# Sustainable and Reliable Information and Communication Technology for Resilient Smart Cities
## 9 Conclusions  
This paper summarizes a series of research studies relating to the systematic development of urban ICT and smart cities, which are based on the ongoing development and standardization activities conducted by Fraunhofer FOKUS. The core topic of this paper is given by the fundamental need to develop reliable and trustworthy ICT solutions and infrastructures for sustainable smart cities. Thereby, we started with a review of various related research and development activities, including long-term initiatives such as FIWARE or European projects such as Triangulum and Espresso. Afterwards, we laid the fundamentals for further discussions by defining the terms sustainability, smart cities and sustainable smart cities according to which we continued developing a set of relevant concepts on reliability and dependability. In order to systematically approach the topic of resilient and trustworthy urban ICT for sustainable smart cities, we introduced the concept of Open Urban Platforms and corresponding reference architecture models. With oupPLUS, we highlighted the quality assurance requirements for urban ICT, which are central for high quality reliable ICT infrastructure as a backbone for smart city processes. oupPLUS is discussed in detail towards the establishment of sophisticated quality assurance and certification processes for reliable and trustworthy urban ICT. Based on our practical experiences, we provided selected examples for methods and tools (e.g., test suites) and discuss--in relation to the reference architecture--current and upcoming technologies, which are important for smart cities. Based on our lessons learned in numerous practical smart city projects, we provide concrete recommendations for achieving reliable and trustworthy urban ICT and sustainable smart cities within the scope of the oupPLUS Open Urban Platform.  
With respect to future work: We are currently establishing further standardization activities within the German DIN Smart City Forum. These activities aim at standardizing the aspects of quality assurance and the various recommendations and related needs, setups and interrelations required to realize the recommendations (from Section 8) and to achieve better sustainable and resilient ICT-based smart cities. Furthermore, Fraunhofer FOKUS--together with industrial partners--has kick-started organizational and technical efforts to establish the discussed oupPLUS-based certification and recertification scheme.  
[PERSON] has made solid contributions during the past years to all related fields discussed in the current publication, especially to the areas and standardization activities for Open Urban Platforms and ICT reference architectures for smart cities. Furthermore, he is an expert in the domain of quality assurance and testing and hence his main contributions are related to Section 6, Section 7 as well as to the recommendations for reliable urban ICT in Section 8. Beyond that, [PERSON] contributed to shaping all the other sections of the paper. [PERSON] contributed to this research during her time as team leader and institute director at the Fraunhofer Institute for Open Communication Systems in Berlin. She was intensively involved in the discussion and standardization activities relating to the topics of Open Urban Platforms and design, engineering, and testing support for smart cities. In this regard, her main contributions are reflected in Section 5, Section 7 and especially in the introduction and definitions' parts of this paper, i.e., Sections 1 and 3. All authors have read and agreed to the published version of the manuscript.  
This work was partially funded by the projects Triangulum [26], Morgenstadt [35], STREETLIFE [24] and FI-WARE [29].  
Not applicable.  
The authors declare no conflict of interest.