“…Other studies are dedicated to review the most common systems considered to detect occupancy in smart buildings [3,6,7,8,9] These works describe the fine-grained occupancy information in terms of spatial-temporal properties, such as presence, location, count, activity, identity, and track. In [6,7,9], most popular occupancy measurement techniques based on sensors, are described and compared. Authors of [3], classify the systems to obtain these properties in terms of: (i) the method, according to the need of wearable devices or based on passive sensors; (ii) the function, that classifies the systems in individualized system, if they have the capability of identifying and tracking individual building occupants, and non-individualized systems, if they only have the ability of providing occupancy information without user identity information or exact location in the building; and (iii) the infrastructure, that distinguishes the occupancy detection systems between explicit systems, whose unique purpose is to measure occupancy in the building, and implicit systems, which provide occupancy information along with another primary function.…”