A short course on GSM

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GSM Foundation Course
• Course Content
Basic Telephony & Cellular
Principal of Cellular Communication
GSM Features
GSM Network Components
GSM Terrestrial Interfaces
Basic GSM Processes
GSM Air Interface
Radio Interface Optimization, Supplementary services & Contemporary Networks

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Service Industry
• Service Provider is not a Equipment Manufacturer.
• The Service Provider has a license to operate in a
geographical boundary (state/circle/ country).
• It buys equipment from OEM Suppliers (Vendors).
• Installs & commissions the equipment thus making
it’s own Network.
• Provides the desired service to it’s subscribers.

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Basic Telephony
•Off Hook
•Dial Tone
•Dialing Digits
•RBT
•Conversation
•Ring
•Off Hook &
Conversation
•Signaling
•Traffic
SWITCH / EXCHANGE

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Wireless Telephony
BSC
BTS BTS
Mobile Subscriber...
MSC

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Wireless Communication
• Alternative means of wireless communication
• Walkie - Talkie
• Pagers
• Trunked private radios
• Mobile Phone - the magic technology that enables
everyone to communicate anywhere with anybody.

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Cellular Communication
• A cellular system links Mobile subscribers to Public
Telephone System or to another Mobile subscribers.
• It removes the fixed wiring used in a traditional
telephone installation.
• Mobile subscriber is able to move around, perhaps can
travel in a vehicle or on foot & still make & receive call.

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Advantage of Cellular Communication
• Mobility
• Flexibility
• Convergence
• Greater QOS
• Network Expansion
• Revenue/Profit

11. WHATIS CELLULAR TELEPHONY ?
CONSIDERATIONS -
FREQUENCY
SUBSCRIBER DENSITY
COVERAGE
Base Station
Base Station
Base Station
Base Station
Base Station
Base Station

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The Cell
• Cellular Radio involves dividing a large service area into
regions called “cells.”
• Each cell has the equipment to switch, transmit and
receive calls.
• Cells - Reduce the need of High powered transmission
• Cells - Conventionally regarded as being hexagonal, but
in reality they are irregularly shaped.
• Cell shape is determined by the nature of the
surrounding area e.g. Hills , tall building etc.

13. The CELL
 What is a cell ?
A cell is a certain area
that can be reached
with one transceiver
or
A small collection of
transceivers on
different channels at a
single base site.
The hexagonal-shaped communication cells are
artificial & are generated to simplify the planning &
design of a cellular network.
BTS

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Coverage & Capacity
• Coverage
• Percentage of the geographical area covered by cellular service where
mobile telephony is available
• Capacity -
• Number of calls that can be handled in a certain area within a certain
period of time.
• Capacity can also refer to the probability that users will be denied
access to a system due to the simple unavailability of radio channels.

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Cells

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Cell Size
• Large Cells
• 35 Km
• Remote Areas
• High Transmission
Power
• Few subscribers
• Small Cells
• Near about 1 KM
• Urban Areas
• Low Transmission
Power
• Many Subscribers