-
无线自组织(Ad hoc)网络中移动节点的主要特征是带宽低、移动性、能量有限。将适应于固定网络的传统路由协议应用到Ad hoc网络中,会存在路由表生命周期短、耗费大等问题,不适应于无线动态网络。在Ad hoc网络中,节点的移动性及节点能量有限,促使在Ad hoc网络中建立路由是一项既具挑战性又十分重要的工作。
文献[1-3]借助网络拓扑改善网络性能,在Ad hoc网络中把搜索路径简化到连通支配集进行路由[3-8]。支配集中的节点称为网关节点/主机(gateway host),这意味着仅仅网关节点需要保持路由信息[3]。只要网络拓扑改变没有影响到连通支配集,就不需要重新计算路由表。文献[3]提出一种简单、有效的分布式计算CDS的算法,但此方法得到的连通支配集并不是最优的。文献[4]针对支配集节点能量消耗均衡的问题,提出了轮流成为支配集节点的改善方法。文献[5]将连通支配集方法扩展到单向链路网络中。文献[6]说明了生成最小连通支配集的完全NP难事实,为了避免信息冗余的影响,对支配集进行扩展。文献[7-8]分别对于网络能耗和信息冗余方面进行改善,以提高Ad hoc网络的性能和改善能耗。文献[9]对于城市交通网络提出基于连通支配集的骨干网络,用以避免局部数据阻塞和数据延迟大问题。文献[10]基于区域的网络构建和维护稳健的连通支配集。上述这些算法大多局限于路由节点的产生和构建,对于网络本身拓扑信息却很少涉及,属于“拓扑未知”类方法,故而得到的支配集并不是最优的,所以网络性能也没有达到最优。最小连通支配集的完全NP难问题依然悬而未决。本文提出的改进算法是一种全分布式无中心“拓扑可知”方法,通过网内分布式计算合理利用拓扑相关信息,提升网络性能。
本文结合图谱理论中的特征矢量中心性对文献[3]所述的CDS方法进行改进,通过网内分布式计算获得网络拓扑的相关信息,对最小连通支配集的完全NP难问题进行了妥善解决,结合网络拓扑信息得到最优连通支配集,并给出相关定理及证明。同时,对网络拓扑改变时的更新/重算方法进行了改进。
An Improved Formation Method of Connected-Dominating Set in Ad Hoc Wireless Networks
doi: 10.3969/j.issn.1001-0548.2017.06.004
- Received Date: 2016-05-17
- Rev Recd Date: 2017-04-11
- Publish Date: 2017-11-30
-
Key words:
- Ad hoc wireless networks /
- dominating sets /
- routing /
- topology /
- undirected graph
Abstract: The formation method of connected-dominating set (CDS) in ad hoc wireless network is studied and improved. There are two improvements in this paper, the first one is numbering the nodes by introducing the eigenvector center value of the network topology information, which avoids the randomness during node reduction and makes the node reduction be related to the actual network topology closely. The second one is that CDS algorithm ignores the removal of the largest numbered nodes, the improved one proposes a new rule to achieve the reduction of the maximum number nodes. Thus, the improved method solves the NP-complete problem of the CDS algorithm in formation method of connected-dominating set and achieves the conditional optimal connected-dominating set. The simulation results show the excellent characteristics of the improved method.
Citation: | HUANG Qing-dong, YAN Qiao-qiao, SUN Qing. An Improved Formation Method of Connected-Dominating Set in Ad Hoc Wireless Networks[J]. Journal of University of Electronic Science and Technology of China, 2017, 46(6): 819-824. doi: 10.3969/j.issn.1001-0548.2017.06.004 |