HISTORY OF BSNL
Firstly post and telegraph department
came into existence in 1980.
First exchange in rajasthan was of 25 lines.
Control of Ajmer was upto Udaipur, Agra and
In 1985, post and telegraph seperated into
two different departments i.e. Department of
Post and Department of Telegraph.
REACHES TO EXCHANGE
Each subscriber who wants to contact
The handset divided into two main parts .
The line chord is connected to the handset
and reach to a black box known a
Through the rosette two wires comes out
which is connected with the WINDOW
After that they reach the DP i.e. the
On DP the wires comes in the form of pair . One I
DP 20 wires can be connected from different
DP must be grounded . DP is a box which is
installed on a petlar
After DP , there is a cabinet which is in the form
of large box and which is kept in a large area
which consists of approximately one thousand
pair of wires .
And then it connected to the another type of box
this is called Main Distribution Frame
– Worldwide Interoperability for Microwave Access
– Is a certification mark for products that pass
conformity and interoperability tests for the IEEE
– provides wireless data over long distances in a
variety of ways, from point-to-point links to full mobile
cellular type access
– Faster than broadband service
– Not having to lay cables reduces cost
– Easier to extend to suburban and rural areas
• Broad coverage
– Much wider coverage than WiFi hotspots
Two forms of wireless service
• Line-of-sight service
– Higher frequencies, lots more bandwidth
– 30-mile radius
– A small antenna on a computer connects to the tower
– Uses 2 GHz to 11 GHz frequency range
– Limited to a 4-to-6 mile radius
• BASE STATION (BS):
The BS is responsible for providing the air interface to the MSS.
• ACCESS SERVICE NETWORK GATEWAY (ASN-GW):
The ASN gateway typically acts as a layer 2 traffic aggregation points within
an ASN. Additional functions include intra-ASN location management and
paging, and admission control, caching of subscriber profiles and encryption
• CONNECTIVITY SERVICE NETWORK (CSN):
•The CSN provides connectivity to the Internet, ASP, other public
networks, and corporate networks. The CSN is owned by the NSP and
includes AAA servers that support authentication for the devices, users,
and specific services.
• According to WiMAX Forum it supports 5 classes of
1. Multi-player Interactive Gaming.
2. Video Conference
3. Streaming Media
4. Web Browsing and Instant Messaging
5. Media Content Downloads
Broadband connectivity as defined in Broadband
policy-2004 is an “always on” data connection that is
able to support interactive services including
Internet access and has the capability of minimum
download speed of 256 kbps to an individual
subscriber from the POP of the service provider
Internet v Broadband Sub’s in India
2005 2007 2010
FIBER OPTICAL TRANSMISSION
A Widely Used Communication Medium Based on TIR
Information (Voice, Data Or Video) Is Transmitted In The Form Of Light
FIG. COMMUNICATION THROUGH OPTICAL FIBRE
Light at less than
critical angle is
absorbed in jacket
Light is propagated by
total internal reflection
Fig. Total Internal Reflection in an optical Fibre
ARCHITECTURE OF FIBER AND IT’S
ADVANTAGES OF FIBER
High Speeds – Up To The Gigabits
Signals Can Be Transmitted At Larger Distances Without
The Need Of Repeaters
Greater Resistance To Electromagnetic Noise
GSM Network Architecture
CELLULAR MOBILE CONCEPTS
WHAT IS A CELL ?
• A base station (transmitter) having a number of
RF channels is called a cell
• Each cell covers a a limited number of mobile
subscribers within the cell boundaries
( Coverage area)
• Typical Cell Radius Aprrox = 30 Km (Start up)
Main type of telecommunication services:
Available to all subscribers to a mobile network.
e.g. voice telephone calls.
Additional services that are available by subscription
e.g. Call forwarding.