1. Ad-hoc On-demand Distance Vector
Improving the
Ad-hoc On-demand Distance Vector
Stephen Walter
Protocol

2. Issues with Wireless Networks
Some environments have no existing routers or wired infrastructure
Expensive
Physically impossible
Setup time
Inflexible to change

3. Ad-hoc Solutions Use existing computers to act as routers
Use protocol to discover the path (routing)
Traditional routing algorithms no longer work well

4. Protocol Classes Proactive Reactive Ready to go Whole topology
On-demand
Little maintenance
Cell operations
Ready to go
Whole topology
Updates changes
Overhead costs
Bandwidth
Battery power
Inflexible

5. Ad-hoc On-demand Distance Vector (AODV)
Charles E. Perkins, 1999
Reactive protocol
Fast discovery
Loop free
On-demand

6. AODV Route Discovery
Destination
Starting Point

7. AODV Route Discovery

8. AODV Route Discovery

9. AODV Route Discovery

10. AODV Route Discovery

11. AODV Route Discovery

12. AODV Route Discovery

13. AODV Route Discovery

14. AODV Route Maintenance AODV Route Maintenance
Broken Link in Route

15. AODV Route Maintenance

16. AODV Issues Delay in connections Floods network Expensive repairs
System dependant
(simple repair)
(long chain)

17. Proposed Protocol
Combine successful ideas to build a more effective protocol
Multi-radio
Multi-path
Hybrid Tiered Structure

18. Multi-radio Allows routes to operate without confliction
Requests for longer distances use higher bands

19. Multi-path Efficient use of original request flood Stable Connections
Less Rediscovery Requests
Increased Capacity

20. Hybrid Flesh out gaps Increase performance
Fixed Connection
Hybrid
Flesh out gaps
Increase performance
Allow seamless transitions between structures

21. Questions