基于社区层次的机会网络移动模型

摘要

由于目的节点和源节点之间不存在一条完整的通信链路，因此机会网络是通过利用节点的移动带来的相遇机会以“存储-携带-转发”的形式实现节点之间通信的一种移动网络。虽然机会网络的通信延迟较大，但是在一些无法建立完整的通信链路的环境中（如手持设备组网和车载网络中）机会网络能更好地满足一些基本需求。而在机会网络研究中搭建现实场景基本上是不可能的或者代价过高，因此主要是通过做仿真实验来再现现实环境，而模拟节点运动的移动模型是仿真研究的重要基础。特别是在手持设备机会网络中，移动模型对现实的模拟程度，将在很大程度上影响下一步的研究，因此不少学者基于社会复杂网络提出了一些不错的移动模型。文章在最近研究的基础上了提出了社区层次的概念，提出了一种基于社区层次的移动模型，从社区的层次角度分析了节点的相同和区别，实现了不同层次节点在选择移动方式和目标时的差异性。通过实验得出位于ACTIVE层节点的累计相遇节点数要高于位于STEADY层中的节点，这一结果表明ACTIVE层节点具有一定的外交能力，频繁活跃于不同社区，符合现实中某些节点的特征，从模拟现实的角度分析，CTMM移动模型适合手持设备组成的机会网络。%Because there is not a complete communication route between source node and destination node, so opportunistic network is supposed to solve it in the form of store-carry-transmit, which make use of the chance bring by the mobile nodes. Although opportunistic network has high communication delay, it has been used in some environment which can’t build a complete network route, for example network of handheld device, vehicular delay tolerant network. But in opportunistic network research, it is hard or impossible to build a real scene, so that researcher use simulation experiment to represent the real world. And the mobility model which to simulate the way of move pattern is the foundation of simulation. Particular, in opportunistic network of handheld device, the realistic extent of mobility model can heavily affect the further research, so someone propose some effective mobility model base on social complex networks theory. In this paper, based on recent literature, we propose a community tier based mobility model (CTMM), which analyse the same and the difference between the nodes form angel of community tier, and realize the otherness of node in item of choosing the mobile way and goal. The results indicate that the node in ACTIVE have a higher meet cumulative number of nodes than the node in STEADY, which result from node in AVEIVE always move between different community. In term of accurately of real world, CTMM can be used in opportunistic network of handheld device.