Appendix 2 - Description for the Harmonized Specification of Technical Services in the Context of E-Navigation

 1 Maritime Services are implemented by a set of Technical Services. For harmonization, the Maritime Services are described by using a common template, as set out in appendix 1. This template includes references to technical services.

 2 The specifications are divided into three parts:

• .1 a service specification;

• .2 a service design description; and

• .3 a service instance description.

 3 The technical service specification covers the technical/digital service on a general level to implement the Maritime Services. The service specification is still technology-agnostic. The service specification should include the following information:

• .1 MRN ID for the service specification;

• .2 reference to the Maritime Services which make usage of the Technical Services;

• .3 the operational context of the service in (e.g. requirements, use cases);

• .4 the service interface descriptions (operations, parameters);

• .5 the information provided and used by the service (the service data model);

• .6 the dynamic behaviour of the service (sequence of operations, behaviour description); and

• .7 author of the service specification (organization, contact person).

 4 A technical service specification will have one or several associated (technical) service design descriptions. Each technical design describes how the service is implemented using specific technologies. Service design descriptions should include the following information:

• .1 MRN ID for the service design description;

• .2 reference to the service specification;

• .3 description of the chosen technologies (data processing, communication technologies, infrastructure, networks, etc.);

• .4 detailed description of the used data structures and types (service physical data model, encoding);

• .5 mapping of the used data structures to the service specification's service data model; and

• .6 author of the technical design (organization, contact person).

 5 A technical service design will have one or several associated technical service instance descriptions. Each instance description is a reference (endpoint) to a specific service provider for this specific service following the specific design description. The instance description also contains additional information such as coverage area for the service providers' instance of the service. A service instance includes the following information:

• .1 MRN ID for the service instance description;

• .2 reference to the service technical design (and thus, implicitly, to the service specification);

• .3 information about service provider;

• .4 access/information (e.g. URL, frequencies etc.); and

• .5 geographical coverage information.

 6 The relationship between the different levels of service descriptions are shown in this example for a VTS service:

 7 In order to achieve a harmonized use of technical services, it is recommended to use guidelines developed by the domain coordinating bodies,^footnote if available.