3. CONTENTS
HISTORY
INTRODUCTION
CELLULAR COMPONENTS
GSM COMPONENTS
NETWORK STRUCTURE
SUBSCRIBER IDENTITY MODULE
GSM SECURITY
ADVANTAGES OF GSM
DISADVANTAGES OF GSM
4. HISTORY
The European Conference of Postal and
Telecommunications Administrations
(ECPT) created the Group Special Mobile
(GSM) to develop a standard for a mobile
telephone system that could be used
across Europe.
The first GSM network was launched in
1991 by Radio-Linja in Finland with joint
technical infrastructure maintenance from
Ericsson.
5. INTRODUCTION
GSM is a cellular network, which means
that mobile phones connect to it by
searching for cells in the immediate
vicinity.
Time Division Multiple Access(TDMA)
Frequency Division Multiple
Access(FDMA)
3 billion people across more than 212
countries and territories.
8. Cell Site
Large Cells
• 32 kms
• High Transmission
Power
• Few Subscribers
Smart Cells
• 0.8 kms
• Urban Areas
• Many Subscribers
9. Cell Types
There are five different cell sizes in a GSM network—macro,
micro, pico, femto and umbrella cells.
Macro cells can be regarded as cells where the base station
antenna is installed on a mast or a building above average roof top
level.
Micro cells are cells whose antenna height is under average roof
top level; they are typically used in urban areas.
Picocells are small cells whose coverage diameter is a few dozen
meters; they are mainly used indoors.
Femtocells are cells designed for use in residential or small
business environments and connect to the service provider’s
network via a broadband internet connection.
Umbrella cells are used to cover shadowed regions of smaller cells
and fill in gaps in coverage between those cells.
10. Frequency System
GSM operate on four different frequency
ranges.
GSM operate in 890 MHz - 960 MHz bands.
In GSM network there are two frequencies:-
1. Uplink Frequency (890 MHz – 915 MHz)
2. Downlink Frequency (935 MHz – 960 MHz)
3. Frequency Channel = 124 (200kHz B/W)
11. GSM Network Components
The Mobile Station
The Base Station System
The Network Switching System
12. Mobile Station (MS)
Mobile Equipment(ME)
1. Vehicle Mounted
2. Portable Mobile Unit
3. Handportable Unit
13. Subscriber Identity Module
(SIM)
1. International Mobile Subscriber Identity-IMSI
2. Temporary Mobile Subscriber Identity-TMSI
3. Location Area Identity-LAI
4. Subscriber Authentication Key-KI
5. Mobile Station International Services Digital
Network-MSISDN
14. Base Station System
Connection b/w ME and MSC
Its Components:-
Base Station Controller(BSC)
1. Contains 40 BTSs.
2. Handover phone signal without involving
MSC.
Base Tranreceiver Station(BTS)
Make connection with mobiles
15.
16. The Network Switching
System
Mobile Services Switching Centre-MSC
Home Location Register-HLR
Visitor Location Register-VLR
Equipment Identity Register-EIR
Authentication Centre-AUC
InterWorking Function-IWF
Echo Canceller-EC
17.
18.
19. The network behind the GSM system seen by the
customer is large and complicated in order to provide
all of the services which are required.
The Base Station Subsystem (the base stations and
their controllers).
The Network and Switching Subsystem (the part of
the network most similar to a fixed network). This is
sometimes also just called the core network.
The GPRS Core Network (the optional part which
allows packet based Internet connections).
All of the elements in the system combine to produce
many GSM services such as voice calls and SMS.
21. Subscriber Identity Module
One of the key features of GSM is the
Subscriber Identity Module (SIM),
commonly known as a SIM card.
The SIM is a detachable smart card
containing the user's subscription
information and phonebook. This allows the
user to retain his or her information after
switching handsets
22. GSM SECURITY
GSM was designed with a moderate level of
security.
PIN (Personal Identity Number) Password
PIN2 (Personal Identity Number) Password
PUK (Personal Unlock Keyword) Password
(e.g.,14468400)
23. Call Costs are becoming lower and lower everyday.
Call quality is much more pure and secure in GSM.
More and more value-added services like GPRS,
EDGE etc are coming everyday.
Power is less consumed in GSM handsets compared
to CDMA handsets.
If u have a tri-band GSM phone u can use it in
almost any part of the world.
24. Call costs will still remain higher compared to
CDMA. Roaming costs are much lower in CDMA
compared to GSM.
GSM phones can be tampered with. They have
their unique IMEI number which is used to lock
the phone permanently but now a days
software’s are available which can tamper them
too.
If your SIM is lost then all data is lost unless u
have it stored in the phone’s memory.