Dobby的网络仿真学习笔记(ns2+qualnet)

Ad-Hoc Routing Protocols (Characteristics)

Classification of the Characteristics of Ad-Hoc Protocols and Routing-Strategies

Extension of Lang2003 and Murthy2004.

---

In general, routing can be divided into two strategies:
Adaptive Routing vs. Not-Adaptive Routing

• Adaptive: Changes of the network-topology are adapted by the routing-strategy
• Not-Adaptive: The routing is done using fixed tables

---

For Ad-Hoc-Netorks, only adaptiv strategies are usefull.
Reactive Routing/On-Demand Routing vs. Proactive Routing/Table-Driven Routing vs. Hybrid Routing

• Reactive/On-Demand
  • A route is only calculated, when it is needed
  • Does not try to keep routing-information everytime to all node
• Proactive/Table-Driven
  • Routes are calculated before one is needed
  • Tries to keep routing-information to all nodes everytime up-to-date
  • Update of the tables:
    • Event-driven: only if a change is recoginzed
    • Periodically
• Hybrid
  • Reactive and Proactive at the same time
  • E.g.: Intra-Zone: Proactiv, Inter-Zone: Reactiv

---

Distance-Vector Routing vs. Link-State Routing

• Distance-Vector
  • Calculates the distance to all nodes
  • Exchange of these information only with the neighbours
• Link-State
  • Mesuare the distance to the neighbours
  • Exchange of these information with all nodes

---

Flat Routing vs. Hierarchical Routing / Clustered Routing

• Hierarchical Routing / Clustered Routing:
  • Trying to structure/cluster the network
  • Clusterhead:
    • Responsible for the creation and extension of a cluster
    • Builds up a hierarchie of clusters
    • Manages the communication inside a cluster
  • Gateway-Node:
    • Responsible for the communication between clusters
    • Maybe bottleneck
• Flat Routing:
  • Network has no hierarchy

---

Geographical Routing / Positionbased Routing / Direction-Based Routing

• No routing-tables
• Information is send in any way in the direction of the destination
• No overhead to find or update routes

But:

• Position required
• Determination of the position via
  • internal search-process
  • external service

---

Uniform vs. Non-Uniform

• Uniform: All nodes are equal
• Non-Uniform: Some nodes have special roles, e.g. Clusterhead, Gateway-Node

---

Full vs. Reduced Topology Information

• Full: All topology-information will be distributed
• Reduced: Only a fraction of the known topology-information will be distributed

---

Past History vs. Prediction

• Past History: Information of past statuses is used to make a decision
• Prediction: Expectation of future statuses are used to make routing decisions

---

Broadcast

• Local Multicast: Only to some nodes in transmission-distance
• Local Broadcast: Only to the nodes in transmission-distance
• Networkwide Broadcast: Flooding
• Restricted Networkwide Broadcast: Flooding with a time-to-live

---

Recovery Strategy

• Mechansims to keep or to restore routes

---

Link-Reversal Routing

• Does not try to find an (somehow) optimal way
• Only tries to find any way

---

Source-Routing

• The sender specifies the way to go
• Under the circumstances, a node inbetween can decide to redefine the way

---

Route-Selection-Strategies

• Power-Aware Routing
• Signal Strength
• Link Stability
• Shortest Path
• Link-State Routing / Distance-Vector Routing
• Direction-Based Routing / Positionbased Routing / Geographical Routing
• Link-Reversal Routing
• Multipath Routing

"Ad-Hoc Protocols (Characteristics)" is mentioned on: Ad-Hoc Protocols

转自:

http://wiki.uni.lu/secan-lab/Ad-Hoc+Protocols+($28)Characteristics($29).html