Study on Very High - speed Multi - rane Network for B - ISDN

要实现宽带综合业务数字网(B-ISDN)，有许多问题需要解决。其中，如何组建一个可靠、高性价比的接入网是亟待解决的重要问题之一。我们的研究目标是在我们之前提出的洗牌环网(SR Network)的基础上，设计一种这样的接入网或甚高速网络，并澄清和进一步提高它的性能。主要研究结果如下：1.研究结果。给出了SR网络在实际情况下，即缓冲区大小有限的情况下的流量处理性能。2.提出了解决交通偏斜问题的对策，结果表明，采用分布式方式可以避免由于交通偏斜造成的交通性能恶化。当SR网络作为B-ISDN的接入网络时，必须保持分组的顺序。为了保持分组序列，示出了路径分配算法IQ，其中每个节点以完全分布式的方式确定到下一个节点的呼叫的路径。4.为了提高SR网络的可靠性，提出了采用双向环的双向洗牌环网络。文中还提出了一些避免过载和路径分配的算法。5.提出了一种为每个呼叫分配一定带宽的组播方法，并给出了包括SR网络在内的更大类网络的路由算法。6.从理论上给出了包括洗牌环网络在内的通用性很强的网络在呼叫层的无阻塞条件。7.利用上述研究结果，提出了利用SR网络作为B-ISDN的接入网和城域网络的实用方法。

Toward the realization of Broadband ISDN (B-ISDN) many issues are to be addressed. Among them, how to compose a reliable and cost-effective access network is one of the utmost important problem to be solved. The goal of our study is to design such an access network or very high speed Network based on the Shuffle Ring Network (SR Network) which we proposed before and to clarify and further improve the performances of it. The main results are as follows.1. The detailed traffic handling performance of SR Network under the practical condition, namely where the buffer sizes are finite are shown. 2. Countermeasures against the skewed traffic are proposed and it is shown that the deterioration of traffic performance due to skewed traffic can be avoided by an distributed manner. 3. It is mandatory to keep the sequence of packets when SR Network is used as an access network of B-ISDN. To keep the packet sequence, a path assignment algorithm iq shown in which each node determine the path for a call to the next node in a fully distributed fashion. 4. For the improvement of the reliability of SR Network, the Bidirectional Shuffle Ring Network is proposed in which a bidirectional rings are used. Some algorithms for overload avoidance and path assignment are also proposed. 5. An excellent way for multicast in which a certain band width is assigned to each call is proposed and an routing algorithm is shown for wider class networks in which the SR Network is included. 6. The non-blocking condition at call level is theoretically given for networks which are very generalize and which include Shuffle Ring Network. 7. Utilizing the above results, the practical way to utilize SR Network as access network for B-ISDN and as Metropolitan Area Network is shown.