scope:

The emphasis in modem system building has shifted from interconnecting a mixture of stand alone systems towards networking intelligent components to form a flexible system. New combat systems follow the same evolution. This results, amongst others, in the introduction of multi-function consoles, which allow for different tasks and roles to be attributed to the same operator console, and the implementation of shipboard Local Area Networks (LANs) replacing dedicated point to point connections.

As combat systems become more flexible, and functions previously contained within a single equipment become distributed across the system, there is a growing need for the co-ordination and consistency in the definition of all information passed between elements of the combat system.

Communication between the different components of a naval combat system is based on messages. A message contains data in a pre-defined structure which not only includes the order of the data elements, but also the type and size. A message definition thus contains the meaning of each of the elements of a message.

In the context of this document, a project is regarded as the complete process of procuring a Naval Combat System, either by a National authority, or in a multi-national context. A Project Information Catalogue is the definition of the structure of all the different messages equipment can send over the shipboard LAN. This implies that all message structures are pre-defined, and no new ones are to be created during operation.

One of the elements generated by the NIAG/SG-52 study on a Shipboard Open Systems Environment is the NATO Naval Combat System Information Catalogue. The Information Catalogue was enhanced by NIAG/SG-52 as part of a subsequent study on Naval Combat System (NCS) Architecture Design Principles Standardization. The Information Catalogue is aimed at defining a Generic Information Catalogue that can be adopted by projects as the starting point to create a Project Information Catalogue and includes:

a. A Generic Message Catalogue [Ref 2], defining the content and structure of messages which are transmitted between functions, applications or equipment in a Combat System. Transmitted messages comprise a message header (containing information relating to the whole message) and a message body (containing an ordered list of message elements).

b. a Data Structure Catalogue [Ref 3], defining the detailed and unambiguous structure of each message element defined in the Generic Message Catalogue

It has been recognized that, for a number of reasons, projects will need to extend the Information Catalogue with additional project-specific messages or with additional information extending a generic message. This has been supported by the development of a NATO Naval Combat System Message Construction Standard [Ref 4] which defines the syntax and rules for the definition of messages and data structures and for creation and extension of messages.

In essence, this extends the concepts contained in STANAG 4222 [Ref 61 to include standards for the construction of data structures and messages.