Page 366 - Shaping smarter and more sustainable cities - Striving for sustainable development goals

6.2 SSC ICT Meta‐Architecture

All the aforementioned specifications and requirements analyze the SSC in the following
components, which must be integrated via the proposed SSC ICT architecture:

 Soft infrastructure: people, knowledge, communities
 Hard infrastructure: buildings, networks (transportation, telecommunications), utilities (water,
energy, waste)

 ICT‐based innovative solutions: both hardware and software solutions, which address the above
hard and soft infrastructure
 Other innovative solutions (beyond the ICT): technological innovation that addresses smart city
dimensions (i.e., open spaces, recycling system, smart materials, organizational innovations in
government, etc.)

 Natural environment: concerns the physical landscape and the corresponding characteristics,
where the city is installed (i.e., ground, forests, rivers, lakes, mountains, flora, etc.) and grounds
the limitations for the hard ICT infrastructure installation.

An indicative n‐tier architecture where physical, utility and ICT environments co‐exist and interact,
while people and businesses are also part of the SSC eco‐system and interact with the smart city via
SSC services is illustrated on (Figure A.1). In [7] various smart sustainable cities around the world
were explored and an important outcome concerns that the architecture that is preferred by well‐
managed managed cases is the multi‐tier (Table 1), which is applied in new, existing and smart
planting cases, while it addresses both soft and hard infrastructure, while it considers natural
environment and the evolving Internet‐of‐Things (IoT) in terms of sensor installation. Another
architectural approach concerns the Service Oriented Architecture (SOA) (Figure A.2), which is
proposed for existing cities, where innovation mainly focuses on soft infrastructure, as well as where
IoT is utilized (Figure A.3). Finally, event‐driven architecture (EDA) is proposed (Figure A.4), but it
has not been applied yet. Table 1 shows that architecture is independent to the ICT solutions that is
applied in the city, as well as independent to the smart city organization (Public organization, State‐
Owned‐Enterprise (SOE), Project coalition or Private Company).

All the given information collected from literature and case studies suggest that the meta‐
architecture of the SSC must be multi‐tier in order to be clear and sustainable, in terms of
standardization and communication of these standards. According to the examined cases, this n‐
tier architecture must utilize hard and soft infrastructure and must contain the minimum following
layers (Figure 5) from top to bottom:

Layer 1) Natural Environment: it concerns all the environmental features where the city is located
(landscape, rivers, lakes, sea, forests, etc.).

Layer 2) Hard Infrastructure (Non ICT‐based): it contains all the urban features, which have been
installed by human activities and are necessary for city operation (buildings, roads, bridges, energy‐
water‐waste utilities, etc.).

Layer 3) Hard Infrastructure (ICT‐based): it concerns all smart hardware, with which SSC services
are offered (i.e., datacenters, supercomputers and servers, networks, IoT, sensors, etc.)

356 ITU‐T's Technical Reports and Specifications