Ad-hocOn-demandDistanceVector Stephen Walter
Protocol
Improving the
Issues with Wireless Networks
• Expensive• Physically impossible• Setup time• Inflexible to change
Some environments have no existing routers or wired infrastructure
Ad-hoc Solutions• Use existing computers to act as routers
• Traditional routing algorithms no longer work well
• Use protocol to discover the path (routing)
Protocol Classes
• Ready to go• Whole topology• Updates changes
Reactive
• On-demand• Little maintenance• Cell operations
Proactive
Overhead costs
• Bandwidth
• Battery power
• Inflexible
Ad-hoc On-demand Distance Vector (AODV)
Charles E. Perkins, 1999• Reactive protocol• Fast discovery• Loop free• On-demand
AODV Route Discovery
Starting Point
Destination
AODV Route Discovery
AODV Route Discovery
AODV Route Discovery
AODV Route Discovery
AODV Route Discovery
AODV Route Discovery
AODV Route Discovery
AODV Route Maintenance
AODV Route Maintenance
Broken Link in Route
AODV Route Maintenance
AODV Issues• Delay in connections • Floods network• Expensive repairs• System dependant
(long chain)
(simple repair)
Proposed Protocol
Combine successful ideas to build a more effective protocol
• Multi-radio• Multi-path• Hybrid Tiered Structure
Multi-radio
Allows routes to operate without confliction
Requests for longer distances use higher bands
Multi-pathEfficient use of original request flood
•Stable Connections
•Less Rediscovery Requests
•Increased Capacity
Hybrid• Flesh out gaps• Increase performance• Allow seamless transitions between structures
Fixed Connection
Questions