1. Cellular
Networks
NAME- ADITYA PANDEY
ENROLL. NO.- 04613304409
1

2. CONTENTS
Introduction
Working
Benefits
Characteristics
Movement From Cell To Cell
Mobile Phone Networks
Future Scope
Bibliography
2

3. INTRODUCTION
•A cellular network is a radio network made up of
a number of radio cells (or just cells) each served
by at least one fixed-location transceiver known as
a cell site or base station.
3

4. Example
An example of a simple non-telephone cellular
system is an taxi driver's radio system where the taxi
company has several transmitters based around a city
that can communicate directly with each taxi.
4

5. WORKING
MSMobile station; BSTBase station transceiver; MSCMobile switching center; BSCBase station controller; PSTNPublic
switched telephone network
5

6. BENEFITS
More capacity due to spectral reuse
Lower transmission power due to smaller
transmitter/receiver distances
reduced power usage
larger coverage area
reduced interference from other signals
6

7. CHARACTERISTICS
PAGIN
G
• Paging takes place by sending the broadcast message to
all of the cells.
• In mobile telephony systems, the most important use of
broadcast information is to set up channels for one to one
communication between the mobile transceiver and the
base station.
• Paging messages can be used for information transfer.
7

8. FREQUENCY REUSE
•FDMA
•Frequency Division Multiple
Access or FDMA is a channel
access method used in
multiple-access protocols as a
channelization protocol.
•FDMA gives users an
individual allocation of one or
several frequency bands,
or channels. Multiple Access
systems coordinate access
between multiple users.
8

9. •CDMA
• Code division multiple
access (CDMA) is a channel
access method utilized by various
radio communication
technologies.
• It should not be confused with
the mobile phone standards
called cdmaOne and CDMA2000
(which are often referred to as
simply "CDMA"), which use
CDMA as an underlying channel
access method.
9

10. • TDMA
• Time division multiple access. A method of digital wireless
communications transmission that allows a large number of
users to access (in sequence) a single radio frequency
channel without interference by allocating unique time slots
to each user within the channel. Each frequency is broken
into time slots through which bits of data flow.
• TDMA is used in second generation wireless phone systems,
such as GSM and TDMA.
• TDMA cannot be used to separate signals from one cell to
the next since the effects of both vary with position and this
would make signal separation practically impossible.
• Time division multiple access, however, is used in
combination with either FDMA or CDMA in a number of
systems to give multiple channels within the coverage area
of a single cell.
10

11. MOVEMENT FROM CELL TO CELL &
HANDOVER
•RADIO TAXI NETWORK
•In a primitive taxi system, when the taxi moved away from a
first tower and closer to a second tower, the taxi driver
manually switched from one frequency to another as needed.
If a communication was interrupted due to a loss of a signal,
the taxi driver asked the base station operator to repeat the
message on a different frequency.
11

12. MOVEMENT FROM CELL TO CELL &
HANDOVER
•CELLULAR NETWORK
•In a cellular system, as the distributed mobile transceivers
move from cell to cell during an ongoing continuous
communication, switching from one cell frequency to a
different cell frequency is done electronically without
interruption.
•This is called the handover or handoff.

13. MOBILE PHONE NETWORKS
 The most common example of a cellular network is a mobile
phone (cell phone) network.
 A mobile phone is a portable telephone which receives or makes calls
through a cell site (base station), or transmitting tower.
 Since almost all mobile phones use cellular technology,
including GSM, CDMA, and AMPS (analog), the term "cell phone" is
in some regions, notably the US, used interchangeably with "mobile
phone".
 However, satellite phones are mobile phones that do not
communicate directly with a ground-based cellular tower, but may do
so indirectly by way of a satellite.
13

14. MOBILE PHONE NETWORKS
(Contd.)
 There are a number of different digital cellular technologies,
including:
 Global System for Mobile Communications (GSM)
 General Packet Radio Service (GPRS)
 Code Division Multiple Access (CDMA)
 Evolution-Data Optimized (EV-DO)
 Enhanced Data Rates for GSM Evolution (EDGE or GSM EDGE)
 3GSM
 Digital Enhanced Cordless Telecommunications (DECT)
 Digital AMPS (IS-136/TDMA)
 Integrated Digital Enhanced Network (iDEN).

15. CDMA
 Interim Standard 95 (IS-95) is the first CDMA-based digital cellular
standard pioneered by Qualcomm. The brand name for IS-95
is cdmaOne.
 It is a 2G Mobile Telecommunications Standard that uses CDMA,
a multiple access scheme for digital radio, to send voice, data and
signaling data (such as a dialed telephone number) between
mobile telephones and cell sites.
 CDMA or "code division multiple access" is a digital radio system that
transmits streams of bits (PN codes).
 CDMA permits several radios to share the same frequencies.
 Unlike TDMA "time division multiple access", a competing system
used in 2G GSM, all radios can be active all the time, because network
capacity does not directly limit the number of active radios.
15

16. CDMA (Contd.)
 Since larger numbers of phones can be served by smaller numbers of
cell-sites, CDMA-based standards have a significant economic
advantage over TDMA-based standards that used frequency-division
multiplexing.
16

17. GSM
 GSM (Global System for Mobile communications: originally
from Groupe Spécial Mobile) is the most popular standard
for mobile phones in the world.
 Its promoter, the GSM Association, estimates that 80% of the global
mobile market uses the standard. GSM is used by over 3 billion people
across more than 212 countries and territories.
 GSM differs from its predecessors in that both signaling and speech
channels are digital, and thus is considered a second generation (2G)
mobile phone system.
 This has also meant that data communication was easy to build into
the system. GSM EDGE is a 3G version of the protocol.
17

18. FUTURE SCOPE
 Next Generation Mobile Networks (NGMN) Ltd. - Consortium with
partnership of major mobile operators
 Recommendations without specific technology prescriptions
 Target to establish performance targets, recommendations and
deployment scenarios for future wide-area mobile broadband
network packet switched core.
 The architecture intended to provide a smooth migration of existing
2G/3G networks towards an IP network that is cost competitive and
has broadband performance.
 Multi-hopping Networks.
18

19. BIBLIOGRAPHY
www.google.com
www.wikipedia.org
http://www.acm.org/crossroads/xrds7-2/cellular.html
19

20. Thank You
20