their response apps can access that data in the wake of a disaster, there are still problems, particularly with regard to latency in data transmissions, he said. As the sensing infrastructure grows, which it is doing rapidly, Ramachandran said that relying on the cloud for data processing -- even when it is available -- may introduce delays that cost lives.
Edge computing -- pushing the processing of data from the cloud to devices connected to the fog mesh -- cuts response times. “We want to push the computation close to the edge of the network near the sensor sources so that we can do the processing quickly,” he said.
Apart from disaster scenarios, Ramachandran said that the team’s fog architecture can also benefit communities with limited or no internet access by providing connectivity among devices at the network's edge for public transportation management, job recruitment and housing. He envisions a bus equipped with fog network capabilities being sent to underserved areas to collect data -- from emails to job applications -- and uploading the information to cloud-based services when it returns to internet connectivity.
Posted by Patrick Marshall on Oct 18, 2017 at 7:28 AM