Research on Optimizeation of Implementing Telephone Netwarks by Using Learning Theory

1992年，通过将我们之前提出的学习控制方案应用于电话网络，我们设计并提出了一种以网络负载均衡为目标的路由方案。该方案从一组适当确定的路由中选择一条加权阻塞频率最小的路由。结果表明，该方案在阻塞频率在路由集上渐近相等的意义上实现了负载均衡。计算机仿真结果表明，该方案在阻塞数和平均路由长度方面优于使用学习自动机的方案。然而，发现负载均衡的特性在很大程度上取决于路由集的确定。鉴于近年来网络观测和控制功能的快速发展，我们可以期待比1992年所考虑的更高性能的路由是可以实现的。在此基础上，我们于1993年提出了一种基于各站呼叫产生信息的学习路由方案，实现了更严格的负载均衡。该方案通过自适应地将产生拥塞的主源的溢出呼叫分配给空路由来寻求链路间的阻塞均衡。详细的计算机仿真结果表明，在利用前人提出的路由域设计方法确定路由集的情况下，在各种条件下，新方案都优于原有方案和状态依赖方案。本研究的意义在于从理论上和实践上证明了我们的方案能够实现现有方案无法保证的负载均衡。我们的研究结果对未来可行的路由方案的开发有一定的参考价值。

In 1992, by applying our previously presented learning control scheme to a telephone network we designed and presented a a routing scheme with aim at load equalization on the network. This scheme chooses a route which minimizeds a weighted blocking frequency from an appropriately determined set of routes. It was shown that this scheme achieves the load equalization in the sense that the blocking frequencies asymptotically become equal amoug the set of routes. According to computer simulation, it was ascertained that our scheme is superior in blocking count and average route length to the scheme using learning automata. However, it was found that the characteristic of load equalization greatly depends on determination of the set of routes.Viewing recent rapid development of functions of network observation and control, we can expect that higher performance routing than that considered in 1992 is realizable. From this, in 1993, we presented a learning routing scheme which achieves more strict load equalization based on information about call generation at all stations. This scheme seeks blocking equalization among links by adaptively assigning overflow calls from main sources generating congestion to vacant routes. According to detailed computer simulation, it was ascertained that our new scheme is most superior compared with our previous one and the state-dependent scheme under various conditions in the case that we determined the set of routes using the design method of a routing domain presented by other investigators.Significance of this research is that it was shown theoretically and practically that our schemes achieve load equalization which is not ensured by the present schemes. Our research results will be useful for development of available routing schemes in future.