The High-Frequency Generator is a device created by Wayne Enterprises R&D department inspired by Lucius Fox’s sonar mapping technology. The device turns every cell phone in Gotham into a microphone and high- frequency receiver. The cell phones in the city use sonar to feed the main computer information mapping the city of Gotham. Bruce Wayne had the R&D department developed a device as a tool to triangulate the Joker’s location. The database is null-key encrypted and it can only be by Lucius Fox and without the program to self-destruct after he entered his name into it.