Today’s services like voice, video and data networks are getting complex and growing tremendous, as well as requiring more bandwidth and faster transmission rates over farther distances. All these cause ferocious competition in the service provider market. And it’s impossible to charge more for the ever-increasing access speed, which resulted in the deployment of DWDM (dense wavelength-division multiplexing) technology in the long-haul transoceanic and terrestrial networks. As DWDM equipment becomes more economical and cost-effective, to deploy them in the metropolitan area network (MAN) is necessary.
Why DWDM is Necessary for MANs?
When it comes to DWDM for MANs, many people may ask “Why is DWDM suddenly so popular for MAN applications?” Considering both the DWDM technology and MAN, this question can be discussed from two aspects.
The first one is the situation of MAN at present. The practical demands for bandwidth and speed of users affect service providers in the MANs. They have to face problems such as service diversity, bandwidth scalability and fiber exhaustion. Bandwidth scalability deals with the capability of the fiber to carry traffic at exponentially greater speeds. Only by that, the bandwidth provided by service managers may meet the requirements. As for fiber exhaustion, adding more fiber cables may be helpful, but it will cost more and need a long time to finish.
Another one is the advantages of deployment DWDM technology. DWDM technology was first deployed on long-haul routes in a time of fiber scarcity. And it finds applications mainly in ultra-high bandwidth long haul as well as in ultra-high-speed metropolitan or inner-city networks, and at the edge of other networks like SONET, SDH and IP. As the ubiquitous deployment of DWDM network and the passive or active DWDM equipment, DWDM technology is expected to be the low-cost solution in MANs and many access-type networks like FTTH and FTTD.
Essential DWDM Equipment Used in MAN
As we know, in DWDM networks, multiple wavelengths of light are multiplexed into one single fiber. Therefore, DWDW equipment should be capable of combing or removing signals. Here are three main types of DWDM equipment used in MAN.
DWDM Multiplexer and Demultiplexer (DWDM Mux/Demux)
DWDM Mux/Demux modules deliver the benefits of DWDM technology in a fully passive solution. They provide a good solution for long-distance links where wavelengths are packed tightly together over the C-band range of wavelengths, up to 48 wavelengths in 100GHz grid (0.8nm) and 96 wavelengths in 50GHz grid (0.4nm). Usually the common configuration of DWDM Mux/Demux is from 8 channels to 96 channels.
DWDM Optical Add/Drop Multiplexer (DWDM OADM)
In order to connect different sites via individual wavelengths, a DWDM system needs to have the capability to add and drop services at distinct locations. That’s why DWDM OADM is needed. OADM can pass-through, remove or add the channels as required. It’s a pass type of DWDM equipment. And the optical losses are different for the add, drop, and pass-through channels.
DWDM Erbium-Doped Fiber Amplifier (DWDM EDFA)
Since DWDM network is designed for long runs transmission, the optical power of signals will attenuate with the distances increase. To ensure the quality of signals, DWDM EDFA are used according to the power budget between the transmitter and receiver. Usually based on the used places, there are three common types of fiber amplifiers: booster, in-line amplifier and pre-amplifier. And the gain also can be customized based on specific needs.
fiber-mart.COM DWDM Solution for Metropolitan Area Network
Today’s explosion in data traffic, fueled in large part by the growth of the Internet, has caused rapid depletion of available fiber bandwidth in the metropolitan area. The bandwidth bottleneck is now that of the MANs, where capacity has not increased as greatly as the long-haul networks. To meet the demand for long runs transmission in MANs, fiber-mart.COM provides FMT multi-service transport platform for flexible and high density DWDM networking solution. All DWDM equipment like EDFA, OEO, DCM and OLP (optical line protection) come in small plug-in cards, enabling easy installation and management during network deployment. For more details about this DWDM solution, please read this article: Extend DWDM Network Transmission Distance With Multi-Service Transport Platform