Page 363 - Shaping smarter and more sustainable cities - Striving for sustainable development goals

as the capability to install various hard infrastructure (simple for new cities and blocks, compared
to historical cities);

 Different timeframes within which the SSC ICT architecture is requested to operate (small
communities change more slowly and their needs accordingly, compared to global cities).

The architectural principles that enable the SSC ICT architecture to align to the above characteristics
concern:
– Layered structure: layered architecture has been proved to be applied in the mostly well
managed SSC cases and can be applicable to most cases. Some layers have already
introduced by the (ITU FG‐SSC 0097 specifications document on SSC infrastructure) such as,
the data and communication layer. However, exceptions have to be considered in cases
where the SSC is not centrally and simultaneously developed, such as many European cases.

– Interoperability: interoperability needs to be ensured among heterogeneous and
distributed systems in SSC for provision and consumption of a variety of information and
services.
– Scalability: SSC ICT architecture has to be able to scale‐up and down according to the size

of city, the demand for services or business changes within the SSC.
– Flexibility: cutting‐edge (i.e., cloud computing, IoT, etc.) and emerging technologies have be
able to be adopted, while physical or virtual resources have to be rapidly and elastically
adjusted to provide various types of SSC services.

– Fault tolerant: many quality attributes concern themselves with the availability of the
architecture and its hosted componentry. Although fault tolerance is a rather strong phrase,
it states the apex to which services and the architecture should aspire.
– Availability, manageability and resilience: service availability must be ensured according the
SSC user demand; disaster recovery must be provided in various levels; manageability
relates to operational concerns, in a sense that managing the architecture directly supports
SSC ICT operations. Manageability ‐at a systems/subsystems level‐ has to be secured in
order to allow normal operations of equipment, networks and applications, especially
considering more and more operation process would be managed automatically.

– Standards‐based: this principle has an identifiable tension with that of technology and
vendor independence. Essentially, an organization endorses this principle to ensure
contestability, replace ability, and longevity.

– Technology and/or vendor independence: SSC and mainly those that run under the State
supervision and/or funding, require that architectures, solutions, or services be vendor‐
independent, to facilitate contestability, replacement, or simpler interoperability or
integration. Of course, vendor independence may also compromise one's ability to
negotiate preferential rates or treatment, and it is not unusual for (larger) organizations to
nominate a preferred list of suppliers for certain services, allowing a degree of negotiation
to occur to support cost containment.

ITU‐T's Technical Reports and Specifications 353