摘要
容延网络具有网络拓扑频繁割裂、节点密度稀疏和移动性等特点,由于很难捕获全局拓扑知识,因而其路由设计面临着巨大挑战.当前多数基于节点局部信息的路由算法在下一跳中继节点选择时,都直接依赖于节点的位置信息,然而容延网络中节点的位置在时刻变化,这在一定程度上影响了路由选择的准确性.在多数容延网络中,节点往往是在移动一段距离之后才会改变方向,因而方向信息比位置信息更加稳定和可靠.基于此,提出一种基于移动方向的路由算法MDCE,同时借助有效的缓存管理进一步提高了路由性能.大量仿真实验表明在基于Random Waypoint节点移动模型的网络环境中,与Epidemic和Prophet相比,MDCE在消息投递率、网络负载率、平均跳数、丢包数上均取得了一定优势,MDCE平均跳数和丢包数更少,负载率不及Epidemic的40%,不及Prophet的75%.
Delay Tolerant Networks （ DTNs ） feature frequent network topology partition, sparse node density and node mobility etc, which determines that it is difficult to capture the global network topology, and consequently it is a great challenge in designing a rou- ting protocol for DTNs. When selecting the next-hop relay nodes, most routing algorithms based on nodes＇ local information are de- pendent on the nodes＇ geographical information. However, since the position for each node in DTN changes at every moment, it will impair the accuracy of routing selection to some extent. From another perspective, nodes generally move some distance along a direc- tion before changing another direction in most current DTNs environment, which implies the direction information is more stable and reliable than the position information. Based on this observation, this paper proposes a Moving Direction based Controlled Epidemic routing algorithm, MDCE, and resorts to an efficient buffer management policy to further enhance the routing performance. Extensive simulations have been conducted and the results demonstrate that MDCE outperforms Epidemic and Prophet in terms of message deliv- ery ratio, network overhead ratio, average hop count and dropped message number in a Random Waypoint mobility model based DTN environment. Specifically, MDCE has less average hop count and dropped message count than Epidemic and Prophet and the over- head ratio of MDCE is less than 40% and 75% of Epidemic and Prophet respectively.
出处
《小型微型计算机系统》
CSCD
北大核心
2015年第1期60-66,共7页
Journal of Chinese Computer Systems
基金
青岛市应用基础研究项目(12-1-4-2-(14)-jch)资助
山东省自然科学基金项目(ZR2013FQ022)资助
关键词
容延网络
路由算法
局部信息
移动方向
缓存管理
delay tolerant networks
routing algorithm
local information
moving direction
buffer management
