Difference between AODV Routing Protocol and DSR Protocol : Detailed Comparison

Difference between AODV Routing Protocol and DSR Protocol

An ad hoc network or Mobile ad hoc network refers to a network connection established for a single session and does not require a router or a wireless base station. It does not depend on a pre-existing infrastructure such as routers in wired networks or APs in managed wireless networks. This is divided into reactive and proactive routing protocols. This Reactive routing protocol or on-demand routing is further sub divided into two categories:

• AODV Routing Protocol
• DSR Protocol

Introduction to AODV Routing Protocol

Ad-hoc On-Demand Distance Vector (AODV) is a reactive routing protocol where routes are created only when they are required. Main application of AODV is mobile network. It uses routing table setup follows one entry for each destination. Sequence numbers are used to determine an up-to-date path to a destination. Every entry in the routing table having a sequence number. The sequence number act as a route time stamp, ensuring freshness of the route. Upon receiving a RREQ packet, a node compares its sequence number with the sequence number in the RREQ packet. If the sequence number already greater than that in the packet, the existing route is more up-to-date.

Introduction to DSR Protocol (Dynamic Source Routing)

Dynamic Source Routing is an On-Demand routing protocol where the route is calculated only when it is required. Application of DSR is in multi hop ad hoc networks of mobile nodes. DSR’s main feature is self-organized and self-configured network without any central administration and network setup. It uses no periodic routing messages. Thus it reduces bandwidth overhead and conserved battery power and also huge routing updates.

Comparison : DSR vs AODV

• Both are on demand routing protocols.
• AODV works on Hop by Hop routing whereas DSR on source routing.
• In DSR, route cache entries do not have lifetimes whereas AODV route table entries do have lifetimes.
• DSR uses routing cache aggressively and maintains multiple route per destination where as AODV uses one route per destination.
• In DSR, multiple route per destination requires high storage space where as AODV uses very less space because it uses one route per destination.
• DSR does not have any of the mechanism to expire stale route in the cache whereas AODV is more conservative, the fresher route is always chosen.
• Route discovery cycle is very frequent in AODV and less in DSR.
• Both have scalability problem because of routing.
• DSR uses source routing but AODV uses a table driven routing framework and destination sequence to prevent loop and determine route freshness.
• DSR does not rely on any timer based activities but AODV based on timer activities.
• Bandwidth usage is efficient in AODB but DSR does not have this capability.
• In case of AODV, routes in routing table are deleted when not in use even they are valid routes. However, in scenario of DSR routes are still installed in routing table when they are not valid or staled.
• From performance prospective in mobility scenario- AODV is very good, DSR is very poor.

DIFFERENCE BEWEEN AODV AND DSR SUMMARIZED:

TERMS	AODV	DSR
Protocol Type	Hop by Hop routing	Source routing
Route maintained in	Routing table	Routing Cache
Route Discovery	On Demand	On Demand
Multiple route discovery	No	Yes
Multicast	Yes	No
Broadcast	Yes	Yes
Reuse of routing information	No	No
Route reconfiguration	Erase route, than source notification or local route repair	Erase route the source information
Limited overhead	No	Concept of route cache
Advantage	Reduced control overhead	Multiple route reduced bandwidth overhead
Disadvantage	Scalability problem, large delay caused by route discovery process	Scalability problem due to source routing and flooding, large delay
Route Storage Space	Low Storage Space	High Storage Space
Routes in routing table	Deletion of valid link	Usage of invalid link
Bandwidth usage	Efficient bandwidth usage	Waste bandwidth
MAC Overhead	AODV has less normalized MAC overhead	DSR have MAC overhead
Performance in AD hoc network	AODV has better performance in high mobility scenario	DSR have poor performance in high mobility scenario
Route discovery frequency	AODV have very frequent route discovery	DSR have less frequent route discovery
Utilization	Route discovery is on demand, which is more efficient in dynamic nature of mobile ad-hoc network.	Route is only created when required and node utilizes the route cache information efficiently to reduce the overhead and collision.
Routing overhead	AODV has complex routing	DSR has less routing overhead

Download the difference table here.

Conclusion

Analysis on both protocols infers that Packet delivery ratio for AODV is better than DSR in high mobility. AODV has more end to end delay as compared to DSR. Additionally, AODV incurs more routing overhead in contrast to DSR. Finally, energy consumption in DSR is almost constant as we increase the number of nodes which is opposing to AODV which increases as no. of nodes increase.