The system logic structure has innumerous effect to the development, execution, and scalability of multi-federation system. A multi-federation system based on tree-topology structure was provided. Federations in the system were connected through proxies. Each federation was connected only with federations directly upper and lower. Thus multi-channels and loops in data transmission were avoided. A strategy was also presented to synchronize time advancement in real time multi-federation systems using RTI (run-time infrastructure) time management. Time-regulation federates and time-constraint federates in multi-federation systems were settled specially to ensure that synchronization signals created in root federation could be transmitted to leaf federations through tree-topology. The synchronization of time advancement of the whole system was realized. The time delay of synchronization signals in system was also analyzed as a result a time-delay formula was given. This formula reveals that more levels in system structure would lead to more delay.
����.���ӷֲ�����ϵͳ���̿�����RTI���������о� .����:�������պ����ѧ�Զ�����ѧ���������ѧԺ,2001 Lin Xin. Research on engineering development of complex distributed simulation system and RTI interoperability . Beijing:School of Automation Science and Electrical Engineering, Beijing University of Aeronautics and Astronautics, 2001(in Chinese)
�Ź���,����,������.������ϵͳ����ԭ���ʱ���ӳٵ�̽���о�[J].ϵͳ����ѧ��,2002,14(3):300-302 Zhang Guofeng, Lin Xin, Wang Xingren. Study on construction principle and time delay of multi-federations[J].Journal of System Simulation, 2002,14(3):300-302(in Chinese)
����,��С��.��ɢ��ѧ����Ӧ��[M].����:���ӹ�ҵ������,1997:141-176 Fu Yan, Gu Xiaofeng. Discrete mathematics and its applications[M]. Beijing:Publishing House of Electronics Industry, 1997:141-176(in Chinese)
 IEEE Std 1516.1-2000, IEEE standard for modeling and simulation (M&S) high level architecture (HLA) federate interface specification [S]
 IEEE Std 1516.2-2000, IEEE standard for modeling and simulation (M&S) high level architecture (HLA) object model template (OMT) specification [S]
 IEEE Std 1516-2000, IEEE standard for modeling and simulation (M&S) high level architecture (HLA) — framework and rules [S]