31-05-2012, 03:14 PM
Routing Protocolsin MANETs
RoutingProtocols.ppt (Size: 300 KB / Downloads: 204)
What is a MANET
Mobile nodes, wireless links
Infrastructure-less: by the nodes, …
Multi-hop routing: …, and for the nodes
Minimal administration: no hassles
What’s unique about a MANET ?
Moving nodes ever changing topology
Wireless links
various and volatile link quality
Pervasive (cheap) devices
Power constraints
Security
Confidentiality, other attacks
Challenges in MANET Routing
Need dynamic routing
Frequent topological changes possible.
Very different from dynamic routing in the Internet.
Potential of network partitions.
Routing overhead must be kept minimal
Wireless low bandwidth
Mobile low power
Minimize # of routing control messages
Minimize routing state at each node
MANET Protocol Zoo
Topology based routing
Proactive approach, e.g., DSDV.
Reactive approach, e.g., DSR, AODV, TORA.
Hybrid approach, e.g., Cluster, ZRP.
Position based routing
Location Services:
DREAM, Quorum-based, GLS, Home zone etc.
Forwarding Strategy:
Greedy, GPSR, RDF, Hierarchical, etc.
Reactive Routing
Key Goal: Reduction in routing overhead
Useful when number of traffic sessions is much lower than the number of nodes.
No routing structure created a priori. Let the structure emerge in response to a need
Two key methods for route discovery
source routing
backward learning (similar to intra-AS routing)
Dynamic Source Routing (DSR)
Cooperative nodes
Relatively small network diameter (5-10 hops)
Detectable packet error
Unidirectional or bidirectional link
Promiscuous mode (optional)