Federate-Level Reusability: Joining a Federation with SOM Document Data
Jae‐Hyun Kim · 2004
The current HLA specifies that all federates need to have the same copies of FOM Document Data(FDD) designated while creating a federation. This scheme simplifies the initialization phase of the federate since FDD has all required data. This restriction, however, has some problems. An information hiding problem is occurred when two or many federations from different organizations form a unified federation. The organizations need to expose all data within their federation even if they do not want to expose. Another problem happens when the FOM is modified. All federates in a federation ought to modify their FDD files although the modification is not directly related to their object model. Finally, a federate should maintain a set of FDD files of every federation with which it joins. This paper proposes a new scheme that eradicates these problems; a federate joins a federation with its SOM Document Data (SDD) file instead of FDD. Like a FDD file, SDD contains SOM data required at run-time. A federate and its SDD become a unit of reuse, since SDD is in fact an interface to the federate. This set, i.e., the federate program and its interface description, is able to join any federation without modification. Since it is unnecessary to know other data that is not related to the federate, the information hiding problem and other FOM maintenance problems will be disappeared. In order to support this scheme, the paper proposes modification to Join Federation Execution service and associated algorithms that process the join service with SDD.