zoukankan      html  css  js  c++  java
  • Routing & Network Knowledge

    This is a technical notes as I read the paper Routing in Delay Tolerant Networks.I should have written these words long before. I hope it is not too late.

    In that paper, K. Fall et al. create a set of abstract knowledge oracles, each able to answer questions we ask of them. These oracles are: 

    • Contact Summary Oracle. This oracle can answer question about aggregate statistics of the contacts. In particular, the contacts summary oracle provides the average waiting time until the next contact for an edge. Thus, the contact summary oracle can only respond with time-invariant or summary characteristics about contacts.
    • Contact Oracle. This oracle can answer any question regarding contacts between two nodes at any point in time. This is equivalent to knowing the time-varying DTN multi-graph. The contacts summary oracle can be constructed using the contacts oracle, but not vice versa.
    • Queuing Oracle. This oracle gives information about instantaneous buffer occupancies(queuing) at any node at any time and can be used to route around congested nodes.(Most difficult oracle to realize in a distributed system)
    • Traffic Demand Oracle. This oracle can answer any question regarding the present or future traffic demand. It is able to provide the set of messages injected into the system at any time.

       Routing algorithms fall into 3 classes:

    • Zero Knowledge.(First Contact)
    • Partial Knowledge.(no traffic demand oracle)
    • Complete Knowledge. 
    Computing Shortest(minimum cost) PathDelay Component:1,queuing delay;2,transmission delay;3,propagation delay.Given that edge capacities and propagation delays vary with time, we also expect route selection to vary with time. If edge cost is time-invariant, we can use Dijkstra's shortest path algorithm. 

  • 相关阅读:
    003. 爬楼梯
    ZFlie网盘框架说明
    WPF基础:Dispatcher介绍
    WPF自定义控件三:消息提示框
    GO Time 类型方法处理集合
    UserControl 加载动画
    WPF自定义控件二:Border控件与TextBlock控件轮播动画
    WPF自定义控件一:StackPanel 控件轮播
    WPF 图表控件之曲线绘制与移动
    VueApp 自动更新解决plus is not defined问题
  • 原文地址:https://www.cnblogs.com/jcleung/p/2052316.html
Copyright © 2011-2022 走看看