The document presents a detailed overview of cellular systems, emphasizing their wireless communication capabilities and network structure divided into cells with base transceiver stations. It discusses the evolution of mobile phone generations, the features and functionality of cellular systems, and the distinction between circuit-switched and packet-switched systems. Additionally, it outlines the components of both analog and digital cellular systems, including their subsystems and operational functions.

1. Submitted to
Er. Suryakant Soni
Faculty of engineering and technology
M.G.C.G.V. Chitrakoot, Satna
(M.P.) – 485334
Submitted by
Name - Shubham Mishra
Roll N. - 5
Branch- I.T.
Semester- 6th
Date- 23/03/2018
Presentation on
Topic- Basic Cellular System

2. What is cellular system
A cellular system is a communication
network where the last link is
wireless. The network is distributed
over land areas called cells, each
served by at least one fixed-
location transceiver, but more
normally three cell sites or base
transceiver stations. These base
stations provide the cell with the
network coverage which can be used

3. Generations of cellular system
There is a lot of talk about the mobile phone generations. Each mobile phone
generation had its own aims and was able to provide different levels of
functionality.

5. Features of cellular systems
Wireless Cellular Systems solves the problem of spectral congestion and increases
user capacity. The features of cellular systems are as follows −
Offer very high capacity in a limited spectrum.
Reuse of radio channel in different cells.
Enable a fixed number of channels to serve an arbitrarily large number of users
by reusing the channel throughout the coverage region.
Communication is always between mobile and base station (not directly between
mobiles).
Each cellular base station is allocated a group of radio channels within a small
geographic area called a cell.
By limiting the coverage area to within the boundary of the cell, the channel
groups may be reused to cover different cells.
Keep interference levels within tolerable limits.
Frequency reuse or frequency planning.

6. Shape of cells
The coverage area of cellular networks are divided into cells, each cell
having its own antenna for transmitting the signals. Each cell has its
own frequencies.
Square - A square cell has four neighbors at distance d and four at
distance Root 2 d
 Better if all adjacent antennas equidistant
 Simplifies choosing and switching to new antenna
Hexagon - A hexagon cell shape is highly recommended for its
easy coverage and calculations. Provides equidistant antennas
 Distance from center to vertex equals length of side

7. Basic cellular systemsThere are two basic cellular systems
1. Circuit-switched system
2. Packet-switched system.
1.Circuit-Switched Systems - In a circuit-
switched system, each traffic channel is
dedicated to a user until its cell is terminated.
We can further distinguish two circuit-
switched systems: one for an analog system
and one for a digital system.
A. Analog cellular system -
consists of three subsystems: a mobile unit, a
cell site, and a mobile telephone switching office
(MTSO), with connections to link the three
subsystems. The MTSO is the heart of the
analog cellular mobile system. Its processor
provides central coordination and cellular

8. The cellular switch, which can be either analog or digital, switches
calls to connect mobile subscribers to other mobile subscribers and
to the nationwide telephone network. It uses voice trunks similar to
telephone company interoffice voice trunks. It also contains data
links providing supervision links between the processor and the
switch and between the cell sites and the processor. The radio link
carries the voice and signaling between the mobile unit and the cell
site. The high-speed data links cannot be transmitted over the
standard telephone trunks. Microwave radio links or T-carriers carry
both voice and data between cell site and the MTSO.
B. Digital Systems - A basic digital system consists of four
elements: mobile station, base transceiver station (BTS), base
station controller (BSC), and switching subsystem.

9. (SIM). SIM contains all subscriber-specific data stored on the MS side.
 BTS: Besides having the same function as the analog BTS, it has the
Transcoder/Rate
Adapter Unit(TRAU), which carries out coding and decoding as well as rate
adaptation
in case data rate varies.
 BSC: A new element in digital systems that performs the Radio Resource (RR)
management for the cells under its control. BSC also handles handovers, power
management time and frequency synchronization, and frequency reallocation
among BTSs.
 Switching subsystems:
a. MSC
b. VLR
c. HLR
d. AUC
e. EIR
f. IWF
g. EC
h. XC

10. RNC: (radio network controller): controls the radio resources of the node bs that are connected to
it. Its function is similar to BSC A device PCU (packet control unit) converts the data stream into
packet format.
Rns (radio network subsystem): it consists of rnc and node b. UTRAN consists of two or more
RNS.
Sgsn (service gprs support node): analogous to msc/vlr in the circuit-switched system. This
includes mobility management, security, and access control functions. It interfaces to HLR.
Ggsn (gateway gprs support node): the point of interface with external packet data networks such
as the internet.
Ms: provides the voice and packet data services. It is also called UE (user equipment).
Cgf (changing gateway function): mainly for billing.
.

11. Thanky
ou