2. 4th largest telecommunication company in
asia and 7th largest in the world.
Provides GSM and basic telephony service and
first company in India providing 3G.
More than 3 laces of employees, officers and
engineers are working at present.
3. -> WLL (wireless in locked loop)
-> GSM (global system for mobile communication)
-> CDMA (code division multiple access)
-> MTNL ( mahanagar telephone nigam limited)
4. What is WLL?
-Communication system that connects us to PSTN.
- Use Radio Frequency Signals.
- Useful for Subscribers located in pockets.
5. Provides 2 types of services –
(1)Fixed WLL
(2) WLL with portability
Features of WLL –
i) Dynamic STD/ISD locking.
ii) Call Waiting / Call transfer.
iii) Call Forwarding.
iv) STD / ISD call details.
6. - Provided using a telephone instrument.
- FWT will be wall mounted.
-Short cable connected from outdoor
aerial to wall set.
- Wall set powered by an a.c. supply.
7. -Provides portability feature to WLL subscriber.
- This can be done by a portable hand Set which
can be carried in the pocket.
8. History
- Torleiv Maseng is regarded as the father of the GSM
Technology.
- 1989, GSM responsibility was transferred to the
European Telecommunications Standards Institute (ETSI)
- first GSM network was launched in 1991 by Radiolinja in
Finland with joint technical infrastructure maintenance
from Ericsson.
9. • 2G GSM networks operate in the 900 MHz or
1800 MHz bands
• GSM-900 uses 890–915 MHz to send information
from the mobile station to the base station (uplink)
• 935–960 MHz for the other direction (downlink),
• providing 125 RF channels (channel numbers 0
to 124) spaced at 200 kHz. Duplex spacing of 45
MHz is used
10.
11. • MS refers to the physical
phone itself.
• uniquely identified by the
International Mobile
Equipment Identity (IMEI)
number.
• Sim is small smart card that
is inserted into the phone and
carries information specific to
the subscriber
12. • carry out radio communications
between the network and the MS
• handles speech
encoding, encryption, multiplexing
(TDMA), and
modulation/demodulation
•between 1 and 16 Transceivers
(TRX)
13. • allocation of radio channels
•frequency administration
•power and signal measurements
from the MS,
•handovers from one BTS to
another
14. • call routing, call setup, and basic
switching functions
• iner-BSC handoffs as well as
coordinates with other MSC's for
inter-MSC handoffs.
15. • gateway between two
networks
• switch to the Public Switched
Telephone Network (PSTN).
16. • HLR maintains subscriber-
specific information such as the
MSISDN, IMSI, current
location
of the MS, roaming
restrictions,
• VLR is a database that
contains
a subset of the information
located on the HLR
17. • EIR is a database that keeps
tracks of handsets on the network
using the IMEI
• handles the authentication and
encryption tasks for the network
18. ◦ All PSTN applications
Integrated access node
CSNMM - ADSL + Voice
Backward compatible with
CSNMA
CSE
Support for V5.2 for access nodes
Trunk Automatic Exchange (TAX)
International Gateway
Signaling transfer point (STP)
◦ IN
SSP
◦ Mobile applications
GSM /GPR
