As shown in Figure 3, the nodes of the IndoorGML graph in this paper are considered the smallest organizational or structural units for the building and are called Cells [19]. Every Cell has an identifier (e.g., room number) and a location (x, y, z) to provide more precise location details. Cells are connected and have a common boundary with other cells but do not overlap with them. “Geometric” features and “Topological” relationships, such as adjacency and connectivity, amongst indoor cells can be defined by an IndoorGML graph [48]. The topological relationships in IndoorGML are explicitly described using the xlink concept of XML provided by Geography Markup Language (GML) and the referencing is realized with the use of href attributes (xlink:href). Semantics are also an important characteristic of the Cells in the IndoorGML. “Semantics” allow us to define cells which can be important for cleaning risk assessment. For example, the most commonly used areas are public rooms, corridors, and doors, and thus present higher risk. For this paper, an indoor space is represented as a topographic cellular space comprised of rooms, corridors, and stairs. At the same time, it is also represented as different cellular spaces with beacon or camera coverage Cells.