1105 CONCLUSION ITU aims to assist urban administrations in their journey towards becoming “smart” and “sustainable”. ITU’s work to build greater understanding of the functionality of Smart Sustainable Cities is an essential part of this assistance. A Smart Sustainable City is an intricate, multi-layered system. An urban administration’s commitment to develop a Smart Sustainable City should be supported by an in-depth understanding of their composition and functionality. This in-depth understanding is crucial to the formulation of a long-term vision for the development of a Smart Sustainable City, as well as a strategy to guide stakeholders towards the realization of that vision. This compendium will help urban administrations to gain the in-depth understanding necessary to the formulation of a vision and supporting strategy for the development of a Smart Sustainable City. ITU has also strengthened its commitment to assist cities in their transformations into Smart Sustainable Cities by ofering them the required support on a city-by-city basis.It is ITU’s hope that this compendium of Technical Reports and Specifications will help cities to commence their transformations into Smart Sustainable Cities, and we encourage all smart-city stakeholders to follow or participate in the work of ITU-T Study Group 20, a group with considerable influence in shaping technical priorities for Smart Sustainable Cities. ITU-T’s Technical Reports and Specifications 6