研究了节点队列资源有限的条件下,无标度网络上的信息流动力学过程,发现了网络由自由流通到拥塞的相变现象,提出了一种基于节点度的队列资源分配模型.模型的核心是使节点i的队列长度与kβi成正比(ki为节点i的度,β为分配参数).仿真结果表明,在网络使用最短路径算法进行信息包传送的条件下,β近似等于1.25时队列资源分配最合理,网络容量最大,且该最佳值与队列总资源多少以及网络的规模无关.
In this article,information traffic dynamics in scale-free networks with limited queue resource is investigated firstly. It is found that the network transits from a free flow state to full congestion state with the increase in the packet generation rate. Then,a queue resource allocation model based on node degree is proposed. The core of this model is to make the queue length of node i proportional to kiβ (ki being the degree of node i and β being an allocation parameter). Simulations show that the capacity of the scale-free network is maximal when β is about 1. 25 for the shortest path algorithm used to transfer information. Furthermore,the optimal value of allocation parameter β is irrelevant to the network size and the amount of queue resource.