GSM and Basics of 3G .Architecture of GSM

1. GSM AND BASICS OF
3G
SUBMITTED BY:
BHANU PRATAP SHARMA
11470102810
ECE-B

2. INTRODUCTION TO GSM
• GSM (Global System for Mobile Communications, is a
standard set developed by the European
counteries.Telecommunications Standards to describe
protocols for second generation (2G) digital cellular
networks
• GSM networks operate in a number of different carrier
frequency ranges with most 2G GSM networks
operating in the 900 MHz or 1800 MHz bands.
• Extended GSM (EGSM) EGSM has 10MHz of bandwidth
on both transmit and receive. Receive bandwidth is from
880 MHz to 890 MHz Transmit bandwidth is from 925
MHz to 935 MHz

3. FEATURES OF GSM
• Compatibility
The need for a common standard for mobile
telecommunications was set up to co-ordinate the
complicated task of specifying the new standardized network.
• Noise Robust
In order to combat the problems caused by noise, GSM uses
digital technology instead of analogue.
• Improved Security
With GSM, both the Mobile Equipment (ME) and Mobile
Subscriber are identified. The subscriber is authenticated by
use of a smart card known as a Subscriber Identity Module
(SIM)

4. GSM Architecture

5. Mobile station
• MS consists of two parts, the Mobile Equipment (ME) and an
electronic ‘smart card’ called a Subscriber Identity module
(SIM).
• Hardware has an identity number associated with it, which is
unique for that particular device and permanently stored in it.
• This identity number is called the International Mobile
Equipment Identity (IMEI)

6. Base Station System (BSS)
• The BSS communicates with the MS over the digital air
interface
• The BSS consists of three major hardware components
• The Base Transceiver Station – BTS
This is the part of the GSM network which communicates with
the MS. The antenna is included as part of the BTS.
• The Base Station Controller – BSC
The BSC as its name implies provides the control for the BSS.
The BSC communicates directly with the MSC. The BSC may
control single or multiple BTS.
• The Transcoder
The Transcoder is used to compact the signals from the MS so
that they are more efficiently sent over the terrestrial
interfaces.

7. Network Switching System
• Main function is to manage communications between the
GSM network and other telecommunications networks.
• The components of the Network Switching System are listed
below:

Mobile Services Switching Centre – MSC

Home Location Register – HLR

Visitor Location Register – VLR

Equipment Identity Register – EIR

8. Mobile Services Switching Centre (MSC)
The functions carried out by the MSC are
Call Processing
Includes control of data/voice call setup, inter-BSS and inter-MSC handovers
and control of mobility management (subscriber validation and location).
Operations and Maintenance Support
Includes database management, traffic metering and measurement, and a
man–machine interface.
Home Location Register (HLR)
The parameters stored in HLR are
•Subscribers ID
•Current subscriber VLR.
•Supplementary services subscribed to.
•Supplementary services information.

9. Visitor Location Register (VLR)
•The VLR provides a local database for the subscribers wherever they are
physically located
•This function eliminates the need for excessive and time-consuming references
to the “home” HLR database.
Equipment Identity Register (EIR)
The EIR database consists of lists of IMEIs (or ranges of IMEIs) organized as
follows:
White List
Contains those IMEIs which are known to have been assigned to valid MS
equipment.
Black List
Contains IMEIs of MS which have been reported stolen or which are to be denied
service for some other reason.
Grey List
Contains IMEIs of MS which have problems (for example, faulty software).

10. GSM Interfaces
• The interfaces comprise all the connections between the GSM
system .
• Um interface- The "air" or radio interface standard that is used
for exchanges between a mobile (ME) and a base station (BTS /
BSC).
• A interface- The A interface is used to provide communication
between the BSS and the MSC.
• B interface- The B interface exists between the MSC and the VLR
• C interface- The C interface is located between the HLR and a
GMSC

11. GSM Channelization
• There are two types of channels in GSM Physical channels and
logical channels.
• Physical Channels
The physical channel is the medium over which the information
is carried, in the case of a terrestrial interface this would be a
cable.
• Logical channels.
The logical channels consist of the information carried over the
physical channels. They are of two types control and traffic
channels.

12. GSM HANDOVER
• One of the key elements of a mobile
phone or cellular telecommunications
system, is that the system is split into
many small cells to provide good
frequency re-use and coverage. However
as the mobile moves out of one cell to
another it must be possible to retain the
connection. The process by which this
occurs is known as handover or handoff.

13. Requirements for GSM
handover
• The process of handover or handoff within any
cellular system is of great importance. It is a
critical process and if performed incorrectly
handover can result in the loss of the call.
• Dropped calls are particularly annoying to users
and if the number of dropped calls rises,
customer dissatisfaction increases and they are
likely to change to another network.

15. HSDPA
HSUPA
• HSDPA provides packet
data support, reduced
delays and a peak raw
data rate (i.e. over the
air) of 14 Mbps.
• The improvement in
speed and latency
reduces the cost per bit .
• Standard values for
HSDPA are 3.6,7.2,14.4
• HSUPA provides
improved uplink packet
support, reduced delays
and a peak raw data rate
of 5.74 Mbps
• The enhanced uplink
increases the data rate
up to 5.8 Mbit/s.
• Standard values for
HSUPA are
384kbps,2mbps,5.76

16. BENEFITS OF HSPA
• Use of higher order modulation
• Shorter Transmission Time
Interval (TTI)
• Use of link adaptation

17. Basics of 3G
• 3G, short for 3rd Generation, is a term used to represent the
3rd generation of mobile telecommunications technology
• 3G finds application in wireless voice telephony, mobile
Internet access, Fixed Wireless Internet access, video calls and
mobile TV.
• The communication spectrum between 400 MHz to 3 GHz was
allocated for 3G. Both the government and communication
companies unanimously approved the 3G standard.

18. FEATURES OF 3G
• Data rates
• Security
• Evolution Of 3GPP and 3 GPP2

19. THANK YOU