Technology of DWDM Multiplexer and DWDM SFP+
Dense Wavelength Division Multiplexing is a special type of technology, which combines data that come from different sources, into one optical fiber. Every signal is carried on a different wavelength simultaneously. It is calculated that a DWDM technology can multiplex about 80 different channels or wavelengths on one optical fiber, which are transmitted in a light stream. Every channel holds a TDM, time division multiplexed signal. For instance, if there is a system that has channels that are capable of carrying 2.5Gbps, it will mean that a maximum of 200 billion bits will be delivered in a second by that optical fiber. In some situation, the DWDM is called the WDM, Wave Division Multiplexing.
Every channel in the system is demultiplexed into the main source at the end of every transmission, for that, it means that there can be different data formats, which can be transmitted at varied rates simultaneously. This implies that SONET, Synchronous Optical Network data, ATM, Asynchronous Transfer Mode and IP, Internet data, will be transferred simultaneously on the same optical fiber. The main aim of the DWDM multiplexer is to fix the issues of fiber exhaustion. Many organizations are opting for this type of technology.
The DWDM System
The general DWDM system is comprised of some major components, such as the following;
1. A Terminal multiplexer. The DWDM terminal multiplexer has a transponder, which will convert the wavelength for every data signal, along with an optical multiplexer. In some situation, they can have an EDFA, optical amplifier. Every transponder that receives any optical data signal, like SONET, will convert that signal into an electrical domain, then transmit it again with a 1,550nm band laser at a particular wavelength.
2. Intermediate line repeater. This one will be placed after about each 80 to 100km and it is used to substitute the optical power loss as the signal is traveling via the fiber. With this product, the multi-wavelength optical signal will be amplified using an optical amplifier.
3. Optical add-drop multiplexer or intermediate optical terminal. This is an amplification site, which is remotely located and it is used to amplify the multi-wavelength signals, prior to reaching the remote site.
4. A terminal demultiplexer. There is also the DWDM terminal demultiplexer, which has an optical de-multiplexer and transponders for converting the wavelengths. There can be one or more transponders, which helps to split the multi-wavelength optical signal into several data signals. They are then outputted on different fibers for the systems like SONET/SDH.
5. Optical Supervisory Channel, OSC. The OSC is a data channel that employs extra wavelength, mostly outside the optical amplifier amplification band. It will use wavelengths of 1510nm, 1620nm or 1310nm.
These are the major components and products of the DWDM system and they are the ones that promote the full functionality of the system.
Another common product that is used in this system is the DWDM transceiver, 10G DWDM SFP+ transceiver. This is a this is a device that will combine the function of a transmitter and a receiver. It is generally a device, which will convert the electrical signal to an optical signal and from it as well. It transmits and receives signals.