Research On The Key Technologies Of High Performance Run Time Infrastructure Of Distributed Interactive Simulation

High Level Architecture (HLA) was approved for IEEE standard 1516 on September 2000. It introduces many advanced technologies into distributed simulation and makes the distributed interactive simulation technology develop rapidly. With the scale of distributed interactive simulation system getting larger and larger , the performance of current RunTime Infrastructure(RTI) cannot satisfy the increasing need of the applications, and the implementation technology of the high performance RTI has become a focus in distributed simulation domain. The key problem of it is to decrease the volume of information in network, and to enhance the efficiency of RTI, thereby solve the performance bottleneck of RTI. Nowadays, people are doing much more researches on the architecture and core algorithms such as Time Management, region matching, and object instance discovery of RTI.Based on the newest development of distributed interactive simulation technology and computer technology, the paper focuses on the research of key technologies of high performance RTI conformable to IEEE1516.Firstly, the definitions and components of HLA/RTI are introduced briefly, the implementation architectures and their existing problems of the current RTIs are analyzed; then aiming at the requirements of large-scale distributed interactive simulation based on WAN (Wide Area Network), the design of hierarchical RTI servers based on CORBA and interoperability protocol is put forward. The hierarchical RTI servers can get interoperability between various software and hardware platforms. Various RTIs in the system can communicate directly and efficiently. The deployment of the system is flexible. Because there is a central RTI responsible for the global operation, the global data consistency of the system can be ensured. Since all RTI servers in the system can execute in parallel, the efficiency of large-scale simulation which uses the RTI on WAN can be greatly enhanced.Time management service is one of the main features which distinguish HLA from previous distributed interactive simulation standards. Its implementation method can affect the efficiency and validity of simulation directly. The key problem of the implementation of time management service is the computation of Greatest Available Logical Time (GALT). Aiming at the possible deadlock problem of the current GALT algorithm, an optimized algorithm called recursive GALT (R-GALT) algorithm along with the idea of recursive advancing check is proposed. A formalized verification is also presented. Comparing with the original algorithm, the new algorithm can not only enhance the efficiency, but also avoid deadlock.To decrease the redundant data received by federate and the volume of information in network, data distribution management implements filtration based on value. To implement precise region matching with great efficiency is the goal of the implementation of data distribution management. After analyzing the advantages and disadvantages of several algorithms of region matching, a more effective matching algorithm called RMIB (Region Moving Information Based) algorithm is proposed. Its main features are as follows: representingthe upper bound and lower bound of a range with two nodes and storing all the nodes of the ranges of a dimension into an indexed ordered table, using the information before and after moving a region and limiting the matching computation only in the area of moving. Thereby it greatly decreases the candidate ranges that need to do matching computing, and therefore decreases the matching complexity, and obtains precise matching with high performance. This algorithm is extremely suitable for the large-scale distributed simulation that has a large number of regions.Object instance discovery is the precondition of data exchange via object instance. Related concepts of object instance discovery are analyzed and the key problems of object instance discovery are studied, then two efficient discovery algorithms named ROWUP Algorithm and SOWDOWN Algorithm are presented: one is used when reg...