1. Scenario-based Performance Analysis of Routing Protocols for Mobile Ad-hoc Networks
Mobicom ‘99
Per Johansson, Tony Larsson, Nicklas Hedman
POSTECH ANMC Lab. Wonik Kim

2. Contents Description of Protocols Simulation Environment Simulation
Network Simulator / Mobility Extension / Simulation Overview / Modifications
Simulation
Measurement
Mobility Simulation
Average delay / Throughput / Overhead
Summary

3. Introduction Efficiently find routes between two communicating nodes.
Table-Driven Routing Protocols
Destination-Sequenced Distance Vector (DSDV)
Source-Initiated On-Demand Routing
Dynamic Source Routing (DSR)
Ad-Hoc On-Demand Distance Vector Routing (AODV)

4. AODV D S D S D S Route Request Propagation Reverse Path Formation
Forward Path Formation D S

5. AODV Path Maintenance S 1 R 2 4 3’ 3 S 1 R 2 4 3’
The Initial Route 3’ 3
RERR S 1 R 2 4 3’
After Route Reconstruction
Node 3 moves to new location 3’
node 2 notices loss of link, sends link failure to node 1
node 1 forwards link failure to Source
Source reinitiate route discovery, finds new route through node 4

6. DSR N8 N2 N3 N4 N5 N6 N1 N7
N1-N3
N1-N3-N4
N1-N2
N1-N2-N5
N1-N3-N4-N6
N1-N3-N4-N7
Destination
Source
<= Route Record during Route Discovery N8 N2 N3 N4 N5 N6 N1 N7
N1-N2-N5-N8
Destination
Source
Route Reply with the Route Record =>

7. DSDV
Proactive
Each node maintains a routing table that contains the next-hop for, and number of hops to, all reachable destinations
Periodical broadcasts of routing updates
To guarantee loop-freedom, DSDV uses a concept of sequence numbers to indicate the freshness of a route

8. Simulation Environment – Network Simulator
NS-2
It provides substantial support for simulation of TCP, routing, and multicast protocols
C++ & Otcl (Object Tool Command Language)
Otcl
Script
Network
Simulator -2
Output
Data
processing
Network
Animator

9. Simulation Environment – Mobility Extension
Wireless mobility extension developed by the CMU Monarch Projects.
The following features
Node Mobility
Realistic physical layers
MAC
Address Resolution Protocol
Ad-hockey
Radio network interface
Transmission power
Antenna gain & receiver sensitivity
Ad-hoc routing protocols

10. Simulation Environment - Mobility Extension (shared media)
Based on a shared media model (Ethernet in the air)
Mobile Node
Mobile Node
Mobile Node
Channel

11. Simulation Environment - Mobility Extension (mobile node)
Entry
point
Application
Routing
Agent M U X
Link
Layer
MAC
Queue
ARP
Network
Interface
Channel
Propagation
model
Make use of a routing agent for the purpose of calculating routes

12. Simulation Environment – Simulation Overview
Scenario file
the movement pattern of the nodes
Communication file
the traffic in the network
Scenario generation
Output files
Network
Simulator -2
Mobility extension
Data processing
Scenario file
Communication file
Ad-hockey
GnuPlot
Network animator

13. Simulation Environment – Modifications -1
AODV
AODV with only IP-based hello message
AODV with only Link Layer notification of broken links
AODV with both IP-based hello message & Link Layer notification of broken links

14. Simulation Environment – Modifications -2
DSR
Eavesdropping
DSDV

15. Simulation - Measurements
Quantitative metrics
external view vs. internal view
Parameters
Mobility
Offered network load (Packet size, # of connections...)
Network size ( # of nodes, size of the area)

16. Mobility Simulation - Setup
Mobility factors : 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5
speed of a vehicle : the interval 0 to 20m/s

17. Mobility Simulation - Mobility vs. link changes

18. Mobility Simulation - Average delay
AODV
DSR

19. Mobility Simulation - Throughput
AODV
DSR

20. Mobility Simulation - Overhead
AODV
DSR
DSR
AODV

21. Summary mobility simulations
Both DSR and AODV performed quite well for almost all scenarios, while DSDV had serious performance problems
DSR : paths have a limited number of hops
Further work
additional analysis of other proposed protocols
measurements & estimation of power consumption and processing costs
inclusion of QoS mechanisms for real-time & non real-time traffic
evaluation of proposed multicast routing protocols