Prototype development and test of a server-independent smart exit sign system: An algorithm, a hardware configuration, and its communication reliability

This study introduces the first working prototype of a server-independent smart exit sign system (SISES) and validates its communication reliability. A smart exit sign system (SES) is a new type of evacuation guidance system that changes the directions of exit signs toward safe paths. Thus far, only a handful of SESs have been proposed on a conceptual level and assumed that each sign node was controlled by a central server. They are, however, complex and expensive to install and vulnerable during a fire. To overcome these limitations, an SISES, which communicates over a wireless sensor network without a central server, was proposed. This study tests the communication reliability and speed of the SISES-the most critical factors for stable operation. The results show that the SISES can communicate reliably in various conditions and that it takes less than 4 s to update the entire system installed at a 3392 m2 building.