Specifical description of WDM systems

Posted on by FS.COM

What’s WDM? It’s short for Division Multiplexing Wavelength technology. A WDM system uses a multiplexer at the transmitter to join the signals together, and a demultiplexer at the receiver to split them apart. It contains DWDM and CWDM.

DWDM is short for Dense Wavelength Division Multiplexing, an optical technology used to increase bandwidth over existing fiber optic backbones.DWDM transmission technique through optical fiber using the C band (1550 nm). That is a multiplexing method very similar to the frequency division multiplexing is used in electromagnetic transmission means. Several carrier signals (optical) are transmitted by a single optical fiber using different wavelengths of laser beam each. Each optical carrier is an optical channel that can be treated independently of other channels that share the medium (fiber optic) and contain different types of traffic. In this way can multiply the effective bandwidth of the optical fiber, so as to provide bidirectional communications. This is a very attractive transmission technique for telecom operators by allowing them to increase capacity without additional wiring or trenching. To transmit using DWDM is needed from complementary devices: a transmitter side muxer y demuxer at a receiver side it.

DWDM modules inlcude DWDM demux(mux) module and DWDM OADM module. As for DWDM demux(mux), the common configuration is 2CH, 4CH, 8CH, 16 CH, 32CH, 40CH channels. They are available in the form of Plastic ABS module cassette, 19″ rack mountable box or standard LGX box. And no matter what kind of connectors, like FC, ST, SC, LC etc, all are available on our website, and we also can mix connector on one device. A key advantage to DWDM is that it’s protocol- and bit-rate-independent. DWDM-based networks can transmit data in IP, ATM, SONET /SDH, and Ethernet, and handle bit rates between 100 Mb/s and 2.5 Gb/s. Therefore, DWDM-based networks can carry different types of traffic at different speeds over an optical channel.

CWDM is short for Coarse Wavelength Division Multiplexing. Originally, the term “coarse wavelength division multiplexing” was fairly generic, and meant a number of different things. In general, these things shared the fact that the choice of channel spacings and frequency stability was such that erbium doped fiber amplifiers could not be utilized. Prior to the relatively recent ITU standardization of the term, one common meaning for coarse WDM meant two (or possibly more) signals multiplexed onto a single fiber, where one signal was in the 1550 nm band, and the other in the 1310 nm band.

CWDM modules include CWDM mux/demux module and CWDM OADM module. The common configuration of CWDM mux/demux module is 2CH, 4CH, 8CH, 16CH, 18CH CWDM mux/demux module. 3 Single fiber or dual fiber connection for CWDM Mux/demux are available. Accordingly, they have two important characteristics inherent in systems employing CWDM optical components which allow easier and therefore also cheaper than in DWDM systems. CWDM is very simple in terms of network design, implementation, and operation. CWDM works with few parameters that need optimization by the user, while DWDM systems require complex calculations of balance of power per channel, which is further complicated when channels are added and removed or when it is used in DWDM networks ring, especially when systems incorporate optical amplifiers.

FS.COM FHD Fiber Enclosure
January 2017
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