# Smart Cities of the Future as Cyber Physical Systems: Challenges and Enabling Technologies
## 5 A Holistic Approach toward Next Generation Smart Cities Application Management
### Infrastructure Management  
Infrastructure management regards both the management of the network and computational resources that are required for the provision of the various IoT application parts, as well as the management of the deployed IoT devices at the edge part of the infrastructure. We provide details per category regarding resource management. Network, computer, and storage resource management has to be provided based on the needs of each IoT application to guarantee the optimal usage of the available resources, while providing the required QoS levels. In the case of 5G environments, by considering the set of IoT applications requirements, a context-aware IoT slice has to be created and managed. Each IoT slice is going to be instantiated, given the request for the deployment of an IoT application. The main types of the considered slices regard IoT services are classified as massive Machine Type Communication (mMTC) services and URLLC services. mMTC relates to a very large number of devices transmitting a relatively low volume of non-delay-sensitive data (leading to the creation of a Massive IoT Slice), and URLLC relates to services with stringent requirements for capabilities, such as throughput, latency, and availability. The IoT network slice is realized and managed on behalf of a telecom operator through the deployed orchestration (e.g., the Network Function Virtualization Orchestrator--NFVO) components and network management systems. Following evolving 3 GPP specifications, the mechanisms that manage the IoT application network slice are responsible for realizing the setup of virtual (isolated/shared) 5G networks built upon the combination of standard Network Functions, such as the User-Plane Function (UPF), the Session Management Function (SMF), and the Network Exposure Function (NEF), etc. Cloud and edge computing resource management concerns the reservation of the required computational and storage resources at the cloud and edge part of the infrastructure. Multiple edge locations and edge clusters are considered, with the continuous interplay of resource management mechanisms between cloud and edge resources as well as among edge resources. Interfaces toward Virtual Infrastructure Managers (VIMs) and computer resource clusters allow the reservation of resources and to create tenant spaces for hosting IoT application components and VNFs at edge computing facilities. Computer offloading mechanisms can be supported for deploying workloads closer to users and IoT devices, and properly scheduling the execution of resource-intensive tasks. Management of IoT devices can be realized in two ways; through management of their virtual counterpart (digital twin) or through management mechanisms applied by IoT agents in the IoT devices. In the first case, the developed software components are considered as an extension of the IoT application graph and can be managed by the developed orchestration mechanisms, while, in the latter case, interfaces for the management of IoT devices are made available. In both cases, proper abstractions for the supporting management of the IoT devices represented based on different semantic models have to be provided. Focus has to be given to techniques that enable semantic interoperability even if different information models are used. To achieve this, alignment with well-defined information models (e.g., the FIWARE data model and W3C Web of Things) has to take place, considering the IoT node capabilities, communication protocols, and type of the sensed context. Adoption of the provided solutions by humans, through the support of interactiosn with real and virtual devices, exploiting advancements in AR/VR technologies, is considered as crucial. Given that tactile interaction refers to a level of responsiveness that works at a human scale, the combination of efficient deployment and provision of IoT applications with effective, usually synchronous, and human-friendly interaction among humans and IoT devices has to be supported.