PHADE could be used by government agencies to enhance public safety; for example, the government can deploy cameras in high-crime or high-accident areas, and warn specific users about potential threats. PHADE also can be used in places such as museums, where visitors can receive messages with information about the artifacts or exhibits they are viewing. It could be implemented in shopping malls to provide consumers with digital product information or coupons.


City governments will be able to use PHADE to send alerts to distracted pedestrians when cars are approaching. (Purdue University)

PHADE technology allows public cameras to send personalized messages to people without compromising their privacy, a process called private human addressing. While traditional data transmission protocols need to first learn the destination's IP or MAC address, this system uses motion patterns as the address code for communication. The smartphones then locally make their own decisions on whether to accept a message. The PHADE system works using a server to receive video streams from cameras to track people. The camera builds a packet by linking a message to the address code and broadcasts the packet. Upon receiving the packet, a mobile device of each of the targets uses sensors to extract its owner's behavior and follow the same transformation to derive a second address code. If the second address code matches with the address code in the message, the mobile device automatically delivers the message to its owner. PHADE keeps the users’ personal sensing data within their smartphones, and transforms the raw features of the data to blur partial details. The creators named the system PHADE because the blurring process “fades” people's motion details out. PHADE has advantages over Bluetooth-based beacons, which have difficulties in adjusting for ranges of transmission, and do not allow for context-aware messaging.


Purdue University, West Lafayette, IN


Patents have been filed, and the Office of Technology Commercialization is seeking partners to license the PHADE technology.


The system allows surveillance cameras to “talk” to the public through individual smartphones; for example, it can be used to send alerts to distracted pedestrians when cars are approaching.