Metropolitan Area Network Access Layer CWDM Multiplexer Technology

Due to the rapid development of data services, network convergence speed accelerated MAN is becoming a hotspot of network construction, and more sensitive to the pressure of market competition makes the cost of telecom operators on the network (including construction costs and operation and maintenance costs). MAN for this market demand, low-cost CWDM products have emerged. MAN, short transmission distance, do not have to use the amplifier, optical fiber transmission attenuation value is less sensitive cwdm multiplexer technology can reduce the performance requirements of the device, components, thus greatly reducing the cost.

The spacing between the transmission of different wavelengths in the same fiber is the main parameter to distinguish between DWDM and CWDM. Usually the wavelength interval of the DWDM system 200GHz (1.6nm), 100GHz (0.8nm) or 50GHz (0.4nm), future systems may have a more narrow pitch. DWDM system, DFB (distributed feedback) laser as the light source, the temperature drift of the latter coefficient of 0.08nm / °C, it needs to use a cooling technique to stabilize the wavelength, in order to prevent changes in wavelength due to temperature drift to the multiplexer demultiplexing a filter passband.

CWDM (Coarse Wavelength Division Multiplexing) systems, coarse wavelength division multiplexing system, is a low-cost WDM transmission technology for MAN access layer. Principle, CWDM is the use of the optical multiplexer to different wavelengths of light signals multiplexed to a single optical fiber for transmission, at the receiving end of the link, with the optical demultiplexer fiber mixed signal is decomposed into different wavelengths signal, connected to the respective receiving apparatus. The main difference is that with the DWDM: 0.2nm to 1.2nm wavelength interval with respect to the DWDM system is concerned, CWDM has a wider wavelength interval, the industry accepted standards wavelength intervals of 20 nm.

CWDM technology full use of the characteristics of a short transmission distance of the MAN, without by EDFA amplification band limited, but may be on the entire optical fiber transmission window in the 1310-1560 nm wavelength interval much wider than DWDM system wave stars multiplexing. Due to the wide wavelength interval, the transmission distance is short, CWDM without selecting the expensive high wavelength stability and a high dispersion tolerance of the laser, which can greatly reduce the laser cost. In addition, CWDM without selecting costly dense wavelength division demultiplexer and multiplexer, simply choose the cheap coarse wavelength division multiplexer and demultiplexer; without complex control technology to maintain high system requirements; Simply using much cheaper than the multichannel laser without using EDFA, send / receive as a relay. Reduce device cost and system requirements, CWDM system cost than DWDM systems have dropped significantly.

Although the price is much lower cost than DWDM, CWDM systems and DWDM interface to support multi-service SDH interface, for example, can provide IP / Ethernet over SDH, ATM, over SDH; provide direct fiber connection port for the routers and ATM switches, IP / Ethernet over Optical and ATM over Optical. CWDM system can also use OUT (optical transmission unit) and OADM (optical add / drop multiplexing) with the use of standard wavelength DWDM system interconnect ring or access DWDM backbone layer. CWDM 1310nm SDH system compatibility has been widely used in MAN, the current DWDM can not do this. The CWDM technology also has the potential applied to the long-distance transmission capacity, broadband LAMAN (Raman) optical amplifiers into the commercial the CWDM technology there is likely to enter the long-distance transmission market.

CWDM by larger wavelength interval so that the optical transceiver modules and passive optical multiplexer / demultiplexer, cost reduction, and business transparency, simple operation and maintenance, scalability advantages, so by the industry attention, but CWDM cost advantage is not outstanding, the equipment is not perfect, the small number of optical channels. With the expansion of the market and technology development, located in the metropolitan area network access layer CWDM technology can have a good prospect of application.

Fiberstore is a fiber optic supplier with a variety of fiber optic products in stock ready to ship to you.For example,buy some CWDM ,you maybe need the CWDM OADM module,it is designed to optically add/drop one or multiple CWDM channels into one or two fibers.Whether your network has 1 or 2 cores of fiber, redundant network, ring or linear network design etc, we can offer various OADM configurations to tailor fit your network architect. Please contact us for more details.