Page 86 - Big data - Concept and application for telecommunications

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Appendix I

General procedure for data exchange
(This appendix does not form an integral part of this Recommendation.)

This appendix provides a general procedure of data exchange.

A data exchange context is the framework in which two or more systems agree to exchange identified sets
of data and related attributes.

Concerning the interoperability of data exchange between systems, the following two fundamental issues
have to be considered:
– the semantics of the content and the logical structures of data (application schema);
– a system and platform-independent data structure that can represent data corresponding to the
application schema (for example a vendor neutral or well-known data format.
NOTE 1 – An application schema is a conceptual schema for applications which defines content and structure
of the data (e.g., eXtensible Markup Language (XML) based metadata interchange).
NOTE 2 – Data exchange between homogeneous systems (which are using the same format and/or schema)
means fewer interoperability issues to be solved than data exchange between heterogeneous systems (in
which the used format and schema are different).

Figure I.1 provides a procedure of data exchange between two systems.

Figure I.1 – Data exchange procedure

Between System A (which has source schema sa, data format Fa) and System B (which has target schema sb,
data format Fb), the data exchange takes place with the following two steps:
– encoding data: this includes mapping the Sa source schema onto application schema
i (cf. "mapping_ai" in the figure), and converting the data format Fa to n (cf. "converting_an" in the
figure);

– decoding data: this includes converting the data format n to Sb (cf. "converting_nb" in the figure),
and mapping application schema i with target schema B (cf. "mapping_ib" in the figure).

In general, the following preconditions have to be considered concerning data exchange:
– the application domains of each system are same or similar;
– the application schemas of each system are similar enough for allowing conversion from one to the
other.

78 Moving data – Data exchange and data flow