The document discusses ad hoc networks, defined as infrastructure-less networks formed by wireless devices enabling anytime and anywhere computing. It highlights various routing protocols such as AODV, DSDV, and DSR, along with the concept of Mobile Ad Hoc Networks (MANET) and Vehicular Ad Hoc Networks (VANET). Additionally, it outlines the advantages of ad hoc networks, including independence from central administration and scalability, while also mentioning potential disadvantages such as performance issues and latency in large networks.

2. The Need Of Time.

3. Preparatory

4. Ad-hoc network
 Ad hoc -- a Latin phrase which means "for this
purpose".
 The rapid growth of Internet
 Today’s society with the development of mobile
devices it has become important to stay online all the
time.
 Also called mesh networks.

5. Defination:
 It is defined by the manner in which the network
nodes are organized to provide pathways for data to be
routed from the user to and from the desired
destination

6. Ad-hoc network
 A network without any base stations “infrastructure-
less” or multi-hop
 A collection of two or more devices equipped with
wireless communications and networking capability
 Supports anytime and anywhere computing

7. Comparison

8. Routing
 Selection Criteria
 Routes are preferred if the sequence numbers are newer
 If the sequence numbers are the same, the one with
better metric is preferred
 Requirements
 Simple, reliable and efficient
 Distributed but lightweight in nature
 Quickly adapts to changes in topology

9. Ad hoc protocols
 Table-Driven Routing Protocols
 Destination-sequenced Distance-vector (DSDV)
 Source-Initiated On-Demand Routing Protocols
 Ad-hoc On-demand Distance Vector (AODV)
 Dynamic Source Routing
(DSR)

10. Ad-hoc On-demand Distance
Vector (AODV)
 It belongs to the class of Distance Vector Routing
Protocols (DV).
 Hop-by-hop routing
 Source sends request to neighbors
 Each neighbor does so until reach the destination
 Destination node sends reply follow the reverse path
 Source doesn’t put whole path but only next hop addr
in outgoing packets

11. Destination-sequenced Distancevector (DSDV)
 Effective for creating ad-hoc networks for small
populations of mobile nodes.
 Also requires each mobile node to maintain a complete
list of routes one for each destination within the adhoc network.
 Link breakages are reported immediately and routes
are quickly reestablished

12. Dynamic Source Routing (DSR)
 Source broadcasts request through the network.
 Intermediate nodes add its address to request and
continue broadcasting until reply received.
 Full path chosen by source and put into each packet
sent.
 Minimum node cost to find the optimal paths

13. Mobile Ad Hoc Networks (MANET)
 It is a kind of network in which all the nodes can move
randomly.
 It is more rigorous than that of traditional network
 It is a self-configuring infrastructureless network of
mobile devices connected by wireless links.

14. Mobile Ad Hoc Networks (MANET)
 MANETs are a kind of wireless ad hoc networks that
usually has a routeable networking environment on
top of a Link Layer ad hoc network.

15. Vehicular Ad Hoc Networks
(VANET)
 OBU (On-Board Units)
–communication devices mounted on vehicles
 RSU (Road Side Units)
–communication units located
aside the roads
 OBU used to communicate with
other vehicles or RSUs
 RSUs connect with application
servers and trust authorities

16. Applications

17. Applications

18. Search & Rescue /
Emergency Services

19. Advantages

20. Advantages
Independence from central network administration
Self-configuring, nodes are also routers
Self-healing through continuous re-configuration
Scalable: accommodates the addition of more nodes
Flexible: similar to being able to access the Internet
from many different locations

21. Disadvantages
 Each node must have full performance
 Throughput is affected by system loading
 Reliability requires a sufficient number of available
nodes. Sparse networks can have problems
 Large networks can have excessive latency (high
delay), which affects some applications

22. Advantages
Present
Applications
Future
Applications
NEED OF THE
TIME