Dense wavelength division multiplexing

WELCOME

A POWERPOINT PRESENTATION

ON

DENSE WAVELENGTH DIVISIONMULTIPLEXING

--PRESENTED BY

NITESH SRIVASTAVADEPT- ECESEM- 6TH

ROLL- 32

…

WAVELENGTH DIVISION MULTIPLEXING :

• WDM is a technology which multiplexes multiple optical carrier signals on a single optical fiber by using different wavelengths of laser light to carry different signals.

• There are two types of WDM— > Coarse WDM > Dense WDM

WHAT IS DWDM ??

> Dense wavelength division multiplexing (DWDM) is a technology that uses more than eight multiplexed signals to transmit many wavelengths of light simultaneously over a single optical fiber .

HISTORY OF DWDM ::

Late1990’s

Mid 1990’s

Early 1990’s

1980’s

64 to 160 channels in 1550 nm windowNext generation DWDM systemChannel spacing of 0.2 to 0.4 nm

16 to 40 channels in 1550nm windowDWDM (Dense wdm)Channel spacing of 0.8 to 1.6

2 to 8 channels in 1550nm windowPassive (or) 2nd generation WDMChannel spacing of~ 3.2nm

2 channels WWDM (Wideband WDM)1310nm & 1550nm

A DWDM SYSTEM::

*A basic DWDM system contains several main components:

(a) A DWDM terminal multiplexer

(b) An intermediate line repeater

(c) An intermediate optical terminal

(d) A DWDM terminal demultiplexer

(e) Optical Supervisory Channel (OSC)

BLOCK DIAGRAM OF DWDM SYSTEM ::

ITU-TG ::

• ITU standards suggest that the OSC should utilize an OC-3 signal structure, though some vendors have opted to use 100 megabit Ethernet or another signal format.

•Transponders in some systems supporting 40 GHz nominal operation may also perform forward error correction (FEC) via 'digital wrapper' technology, as described in the ITU-TG.709 standard.

•Through ITU-TG.694.1frequency grid , it is easier to integrate WDM with older but more standard SONET/SDH systems.

WAVELENGTH CONVERTING TRANSPONDERS ::

•Wavelength converting transponders translate the transmitted wavelength of a client-layer signal into one of the DWDM system's equivalent internal wavelengths.

•In the mid-1990s,wavelength converting transponders rapidly took on the additional function of signal regeneration. Signal regeneration in transponders quickly evolved through 1R to 2R to 3R .

1R 2R 3R Retransmission Re-time, Re-transmit

Re-time,Re-transmit,Re-shape

RECONFIGURABLE OPTICAL ADD-DROP MULTIPLEXER ::

• Intermediate optical amplification sites in DWDM systems may allow for the dropping and adding of certain wavelength channels. Adding or dropping wavelengths requires manually inserting or replacing wavelength-selective cards.

OPTICAL CROSS CONNECTS::(OXC)

• When the network topology is a mesh ,an additional fibre interconnection device is needed to route the signals from an input port to the desired output port.These devices are called optical crossconnectors(OCXs).Various categories of OXCs include electronic, optical, and wavelength selective devices.

CHANNEL SPACING ::

• The minimum frequency separation between two different multiplexed signals is known as the Channel Spacing. Since the wavelength of operation is inversely proportional to the frequency, a corresponding difference is introduced in the wavelength of each signal.

CATEGORIES OF WAVELENGTH SWITCHES ::

• Non-reconfigurable switch. • Wavelength-Independent Reconfigurable switch.

• Wavelength-Selective Reconfigurable Switch.

• DWDM , ideally it should have additional optical switching capability to implement dynamically reconfigurable interconnections necessary for the next generation systems.

SONET WITH DWDM ::• By using DWDM as a transport for TDM, existing SONET equipment investments can be preserved. Often new implementations can eliminate layers of equipment.

SONETTERMIN

AL

ATMSWITCH

LAYER -3

SWITCH

WDM

OC-n

OC-4

8C

OC-4

8C

FIBER

DWDM-FM ::

• DWDM-FM (95.5 MHz Metro Manila) was a music FM radio station owned by Eagle Broadcasting Corporation in the Philippines. The station's studio was located in EDSA, Quezon City and its transmitter

located at Commonwealth Avenue, Quezon City.

IP OVER DWDM ::* The problem: The explosive growth of the Internet spurred by high speed access networks and flat-rate mobile billing plans has caused ferocious competition in the telecom service provider market.

* Solutions: One potential answer is IP over DWDM.

REQUIRMENTS IN THE METROPOLITAN AREA ::

• The requirements in the metropolitan market may differ in some respects from those in the long-haul network market.

> Some key requirements for DWDM systems in the MAN include the following---- • Multiprotocol support • Scalability • Reliability and availability • Openness (interfaces, network management, standard fiber types,electromagnetic compatibility) • Ease of installation and management • Size and power consumption • Cost effectiveness

VALUE OF DWDM IN METROPOLITAN AREA ::

• It was first deployed on long-haul routes in a time of fiber scarcity. Then the equipment savings made it the solution of choice for new long-haul routes, even when ample fiber was available. Alternatives for capacity enhancement exist, such as pulling new cable and SONET overlays, but DWDM can do more.

WHY DWDM ??

• From both technical and economic perspectives, the ability to provide potentially unlimited transmission capacity is the most obvious advantage of DWDM technology. The current investment in fiber plant can not only be preserved, but optimized by a factor of at least 32. capacity can be obtained for the cost of the equipment, and existing fiber plant investment is retained.

BENEFITS OF DWDM ::

• Capacity increase : Large aggregate transmission capacity.

• Upgradability : Customer growth without requiring additional fiber to be laid.

• Flexibility : Optical Add/Drop Multiplexing (OADM) Optical Cross connect (OXC)

• Scalability : The possibility to add new nodes to the network.

• Network Transparency : Independence of data rate, format & protocols.

REFERENCES :

.www.wikipedia.com

.www.google.com

THANK YOU....

QUERIES??