Need: Access computing and communication services, on the move

Infrastructure-based Networks◦ traditional cellular systems (base station infrastructure)

Wireless LANs◦ Infrared (IrDA) or radio links (Wavelan)◦ very flexible within the reception area; ad-hoc networks possible◦ low bandwidth compared to wired networks (1-1000 Mbit/s)

Ad hoc Networks◦ useful when infrastructure not available, impractical, or expensive◦ military applications, rescue, home networking

Wireless Networks

Host movement frequent Topology change frequent

No cellular infrastructure. Multi-hop wireless links.

Data must be routed via intermediate nodes.

Mobile Ad Hoc Networks (MANET)

A B AB

Setting up of fixed access points and backbone infrastructure is not always viable◦ Infrastructure may not be present in a disaster area or

war zone◦ Infrastructure may not be practical for short-range

radios; Bluetooth (range ~ 10m)

Ad hoc networks:◦ Do not need backbone infrastructure support◦ Are easy to deploy◦ Useful when infrastructure is absent, destroyed or

impractical

Why Ad Hoc Networks ?

ISSUES IN PROVIDING QOS IN MANET Node Mobility Unpredictable link property Security Route Maintenance Finite Battery Life

No base station. No fixed infrastructure.

Traditional fixed networks routing schemes are not effective.◦ E.g. Link state and distance vector routing algorithms

MANET nodes cooperate to provide routing service.◦ A node communicates directly with nodes in wireless

range.◦ For all other destinations, a dynamically determined

multi-hop route through other nodes.◦ Rely on each other to forward packets to their

destination.

ROUTING IN MANET

A

B

C

E

D

G

H

F

A

A

A-B

A-C

A-C-E

A-C-EA-C-E

A-B-D

A-B-D-GA-B-D-GA-B-D-G

Route Discovery

A-B-C

A-B-C

Route Request (RREQ)

Route Reply (RREP)

Route Discovery is issued with exponential back-off intervals.

Initiator ID

Initiator seq#

Target ID

Partial route

RREQ FORMAT

Route Discovery: at source AA need to send to

G

Lookup Cache for route A to G

Route

found?

Start Route Discovery Protocol

Continue normal

processing

Route Discovery finished

Packet in

buffer?

Send packet to next-hopdon

e

Buffer

packet

no

Write route in packet header

yes

yes

no

wait

A

B

C

E

D

G

H

F

G

RERRRERR

Route Cache (A)G: A, B, D, G G: A, C, E, H, GF: B, C, F

Route Maintenance

OVERVIEW OF ADHOC ROUTING PROTOCOLS

AODV = Ad Hoc On-demand Distance Vector Source floods route request in the network. Reverse paths are formed when a node hears a

route request. Each node forwards the request only once

(pure flooding).

AODV Routing Protocol

A

S EF

B

C

G D

Uses hop-by-hop routing. Each node forwards the request only once (pure flooding). Reverse paths are formed when a node hears a route

request.

AODV Route Discovery

A

S EF

B

C

G D

Route reply is forwarded via the reverse path … thus forming the forward path.

The forward path is used to route data packets.

AODV Route Discovery

A

S EF

B

C

G D

13

Dynamic Source Routing(DSR)

The protocol consists of three major phases: Route Discovery, Route Reply, Path Establishment.

When a mobile node has a packet to send to some destination, it first consults its route cache to check whether it has a route to that destination.

If it is an un-expired route, it will use this route. If the node does not have a route, it initiates route

discovery by broadcasting a Route Request packet. This Route Request contains the address of the

destination, along with the source address.

Route Discovery in DSR

B

A

S EF

H

J

D

C

G

IK

Z

Y

Represents a node that has received RREQ for D from S

M

N

L

B

A

S EF

H

J

D

C

G

IK

Z

Y

M

N

L

[S,E]

[S,C]

Route Discovery in DSR

B

A

S EF

H

J

D

C

G

IK

Z

Y

M

N

L

RREP [S,E,F,J,D]

Represents RREP control message

Route Reply in DSR

B

A

S EF

H

J

D

C

G

IK

Z

Y

M

N

L

DATA [S,E,F,J,D]

Packet header size grows with route length

Data Delivery in DSR

Based on minimizing the amount of power required to get a packet from source to destination .

Where p(i,i+1) is power expended for transmitting or receiving between two consecutive nodes i and i+1.

MTPR reduces overall transmission power consumed per packet but doesn’t affect the lifetime of each node.

Minimum Total Transmission Power Routing (MTPR)

Aug Sep

Oct Nov Dec Jan Feb March April

Literature Review

Publishing Research PaperSoftware Study

Implementation

Publishing Research Paper

Timeline

[8]L. Viennot, P. Jacquet, and T. H. Clausen, "Analyzing Control Traffic Overhead versus Mobility and Data Traffic Activity in Mobile Ad-Hoc Network Protocols", Wireless Networks, Vol. 10, Issue 4, pp. 447-455, July 2004

QualNet Simulator   [9]J. Heidemann and N. Bulusu et al. , "Effects of detail in Wireless network Simulation", In Proceedings of

the SCS Multiconference on Distributed simulation",pp 3-11, January 2001.   [10]C. Perkins, E. Royer, and S. Das "Ad hoc on demand Distance vector (AODV) routing". IETF RFC No. 3561,

July 2003 [11]Haas, Zygmunt J. , Pearlman, Marc R. , Samar, P. Interzone Routing Protocol (IERP), June 2001, IETF

Internet Draft, draft- ietf-manet-ierp-01. txt