SUMMER TRAINING
HELD AT BSNL
Aditya Dandotia
INTRODUCTION:
•Bharat Sanchar Nigam Limited (abbreviated BSNL)is an
Indian state owned telecommunications company
headquartered in New Delhi. It is the largest provider of fixed telephony and fourth largest mobile
telephony provider in India, and is also a provider of broadband services.
•Technological developments in the field of
telecommunication in India have been taking place at much faster as per the global trend. Particularly during last three years.
•There has been a major transformation in the switching
SERVICES
Universal Telecom Services
Cellular Mobile Telephone Services WLL-CDMA Telephone Services
Internet
Intelligent Network (IN)
3G
IPTV FTTH WiMax
OVERVIEW OF TELECOMMUNICATION
Telephone is a telecommunication device that is used to transmit and receive electronically or digitally
encoded speech between two or more people conversing.
Telecommunication networks carry information signals among entities , which are geographically apart.
The telecommunication links and switching were mainly designed for voice communication
TELEPHONE EXCHANGE
Telephone exchange is a hub to which all subscribers are connected.
For smooth working of exchange following unit are very important
1.Computer Unit 2.Power Supply 3.AC
Computer Unit: - it deals with additional services of the exchange to the customers with the help of computers. Power Plant:- to feed proper power supply to exchange AC Plant: - to maintain the continuous temperature + or – 2 degree Celsius to the digital switch (exchange).
MDF(MAIN DISTRIBUTION FRAME)
The fault of telephone number is removed in the MDF; it is called as Fault Remove Section.
These testing are T.T.Y. testing, Group testing, etc. The telephone numbers are also disconnected in the MDF because of some specific reason
ORGANISATION OF THE MDF PARTS:-
Horizontal side Vertical side
HORIZONTAL SIDE
It is subdivided into two parts Exchange side
Line side
Description of the horizontal side:-
Rack-On the rack, the tags are situated. One rack is having eight tags.
WEDGE:-If we want to disconnect any two numbers then we insert a wedge between subscriber side and exchange side. Here wedge works as insulator made of plastic.
VERTICAL SIDE
The vertical side connected to the underground cable. This cable is having 100 pairs.
These pair is distributed when we allot the telephone number to the subscriber.
Vertical side is again subdivided in two parts:
One part is connected with the horizontal side and another with the subscriber line by using 100 pair underground cable.
NIB(NETWORK INTERNET BACKBONE)
Networking is a key component of any Internet Services Provider (ISP) operations.
The Internet Backbone refers to the principal data routes between large, strategically interconnected networks and core routers in the Internet.
BASIC BLOCKS OF NIB
1.MDF 2.Router 3.DSLAM 4.BNG
DSLAM (DIGITAL SUBSCRIBER LINE ACCESS
MULTIPLEXER)
Maximum capacity of each DSLAM is 480 kbps Minimum capacity of each DSLAM is 120 kbps 480 kbps DSLAM has 16 cards, each card has
48pairs of broad band customers
One end of the DSLAM is connected to MDF
PULSE CODE MODULATION(PCM)
Pulse Code Modulation (PCM) converts analog
signals to a digital format(signal).This process has four major steps.
1.Filtering 2.Sampling 3.Quantizing 4.Encoding
OPTICAL FIBRE
The latest technology that we use today is optical
fibre communication system.
In this system sound energy is converted to light
which is transmitted over optical fibres. This has 99% efficiency.
ADVANTAGES OF FIBRE OPTICS :
Fibre Optics has the following advantages :
• SPEED: Fiber optic networks operate at high speeds - up into the gigabits
• BANDWIDTH: large carrying capacity
• DISTANCE: Signals can be transmitted further without needing to be "refreshed" or strengthened.
• RESISTANCE: Greater resistance to electromagnetic noise such as radios, motors or other nearby cables.
• MAINTENANCE: Fiber optic cables costs much less
OVERVIEW OF BROADBAND TECHNOLOGY
Broadband is the nonspecific term for high-speed digital Internet access.
Communication of data with different throughput is feasible by following technologies:
Narrow Band 2.4Kbps – 128Kbps. Broadband 256Kbps – 8000Kbps. LAN 1000 – 100Mbps.
Broadband communication technology can be divided broadly in to categories:
Wire line Technology. Wireless Technology.
Wireline Technologies include:
Digital Subscriber Lines (DSL) on copper
loop.
Optical Fibre Technologies.
Cable TV Networks.
WIRELESS TECHNOLOGIES INCLUDE:
Satellite Media
Terrestrial Wireless
3G Mobile
Wi-Fi (wireless Fidelity)
Wi Max.
GSM
Network and switching subsystem
NSS is the main component of the public mobile network GSM
switching, mobility management, interconnection to other networks,
system control
Components
Mobile Services Switching Center (MSC)
controls all connections via a separated network to/from a mobile terminal within the domain of the MSC - several BSC can belong to a MSC
Databases (important: scalability, high capacity, low delay) Home Location Register (HLR)
central master database containing user data, permanent and semi-permanent data of all subscribers assigned to the HLR (one provider can have several HLRs)
Visitor Location Register (VLR)
local database for a subset of user data, including data about all user currently in the domain of the VLR
GSM : (SYSTEM ARCHITECHTURE)
This system structured hierarchically as shown:
It consist of one administrative region, which is assigned
to a MSC(Mobile Switching Center).
Each administrative Region is made up of atleast one
Location Area(LA). LA is also called the visited area.
An LA consists of several cell groups.
Each cell group is assigned to a base station
controller(BSC).
OPERATION SUBSYSTEM
The OSS (Operation Subsystem) enables centralized operation,
management, and maintenance of all GSM subsystems
Components
Authentication Center (AUC)
generates user specific authentication parameters on request of a
VLR
authentication parameters used for authentication of mobile
terminals and encryption of user data on the air interface within the GSM system
Equipment Identity Register (EIR)
registers GSM mobile stations and user rights
stolen or malfunctioning mobile stations can be locked and
sometimes even localized
Operation and Maintenance Center (OMC)
different control capabilities for the radio subsystem and the network
TEMPORARY DATA PERMANENT DATA
- Temporary Subscriber Identity Permanent Subscriber
Identity
- Current Location Key/Algorithm for Authentication.
- Ciphering Data
Provides access to the GSM n/w Consists of
Mobile equipment (ME)
THE GSM NETWORK ARCHITECTURE
Time division multiple access-TDMA
124 radio carriers, inter carrier spacing
200khz.
890 to 915mhz mobile to base - UPLINK
935 to 960mhz base to mobile - DOWNLINK
