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

为了实现宽带ISDN（B-ISDN），需要解决许多问题。其中，如何构建一个可靠的、高性价比的接入网，是目前接入网亟待解决的重要问题之一。本课题的研究目标是在我们提出的混洗环网络（SR网络）的基础上，设计一个这样的接入网或超高速网络，并进一步阐明和改善其性能，主要研究成果如下：1.给出了在实际情况下，即缓冲区容量有限的情况下，SR网络的业务处理性能。2.针对偏斜流量的对策提出，它表明，由于偏斜流量的交通性能的恶化，可以避免通过分布式的方式。3. SR网作为B-ISDN的接入网时，必须保证数据包的顺序。为了保持分组顺序，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，本文提出了双向洗牌环网络。提出了一些避免过载和路径分配的算法。5.提出了一种很好的多播方式，其中一定的带宽分配给每个呼叫和路由算法示出了更广泛的类网络，其中包括SR网络。6.本文从理论上给出了包括混洗环网在内的一般网络的呼叫级无阻塞条件。7.利用上述结果，给出了利用SR网络作为B-ISDN接入网和作为城域网的实际途径。

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.