Page 710 - Shaping smarter and more sustainable cities - Striving for sustainable development goals

express the information as application programmable interface (API) for application programmers
as a programming standard. As associated with these information, the information of management
status is indispensable, such as duplication or backup layer of the data, storage of the data
(datacenter or local server), latency and throughput to get the information, regulations in user,
group, throughput, date or time, amount of fetching, count of accessing, ID or address in network
and application layer, and accounting. Moreover, if API, security software/application, and other
middlewares such as database, machine learning is used, the name and version of this software are
required. This management can be the basement of privacy preserving. If the data management is
not well organized, the following problems and risks will appear.
 Falsifying data or illegal overwriting/deletion/wiping of data

If appropriate security is not given, falsifying attacks damage data by illegal overwriting, deletion,
and wiping.

 Slow or imperfect recovery from attacks

Data provider should provide the information on its data protection and security level before making
it available. In some cases, they will provide additional backups or options of security to meet their
requirements. If it is not considered, slow recovery or imperfect data recovery may occur more
serious than they expected.
 Privacy invading

Those who provide privacy data require a clear expression of the data, such as management status,
number or type of applications, and number or type of users or the providing data.
 Increasing the cost of data guarantee services and insurance services

Data guarantee services and insurance services providers require to know the status of data
management of smart sustainable city. If the status is not clear or missing, the cost of providing
services will be increased. From the application viewpoints, these problems and risks may bring
serious compromises by paralyzing infrastructures in smart sustainable city.

As described above, the infrastructure of SSC has to give a way to express the status of data
management, the format of data contents, management information, authorization, and certification.

On that basis, the way to distribute data and to keep consistency of distributed data is required as a part
of data infrastructure of SSC. According to the data distribution, hierarchical multi‐grain network
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architecture for smart community is proposed by IEEE Standards Association . Every service on a smart
sustainable city should select the layer of the hierarchical network where a service is provided and
processed. The consistency of the data is also managed by a distributed database in a hierarchical
network architecture. This means discussion of locality and latency is the key to data consistency in the
SSC. CAP theorem in theoretical computer science states consistency, availability, and partition
tolerance cannot be guaranteed simultaneously, and one of them has to be omitted in designing
systems. A model, which guarantees consistency and availability, supports hard real‐time services with
data consistency. In applications of SSC, the model is applicable to traffic signal control and power grid
management of power stabilization service in a local area. However, single point of failure lurks in a
system using the model because it does not guarantee partition‐tolerance. A model, which guarantees
availability and partition‐tolerance, supports wide‐area low‐latency services such as naming rule service,
sensor node management, and location services. In this model, consistency process becomes slower

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22 Hiroaki Nishi, Koichi Inoue, et al.; IEEE SMART GIRD VISION FOR VEHICULAR TECHNOLOGY: 2030 AND BEYOND; IEEE
Standards Association, pp. 41‐42, Jan., 2014.

700 ITU‐T's Technical Reports and Specifications