双环网络平均直径表示网络中信息传输的平均延迟,是双环网络优化设计的重要因素,与直径相比,平均直径很少得到研究,因此集中研究平均直径。定义一族双环网络N-family,提出一种计算双环网络平均直径的方法,发现一些紧优双环网络尽管直径最小,而平均直径并没有达到最小。定义一类双优双环网络,它不仅直径达到下界,而且平均直径在N-family小。
The average diameter,which represents the average information transmission delay of a double-loop network,is an import factor in designing an optimal-double loop network.However,up to now the average diameter received much less surveys than the diameter has.Hence,this survey focuses on the average diameter.A family of double-loop networks N-family is defined.A method to calculate the average diameter is proposed.It is found out that some tight-optimal double-loop networks having minimum diameter do not have the minimum average diameter.A type of double-loop networks,which has lower-bounded diameter and the minimum average diameter in its N-family,is defined as dual-optimal double-loop networks.