# A Comprehensive Survey on the Societal Aspects of Smart Cities
## 3 Smart Cities' Technologies
### Smart Cities Architectural Design
The aim of IoT-A is to transform these \"Intranet of Things\" implementations into true Internet of Things interconnected systems. This would enable different systems to connect seamlessly and to organically grow a smart city technological environment from various projects of various sizes and complexities, instead of needing to create it in a single instance. The IoT-A, completed  
Figure 3: Three-layer architecture. in 2013, would thus enable the gradual implementation of a smart city in any location as required [182]. The FIWARE framework is another project supported by the European Commission that aims to provide a platform that allows faster implementation and deployment of smart applications for various problems [183]. FIWARE is open-source and offers a marketplace of components that can be assembled with other third-party components, as well as data models to harmonize data input and output. This enables developers to accelerate development and deployment by allowing them to focus on the specifics of their solution and to use FIWARE components to support security, communications, or data analysis mechanisms [184]. Originally developed for research purposes, the platform is now available for businesses. While FIWARE is not without flaws (e.g., speed bottlenecks, scalability, or unavailable interfaces), one of its advantages is that new tools can be implemented and deployed to overcome those flaws [185; 186]. Examples of these tools are the results of the oneM2M project, a partnership between several countries that developed and promoted the oneM2M standard [187], a standard for interoperability for machine-to-machine (M2M) communications and IoT [188], whose reference implementation, the OpenMTC, optimizes the implementation of IoT applications. Moreover, OpenMTC is but one of the available alternatives. ACME, Eclipse OM2M, OCEAN Mobius, IoTDM, OASIS SI, and ATIS OS-IoT are all open-source implementations of oneM2M that a developer can use [189]. However, research in this area is ongoing since academia and industry continue to propose new architectures with different scopes, such as, for instance, an architecture for a smart city that is adaptable to the needs of each city [190] or the proof-of-concept implementation of the ISCO project of a framework for smart cities that relies on adaptative services based on smart objects [191]. In turn, there are other architectures that have been implemented in real cities, such as SmartSantander, which serves as a large-scale real environment testbed for not only new technologies in IoT and assesses how citizens make use of these technologies and what is their impact on their lives. SmartSantander is built upon WISEBED, SENSEI, and TELCO 2.0 components adapted to work together [192]. CitySDK was another architecture that was deployed in several cities for pilot testing. The deployment consisted of three application programming interfaces to support participation services, mobility data, and tourism information. The objective was to provide data standardization and open interfaces available anywhere in cities implementing the project [193]. These projects enable smart technologies to be implemented and tested in real-world environments and to serve as springboards for the implementation of fully fledged smart cities.