The document discusses multi-hopping in wireless networks. Multi-hopping occurs when there is no direct communication link between the source and target, so the signal passes through one or more intermediate nodes. It describes the working of multi-hop networks using an example. There are two main types - mobile ad hoc networks which do not require fixed infrastructure, and multi-hop cellular networks which use relays to improve coverage and throughput. Some applications of multi-hop networks mentioned are battlefield communication, emergency response systems, and cellular networks.

1. Name – Aditya Pandey
Enrollment no. – 04613304409
M.C.A. 4th Sem

2. Contents:-
 Introduction
 Working
 Characteristics
 Types
 Applications
 Future research
 bibliography

3. INTRODUCTION-
What is multi hopping?
 If there is no direct communication link
between the source and the target , it is
possible to pass through one or more
intermediate stages on the way to the
target . This phenomenon known as multi-
hopping.

4. WORKING-
BASE
STATIO
N
MS – Mobile Station

5. Asymmetry
Time – variation
Non - transitivity

6. Time variation
communications may be “time-variant”,
generally due to variability of the
wireless medium, or due to node
mobility.

7. Asymmetry
communications may be “asymmetric”,
often due to variability of the wireless
medium.

8. Non-Transitivity
If A=B, B=C & C=D
It doesn’t mean A=D

9. There are two types of multi-hop
networks which use concept of multi-
hopping,
1.Mobile Ad - Hoc Networks
2.Multi - Hop Cellular Networks

10. Mobile Ad- Hoc Networks(MANETS)
A mobile ad hoc network consists of a
group of mobile nodes that communicate
without requiring a fixed wireless
infrastructure. Communication between
nodes is performed by direct connection or
through multiple hop relays.

11. Multi-Hop Cellular Networks
A promising solution to the problem of
improving coverage and throughput is the
use of relays.
The use of relays, though, impacts almost
every aspect of cellular system design and
optimization including: scheduling, handoff.

12. Some of the applications are given as,
 Battle-field Communication
 Emergency First Response
 Public Safety system
 Cellular Networks
 In Organizations

13. Emergency first response

14. Battle field communication

15. Public safety system

16. In cellular networks
Base station

17. In organizations

18.  In fourth generation mobile networks
 In mobile computing
 In modulation
 In handoff
 In scheduling

19.  Minimal security -
Due to transfer of information from
source to destination through several nodes

20.  Difficulty in Re-positioning –
At the time of HANDOFF on shifting from
one node to another node

21.  Slower than Wi-Fi –
WiFi - 54+ mbps
WiFi(Ad-Hoc Mode) – 11 mbps

22.  Range limitation-
Ad-hoc networks has a range limit, in
cellular networks it of 30 – 40 mtr

23. Partial
B
overlap- A
In it the coverage
C D
area of nodes partially
overlap, this
phenomenon produce
redundancy at the
time of Handoff.

24. Hidden node problem-
Hidden nodes in a wireless network
refer to nodes that are out of range of other
nodes or a collection of nodes and still
communicates
A S B

25. 
Wireless irregularities –
partial overlap causes communication to
be non-transitive and/or asymmetric, this
produce wireless irregularities.

26. http://users.ece.utexas.edu/~rheath/re
search/multihop/ofdm.php
Computingunplugged.com
Wikipedia.org
Google.co.in/images