ITU‐T's Technical Reports and Specifications 141 1 Introduction Within an increasingly inter‐connected world, rapid urbanization constitutes one of the most challenging facets of the 21st century. 54% of the world's population resides in urban areas, a percentage that is expected to reach 66% by 20502. The growth of the world's urban population is evidencing the need to re‐think traditional approaches to sustainable development and urban planning, in both developed and developing countries. During the period between 1950‐2010, small cities have grown in population (1.3 billion) much more than medium cities (632 million) or large cities (570 million)3. According to the United Nations Population Fund (UNFPA), in 2007, for the first time in the history, people living in cities were more than those in rural areas4. Due to migration flows, the natural population growth and certain policies, among other factors, urban areas are becoming more congested. Rapid urbanization is adding pressure to the existing resource base, while increasing the demand for energy, water, sanitation, and public services such as education and health care. In parallel to the rising demand for services, cities are developing into vast consumers of energy and major producers of greenhouse gas (GHG) emissions, and have been estimated to represent three quarters of the global energy consumption and 80% of CO2 emissions worldwide5. In order to meet the growing needs and the opportunities associated with an increasing urban population, cities require innovative approaches to achieve sustainable development. This involves an improvement in the efficiency of all aspects of a city's operation (e.g., public services, construction, transportation), which are crucial to ensure more inclusive development pathways, and a higher quality of life (QoL) for its inhabitants. Smart Sustainable Cites (SSC) are key enablers for the achievement of these goals. Despite the recent emergence of SSC initiatives around the globe6, efforts to realize an integrated vision based on the notions and implications of 'smartness' and sustainability, including the standardization efforts needed to assess their efficiency, are still in the early stages. As the momentum of SSC continues to grow, there is an increasing need to better understand and foster the use of new technologies, particularly of rapidly diffusing Information and Communication Technologies (ICTs). Addressing this need is at the core of the Focus Group on Smart Sustainable Cities' (FG‐SSC) mandate. ____________________ 2 UNDESA (2014), 'World Urbanization Prospects: The 2014 Revision, Highlights', United Nations, Department of Economic and Social Affairs, Population Division. http://esa.un.org/unpd/wup/Highlights/WUP2014‐Highlights.pdf 3 UNDESA (2013),'World Economic and Social Survey 2013: Sustainable Development Challenges Overview', United Nations Department of Economic and Social Affairs (UNDESA), http://www.un.org/ en/development/desa/policy/wess/wess_ current/WESS%20Overview%202013%20E.pdf 4 UNFPA (2007) 'State of the World Population 2007: Unleashing the Potential of Urban Growth', United Nations Population Fund (UNFPA), http://www.unfpa.org/swp/2007/english/introduction.html 5 Provoost, R. (2013), 'Smart Cities: Innovation in Energy will Drive Sustainable Cities', The Guardian Professional, 13 November, http://www.theguardian.com/sustainable‐business/smart‐cities‐innovation‐energy‐sustainable 6 See for example the Partnership for Smart and Sustainable Cities, http://www.urbanknowledge.org/smartsustainablecities.html