Mobile Ad-hoc Networks (MANETS) consists of a collection of mobile nodes without having a central coordination. In MANET, node mobility and dynamic topology play an important role in the performance. MANET provide a solution for network connection at anywhere and at any time. The major features of MANET are quick set up, self organization and self maintenance. Routing is a major challenge in MANET due to it's dynamic topology and high mobility. Several routing algorithms have been developed for routing. This paper studies the AODV protocol and how AODV is performed under multiple connections in the network. Several issues have been identified. The bandwidth is recognized as the prominent factor reducing the performance of the network. This paper gives an improvement of normal AODV for simultaneous multiple connections under the consideration of bandwidth of node.
Quality of Service Provisioning in Manet Using a Cross-Layer Approach for Routing
在移动自组网中部署多媒体应用需要保证服务质量(QoS)。然而,有限的电池功率,其他资源的限制和移动性的节点使得QoS提供难以在移动自组网中实现。这个困难可以通过使用跨层路由方法来克服。在[1] Patil等人中,提出了一种跨层路由协议CPACL-AODV(Cost Based Power Aware Cross Layer),克服了节点电池电量的限制。虽然许多类似的能源效率和跨层路由协议已经提出了移动自组网,他们没有处理QoS。提出了一种新的MANET路由协议TSPBA-AODV(Type of Service,Power and Bandwidth Aware AODV),该协议克服了资源约束,同时采用跨层方法提供QoS保证。此外,在两种不同类型的网络业务中,比较了节点移动性变化对TSPBA-AODV和CPACL-AODV [1]性能的影响。如所示的模拟结果进行,TSPBA-AODV表现优于CPACL-AODV的MANET中,节点移动速度小(速度高达40公里/小时左右)。此外,还研究了节点数据发送速率的变化对协议性能的影响。仿真结果表明,TSPBA-AODV在所有节点数据发送速率的变化下都优于CPACL-AODV。
Treatment of Reactive Routing Protocols Using Second Chance Based On Malicious Behavior of Nodes in MANETS
在移动自组网中,不同路由协议的移动节点在数据的发送和接收上遵循不同的策略。安全性、数据包投递和路由开销是任何协议设计过程中的重要考虑因素。网络中恶意节点的存在与否对协议的性能影响很大。本文主要针对移动自组网中的反应式路由协议,研究网络中节点的威胁、攻击以及恶意行为产生的原因。DSR和AODV是两个反应式路由协议,被认为是为研究提出了第二次机会的策略,考虑到恶意行为的原因,以提高数据包的交付率和减少路由开销的网络中的节点。利用Ad hoc Simulator(ASIM)对DSR和AODV路由协议在有恶意节点和无恶意节点情况下的性能进行了仿真研究,结果表明,在无恶意节点情况下,DSR和AODV路由协议的分组投递率较低,路由开销较大。第二次机会策略考虑了恶意行为产生的原因,帮助节点重新融入网络,提高了数据包的投递率,降低了路由开销。
DiffPerf: Towards Performance Differentiation and Optimization with SDN Implementation
School of Computing, National University of Singapore(新加坡国立大学计算机学院);Trustwave, Singapore(Trustwave);Bigo Technology Pte Ltd, Singapore(Bigo Technology Pte Ltd)