ITU‐T's Technical Reports and Specifications 365 Figure 10 – A multi‐tier SSC ICT architecture from communications view, emphasizing on an information flow perspective There are two ways for the information flow in the above architectural view: 1. The information flow starts from the sensing layer to the application layer across the communication layer and the data layer. This is the most typical mode of information flow in SSC, as it involves the whole four layers of SSC. 2. The information flow starts at the sensing layer and terminates at the data layer directly without across the communication layer, or start at the sensing layer end at the application layer directly without across the communication layer and the data layer. 7.1.3 Modular SSC ICT architecture approach Module definition for the SSC ICT architecture is an extremely complex process and it has to consider both the city type and the architecture view. According to the previously given analysis, soft urban infrastructure (people, data and applications) is flexible and can easily extend and interconnect. Difficulties rise from requirements, which deal with hard infrastructure and environment. Various attempts illustrate modular smart city approaches [8; 9; 10]. Moreover, an interesting modular Cyber‐security users layer end‐users (demand side: i.e., inhabitants)end‐users (supply side: i.e., stakeholders' representatives)presentations layer applications layer (software applications offering SSC services)Transportation, E‐government, E‐business, Safety and Emergency, Smart health, Tourism, Education, Smart Building, Waste management , Smart Energy, Smart water business layer (business processes that simulate service logic)Communications Network layer Transport network (SDH, DWDM, IP, Microwave etc.)Access network (xDSL, FTTx, WiFi, 2G/3G/4G, PLC etc.)data layer Data repositories File repositories sensing layer Capillary Network (SCADA, sensor network, HART, WPAN, video surveillance, RFID, Barcode, GPS, etc.Terminal node (sensor, transducer, actuator, camera, RFID tag, barcode symbols etc.