dwdm applications

DWDM stand for dense wavelength division multiplexing. Hence dense means the wavelength channel is very narrow and close to each other. Here this article gives the application of DWDM to know more details about it.

• It can be used for signal transmission
• It is ready to make for long distance, Telecommunication operator that use either point to point or ring topology 
• Utilize the existing thin fiber
• Building or expanding network
• The transparency of the DWDM system to  various bit-rate and protocols
• Network wholesalers can lease capacity rather than entire fiber cable

WDM drivers

WDM driver is classified into three types :

• Bus driver
• Function driver
• Filter driver

Function driver :

• A function driver is a specific individual device, such as a printer.

Bus driver :

• Bus driver uses individual buses like PCI, SCSI, and USB, adapter or bridges. It is reported to the child device that is connected to the bus.

Filter driver :

•  It is I/O request for a device, which is a class of device or bus device.

Advantages and disadvantages of SONET

SONET has commonly transmitted data at speed between 155 megabits per second and 2.5 gigabits per second. To the build these high bandwidth data streams, for SONET multiplexer techniques together channels having bandwidth as low as 64-kilobits per second into data frames sent at fixed intervals. So now let us check out the advantages and disadvantages of SONET to know more details about SONET.

Advantages of SONET :

• Reduced cost
• It offers network survivability features
• It is compatible with legacy and future network
• Very high efficiency
• Allows transportation of all  forms of traffic
• Standard optical interference
• De-multiplexing is easy
• Remote operation capabilities. remotely provisioned, tested, inventoried, customized and also reconfigured
• Can we used in SONET networks for fast restoral and protection
• Out of band management system

Disadvantages of SONET :

• No interoperable standard
• Tributary services require SONET mux services
• Low cost effective for low channel numbers.
• SONET/SDH network management system not well equipped to handle the DWDM method and management
• Bandwidth efficiency is a problem at higher capacity
• More overhead is required

Application of SONET

SONET has commonly transmitted data at speed between 155 megabits per second and 2.5 gigabits per second. To the build these high bandwidth data streams, the SONET multiplexer together channels having the bandwidth as low as 64-kilobits per second into data frames sent at fixed intervals. So now let us check out the application of SONET to know more details about SONET.

• SONET was originally designed for the public telephone network.
• SONET acts as a carrier of multiple higher-level application protocol.
• SONET provides a layer 1 or interfaces layer technology also termed physical layer in the OSI model.
• SONET is used to Multipoint configurations, enhanced performance, monitoring, and enhanced and integrated OAM.

What is SONET

Nowadays carrier synchronous digital hierarchy  (SDH) is an international standard for high-speed telecommunication networks. It is a synchronous system which provides simple network infrastructure and it is a more flexible network. SONET is very similar to SDH. SONET is the standard used in the US where SDH is the standard used outside the US also. Before we started the details about SONET/ SDH first we will discuss why using SONET/ SDH and also a full form of SONET.

• In SONET yield thinner cable than copper
• The lower bit error rate
• Higher bandwidth per fiber
• Higher transmission reliability 

SONET network is a transmission interface originally proposed by the broadband ISDN network. Now in this article, we talk about some important characteristics, similarities, major difference between SONET and SDH, SONET network topology. first, now let us check it out some important point SONET as well as SDH.

• SONET is a synchronous network while SDH is also synchronous network with an optical interface.
• SONET interface defines all layers, from the physical to the application layers, while SDH is a set of standard interfaces in a network of elements that conform to these interfaces.

SONET has commonly transmitted data at speed between 155 megabits per second and 2.5 gigabits per second. To the build these high bandwidth data streams, SONET  is multiplexer together channels having the bandwidth as low as around 64-kilobits per second into data frames sent at fixed intervals.

This article gives information about both SONET and SDH  are based on a structure that has a basic frame format and speed. All the base signaling level called STS-1, SONET support 51.84 Mbps and this STS-1 frame can be carried in an OC-1 signal. The SDH level and frame format used by the synchronous transport module(STM).

SONET versus SDH :

• Bitrate and frame format organization
• Frame synchronization schemes
• Error control
• Multiplexing and demultiplexing rules

SONET and SDH rates :

SONET Signal - STS-1, Optical carrier - OC-1

Data rate - 51.84 Mbps

Payload rate - 50.112 Mbps

SONET signal - STS-3,Optical carrier - OC-3,

SDH ITU-T - STM-1

Data rate - 155.52 Mbps

Payload rate - 150.336 Mbps

SONET Signal - STS-9, Optical carrier - OC-9,

SDH ITU-T - STM-3

Data rate - 466.56 Mbps

Payload rate - 451.008 Mbps

SONET signal - STS-12, optical carrier- OC-12
SDH ITU-T - STM-4
Data rate - 622.08 Mbps
Payload rate - 601.344 Mbps

STS-1 - Synchronous transport signal -1 

OC - Optical carrier

STM - Synchronous transport module

ITU-T - International telecommunication union telecommunication standardization sector.

Application of SONET :

• Used for the public telephone network.
• SONET acts as a carrier of multiple higher-level application protocol.
• SONET provides a layer 1 or interfaces layer technology also termed physical layer in the OSI model.
• Used to Multipoint configurations, enhanced performance, monitoring, and enhanced and integrated OAM.

