scope:

Foreword

The high level architecture (HLA) has been developed to provide a common architecture for distributed modeling and simulation. To facilitate interfederate communications, HLA federates interact with an underlying software infrastructure. This specification defines the standard services and interfaces to be used by the federates to support efficient information exchange when participating in a distributed federation execution. (A federation execution occurs when sets of federates are brought together to support an objective.)

This document is being developed to define the HLA interface specification. The HLA requires a language independent specification (LIS) and multiple language bindings to support intersimulation communication in a distributed simulation domain.

The formal definition of the modeling and simulation (M&S) high level architecture comprises three main components: the HLA rules, the HLA federate interface specification, and the HLA object model template (OMT). This document shall provide a complete description of the essential elements of the second component of the HLA, the interface specification. The other two components of the HLA formal definition are described in the documents listed in Clause 2.

The high level architecture is an integrated architecture that has been developed to provide a common architecture for M&S. The HLA requires that interfederate communications use a standard application programmeris interface (API). This specification defines the standard services and interfaces to be used by the federates in order to support efficient information exchange when participating in a distributed federation execution. Additionally, the capability for reuse of individual federates that adhere to these standard services and interfaces is increased.

This document provides a specification for the HLA functional interfaces between federates and the runtime infrastructure (RTI). The RTI provides services to federates in a way that is analogous to how a distributed operating system provides services to applications. These interfaces are arranged into seven basic service groups as follows:

a) Federation management

b) Declaration management

c) Object management

d) Ownership management

e) Time management

f) Data distribution management

g) Support services

The seven service groups describe the interface between the federates and the RTI, and the software services provided by the RTI for use by HLA federates. The RTI requires a set of services from the federate that are referred to as ìRTI initiatedî and are denoted with a Ü (printerís dagger).

Any software acting as an HLA RTI shall implement all of the federate initiated services in accordance with this specification. Likewise, any software acting as an HLA federate shall implement all of the RTI initiated federate services in accordance with this specification.

Scope 

This document defines the interface between federates (simulations, supporting utilities, or interfaces to live systems) and the underlying software services that support interfederate communication in a distributed simulation domain.