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