You may also check it out :

Advantages and disadvantages of SONET

What is DWDM

Before we learn about the DWDM first let it check out the full form of DWDM. DWDM stands for dense wavelength division multiplexing. Hence the dense means the wavelength channel is very narrow and also very close to each other. 

Dense wavelength division multiplexing(DWDM) is technology put data from different sources together in an optical fiber, which uses single-mode fiber to carry multiple light waves of different frequencies.

For 100 GHz dense WDM, the interval between the adjacent channel is only 100 GHz, for example, the adjacent channels could be 1533.33 nm, 1533,12 nm, 1531.90 nm.

DWDM is widely used for the 1550 nm band so as to help the capabilities of EDFA full form. EDFA as are commonly used for the 1525 nm - 1565 nm.

Dense wavelength division multiplexing is an important innovation in optical network and provides many benefits of DWDM. It can be used various applications like  utilize the existing thin fiber and building or expanding a network

DWDM system structure :

DWDM system consists of transmitter, receiver, Multiplexer, optical amplifier (EDFA), demultiplexer. The figure shows a typical application of a DWDM system

Transmitter: Laser that transmits data with a very accurate wavelength each laser is configured to transmit in a certain wavelength.

Receiver: Component that receives the signal and transmits them into a de-multiplexer.

DWDM system

EDFA: Erbium-doped fiber amplifier. Optical repeater device that amplifies the optical signal, It is a silica-based optical fiber that doped with erbium that boosts the power of the wavelength.

Add and drop: Component that receives a fiber optic with some wavelength multiplexed, and can drop or add a certain lambda from the signal.

DWDM multiplexers: Receive many optical signals, each one is a different wavelength, and transmit the entire wavelength in one optic fiber.

DWDM de-multiplexer: Receive all the signal in one optic fiber, and transmit each wavelength in a different fiber.

DWDM applications:

• It can be used for signal transmission
• It is ready to make for long distance, Telecommunication operator that use either point to point or ring topology 
• Utilize the existing thin fiber
• Building or expanding network
• The transparency of the DWDM system to  various bit-rate and protocols
• Network wholesalers can lease capacity rather than entire fiber cable

What is WDM

In this method, the scheme of combining a number of wavelength over a single fiber called wavelength division multiplexing. In this techniques fiber optic transmission using multiple light wavelength to send the data over the same medium or device. In fiber optic, two or more wavelength (colors) of light can travel on one fiber and several signals can be transmitted in optical waveguide at differing wavelengths. 

So the combining a number of wavelengths over a single fiber called WDM full form is wavelength division multiplexing.

In WDM each input generated by a separate optical source with a unique wavelength. An optical multiplexer couples light from individual sources to the transmitting fiber shown in the figure. 

At the receiving station, an optical demultiplexer is required to separate the different carriers before photodetection of the individual signal.

WDM scheme

To prevent spurious signal to enter into receiving channel, the demultiplexer must have a narrow spectral operation with sharp wavelength cut-offs. The acceptable limit of cross talk is -30 dB. 

Features of WDM :

The following features of WDM are given below:

• Capacity upgrade for the system - Each wavelength support independent data rate in Gbps.
• Wavelength routing for the device - Link capacity and flexibility can be increased by using multiple wavelengths.
• Transparency of the system - WDM can carry fast asynchronous, slow synchronous, synchronous analog and digital data.
• Wavelength switching for the system - WDM can add or drop multiplexer, cross-connects and wavelength converters.

WDM has wide application in the communication system because of this useful feature details we show above. Other method called DWDM, it's different from WDM. The main difference between WDM and DWDM is DWDM has a greater overall capacity so DWDM spaces the wavelength more closely than WDM.

Application of WDM :

• SONET network
• Dense WDM allows to muxed and de-muxed numbers of channel closer to one another to achieve greater efficiency
• FDM to an optical fiber
• Optical transport network
• Local exchange network

WDM driver:

WDM driver is classified into three types :

• Bus driver
• Function driver
• Filter driver

Function driver :

• A function driver is a specific individual device, such as a printer.

Bus driver :

• Bus driver uses individual buses like PCI, SCSI, and USB, adapter or bridges. It is reported to the child device that is connected to the bus.

Filter driver :

•  It is I/O request for a device, which is a class of device or bus device.

Features of WDM

The technology of WDM full meaning is wavelength division multiplexing. This technology widely used in optical transport networks so many application of WDM in the communication system. The technical requirement is only that the laser is of very specific and that the DWDM full form is capable of distinguishing each wavelength without cross-talk. This article gives some features of WDM to give more information about WDM.

• Capacity upgrades - Since each wavelength support independent data rate in up to Gbps range.
• Transparency - WDM can carry fast asynchronous, slow synchronous, synchronous analog and also provide digital data.
• Wavelength routing - Link capacity and flexibility can be increased by using multiple wavelengths.
• Wavelength switching - WDM can add and drop multiplexers, cross-connect and wavelength converters.

Application of WDM

The technology of WDM is nothing but wavelength division multiplexing the full form of WDM. This technology widely used in optical transport networks. The technical requirement is only that the laser is of very specific and that the DWDM full form is capable of distinguishing each wavelength without cross-talk. This article gives some application of WDM to give more information about WDM.

• In SONET network
• Dense WDM multiplexing allow to muxed and demuxed numbers of channel closer to one another to achieve greater efficiency
• FDM to the optical fiber
• Optical transport network
• Local exchange network

You can also know the feature and applications of WDM.