Tag: DWDM

CWDM/DWDM Integration

CWDM/DWDM Integration

DWDM-CWDM integration – an easy-to-realize expansion of existing CWDM systems

CWDM/DWDM

The difference between CWDM and DWDM lies in the channel spacing between neighbored wavelengths, for CWDM 20 nm and for DWDM 0.8/0.4 nm (using 100 GHz/50 GHz grid). Pan Dacom Direkt utilizes this advantage for an efficient CWDM/DWDM integration. Thereby up to sixteen DWDM channels are transmitted simultaneously in only one CWDM channel (1530 nm and 1550 nm). Thus an easy-to-realize channel extension can be achieved under continued use of existing CWDM components and thereby garantuees a protection of investment.

CWDM-DWDM integration – an easy-to-realize expansion of existing CWDM systems
CWDM-DWDM integration – an easy-to-realize expansion of existing CWDM systems

What is DWDM

DWDM (Dense Wavelength Division Multiplexing)

DWDM definition:

Up to 40/80 wavelength over one pair of fiber

DWDM highlights

DWDM
DWDM
  • Up to 90 DWDM wavelength over one pair of fiber
  • DWDM channel spacing 0.8 nm (100 GHz grid) or 0.4 nm (50 GHz grid)
  • Distances over 1,000 km can be achieved with the use of optical amplifier
  • DWDM wavelength: 1528 nm (channel 61) to 1563 nm (channel 17)

 

 

 

 

DWDM principle

The functionality of DWDM resembles to the one of CWDM. Unlike to CWDM technology, the channel spacing for DWDM is 0.8/0.4 nm (100 GHz/50 GHz grid). This small channel spacing allows to transmit simultaneously much more information.Currently a restriction on wavelengths between 1530 nm and 1625 nm exists which corresponds to the C and L band. In this connection DWDM wavelengths from DWDM technology is more expensive compared to CWDM caused by the need of more sophisticated transceivers.

DWDM
DWDM

 

What is WDM?

The IT refers to a medium where information is transmitted via a link. If two locations want to communicate with each other, one link is sufficient. To connect more locations more links are required What if only one link e.g. between two cities is available, but more applications shall be connected? Using the WDM technology, fiber optic links can be utilized for data transmission more efficiently.

WDM basics

The idea of xWDM technology

Each application is allocated to a dedicated color (wavelength) to communicate with a remote station. The advantage is that different colors can be simultaneously transmitted using one pair of fiber. For this purpose a multiplexer combines all different colors which will then be transmitted to the remote station over one pair of fiber. At the remote site the combined signal is separated again into different colors by a demultiplexer. Generally only one light beam with one wavelength is transferred over a pair of fiber. The wavelength multiplexing technology provides the ability to transmit more light beams, each having different wavelengths, using the same optical link. Due to the fact that wavelengths do not interfere, single light beams can be separated from each other using simple filters. A laser serves as the source of light and light-sensitive diode as receiver unit. Wavelength multiplexing is differentiated in CWDM (Coarse Wavelength Division Multiplexing) and DWDM (Dense Wavelength Division Multiplexing) technology. Advantage: With the use of WDM, it is possible today to transfer nearly 1 Tbps (C-band) via one pair of fiber.