PRESENTED BY:ANUP KUMAR

ELECTRONICS & COMMUNICATIONYAGYAVALKYA INSTITUTE OF TECHNOLOGY

http://powerpointpresentationon.blogspot.com

Company profile• TODAY’S POSITION OF BSNL:

Today , BSNL is the No. 1 Telecommunication Company and the largest Public Sector Undertaking of India and its responsibilities includes improvement of the already impeccable quality of telecom services, expansion of telecom services in all villages and instilling confidence among its customers.

Company profile• CEO & MD : GOPAL DAS• R&D HEAD : R.L SHARMA• FOUNDED: 19th century, incoprated 2000• HEAD Quarters : New Delhi India • REVENUE : 7.73 Billion us doller(2010)• EMPLOYES : 4,57,000 – march 31, 2010• PRODUCTS: Wireless, Telephone, Interent, etc.• SERVICES : GSM,CDMA,3G,WI MAX AN And

many more.• Website : Bsnl.co.in

What is DWDM• Dwdm is the dense wavelength divison multiplexing

• It is the tecnology which multiplexes multiple carrier signals on a signal optical fiber is called the Dwdm

• Wdwm is the increces of the banwidth of the channel this tecnolgoy is called the Dwdm

Introduction to DWDM• DWDM systems being deployed today can increase

a single fiber’s capacity sixteen fold, to a throughput of 40 Gb/s.

• Dense wavelength-division multiplexing (DWDM) revolutionized transmission technology by increasing the capacity signal of embedded fiber.

• DWDM technology can be applied to different areas in the telecommunication networks, which includes the backbone networks, the residential access networks, and also the Local Area Networks (LANs).

• In the dwdm are three areas, developments in the DWDM-based backbone network are leading the way, followed by the DWDM-based LANs. The development on DWDM-based residential access networks seems to be lagging behind at the current time.

• The multiple channels of information (each having a different carrier wavelength) are transmitted simultaneously over a single fiber.

• The number of wavelength channels is above 20 in a WDM system, it is generally referred to as Dense WDM or DWDM.

Early WDM began in the late 1980s using the two widely spaced wavelengths in the 1310 nm and 1550 nm (or 850 nm and 1310 nm) regions, sometimes called wideband WDM

The early 1990s saw a second generation of WDM, sometimes called narrowband WDM, in which two to eight channels were used. These channels were now spaced at an interval of about 400 GHz in the 1550-nm window.

• By the mid-1990s, dense WDM (DWDM) systems were emerging with 16 to 40 channels and spacing from 100 to 200 GHz. By the late 1990s DWDM systems had evolved to the point where they were capable of 64 to 160 parallel channels, densely packed at 50 or even 25 GHz intervals

Development of DWDM technology

Figure 1 Evolution of DWDM

VARIETIES of WDM• Early WDM systems transported two or four

wavelengths that were widely spaced. WDM and the “follow-on” technologies of CWDM and DWDM have evolved well beyond this early limitation.

• (i) WDM:-Traditional, passive WDM systems are wide-spread with 2, 4, 8, 12, and 16 channel counts being the normal deployments. This technique usually has a distance limitation of less than 100 km.

• (ii) CWDM:- The CWDM grid is made up of 18 wavelengths defined within the range 1270 nm to 1610 nm spaced by 20 nm.

• (iii) DWDM:- Dense WDM common spacing may be 200, 100, 50, or 25 GHz with channel count reaching up to 128 or more channels at distances of several thousand kilometers with amplification and regeneration along such a route.

DWDM System function• It an optical technology used to increase Band width over existing fiber optic

backbones.

• Dense wavelength division multiplexing systems allow many discrete transports channels by combining and transmitting

• In effect, one fiber is transformed into multiple virtual fibers. So, if you were to multiplex 32 STM-16 signals into one fiber, you would increase the carrying capacity of that fiber from 2.5 Gb/s to 80 Gb/s. Currently, because of DWDM, single fibers have been able to transmit data at speeds up to 400Gb/s.

• Dense WDM common spacing may be 200, 100, 50, or 25 GHz with channel count reaching up to 128 or more channels at distances of several thousand kilometers with amplification and regeneration along such a route.

MULTIPLEXING

Fig. 2 Block Diagram of a DWDM System

DWDM SYSTEM COMPONENTS

Figure 3: DWDM System Components

Components:1.Transmitter

1.Multiplexer or demultiplexer

1.Amplifier

1.Optical fiber (media)

1.Receiver

Transmitter• Changes electrical bits to optical pulses

• Is frequency specific

• Uses a narrowband laser to generate the optical pulse

Multiplexer or Demultiplexer• Combines/

separates discrete wavelengths

• Multiplexer i s used to single o/p of multichannel

• Demultiplexer i s used to many o/p of single channel

Amplifier

• Pre-amplifier boosts signal pulses at the receive side

• Post-amplifier boosts signal pulses at the transmit side (post amplifier) and on the receive side (preamplifier)

• In line amplifiers (ILA) are placed at different distances from the source to provide recovery of the signal before it is degraded by loss

• EDFA (Erbium Doped Fiber Amplifier) is the most popular amplifier

Optical fiber (media)• Transmission media to carry optical pulses

• It the used to transmission by the fiber optic

• Many different kinds of fiber are used

Receiver• Changes optical pulses back to electrical bits

• Uses wideband laser to provide the optical pulse

BENEFITS of DWDM• Increases bandwidth (speed and distance)

• Does not require replacement or upgrade their existing legacy systems

• Provides "next generation" technologies to meet growing data needs

• Less costly in the long run because increased fiber capacity is automatically available; don't have to upgrade all the time.

Thank You