通信网络设计:传输容量、设计代价和可扩展性

虽然目前围绕复杂网络的流量动力学研究日益增多,但这类研究尚存在一些共性问题.例如:所采用的网络流模型过于简单;没有考虑网络设计的代价和可扩展性.本文建立在一个更为真实的网络流模型之上,同时为网络设计问题提供了更全面的视角.本文在广为研究的传输容量之外又引入了另外两个设计目标:网络设计代价和可扩展性.通过引入笛卡尔坐标系统,本文量化分析了不同的网络设计因素是如何独立地影响以及通过相互作用共同影响这些网络设计目标的.结果表明,不同的网络拓扑结构呈现出不同的网络设计可行解空间形状,并在实现高效费比和可扩展的网络设计目标上表现出不同的能力.特别地,文章指出现有的经验性网络设计背后隐藏的理念不能满足高效费比和可扩展的网络设计需求,并提出了针对BA网络的一种高效费比和可扩展的设计方案,即有效路由结合基于有效介数的链路带宽分配方案.而如果从头开始设计一个全新的网络,则随机网络是达成上述目标的最佳选择.

Communication network designing:transmission capacity,cost and scalability

Despite the growing number of works centering around the traffic dynamics on complex networks,these researches still have some common shortcomings,e.g.,too simple traffic flow model and lack of considerations for the designing cost and scalability issues.This paper builds on a more realistic traffic flow model,and offers a holistic view on the network designing problem.In addition to the extensively studied transmission capacity,this paper takes designing cost and scalability as two other designing objectives,and presents a quantitative study of how different designing choices independently and collectively influence these objectives by the introduction of a cartesian coordinate system.It is shown that different kinds of network topologies display different shapes of achievable solution spaces and exhibit different abilities to achieve cost-effective and scalable designing.In particular,we find the philosophy underlying empirical network designing and engineering today fails to meet the cost-effective and scalable designing requirements,and propose a cost-effective and scalable designing scheme for BA-like networks,i.e.,the efficient routing combined with effective betweenness based link bandwidth allocation.In addition,when designing a thoroughly new network from the beginning,we find that ER network is a good candidate to achieve cost-effective and scalable designing in most settings.