According to the market demand for large transmission capacity in current optical interconnect,network managers are relying more on fiber optics, and requiring more bandwidth and faster transmission rates over ever increasing distances.
What is WDM?
Wavelength Division Multiplexing, WDM, is a technology that increases bandwidth by allowing different data streams at different frequencies to be sent over a single optical fiber network. Signals at WDM wavelengths are independent from each other.
Wave Division Multiplexing (WDM) technologies can increase capacity on the existing fiber infrastructure. WDM is a technology which multiplexes multiple optical signals onto a single fiber by using different wavelengths, or colors, of light. By utilizing WDM communication methods, network managers can realize a multiplicative effect in their available fiber’s capacity.
WDM technology— Short for wavelength division multiplexing, WDM is a way of transmitting multiple simultaneous data streams over the same fiber. Since this happens simultaneously, WDM does not impact transmission speed, latency or bandwidth. WDM functions as multiplexing multiple optical signals on a single fiber by using different wavelengths, or colors, of laser light to carry different signals. Network managers can thus realize a multiplication effect in their available fiber’s capacity with WDM.
Coarse Wave Division Multiplexing (CWDM)
CWDM increases fiber capacity in either 4, 8, or 18 channel increments. It is a method to maximize existing fiber by decreasing the channel spacing between wavelengths. Since CWDM is a passive technology, Another benefit to the passive CWDM technology is that no configuration is necessary, which makes CWDM a low-cost and effortless technology to implement. The most complex step in CWDM integration is aligning and connecting the patch cables from the correct wavelength optic to the correct port on the multiplexers on each end of the link.
The benefits of CWDM include:
- Passive equipment that uses no electrical power
- Extended Temperature Range (0˚C – 70˚C)
- Lower cost per channel than DWDM
- Scalability to grow fiber capacity with little or no increased cost
- Protocol transparent
- Simple to install and use
Drawbacks of CWDM:
- 18 channels may not be enough, and fiber amplifier cannot be used with them
- Passive equipment that has no management capabilities
- Not the ideal choice for long-haul networks
Dense Wave Division Multiplexing (DWDM)
Dense wavelength division multiplexing (DWDM) is a technology that puts data from different sources together on an optical fiber, with each signal carried at the same time on its own separate light wavelength. Using DWDM, is a layer-1 transport technology that multiplexes several optical signals into the same fiber by using different wavelengths (colors). It allows you to transport more data across existing dark fiber infrastructure.up to 80 (and theoretically more) separate wavelengths or channels of data can be multiplexed into a light-stream transmitted on a single optical fiber.
Benefits of DWDM:
- Transparency: due to that DWDM is with a physical layer architecture, it can transparently support both TDM and data formats such as ATM, Gigabit Ethernet, ESCON, and Fibre Channel with open interfaces over a common physical layer.
- Scalability: DWDM can leverage the abundance of dark fiber in many metropolitan area and enterprise networks to quickly meet demand for capacity on point-to-point links and on spans of existing SONET/SDH rings.
- Dynamic provisioning: fast, simple, and dynamic provisioning of network connections give providers the ability to provide high-bandwidth services in days rather than months.
Drawbacks of DWDM:
- DWDM solutions are quite expensive
- Active DWDM solutions require a lot of set-up and maintenance expense
CWDM Mux / Demux
Using CWDM multiplexing technology paired with wavelength specific optics in Transition Networks’ fiber optic devices and switching products allows you to realize the full benefit of CWDM technology. The modular approach that Transition Networks takes toward CWDM deployments makes scaling a project to fit your exact needs easy and affordable. Transition Networks also offers products that optimize standard fixed optic wavelengths on existing products by converting them to the appropriate CWDM “color” or wavelength.
DWDM Mux / Demux
the common configuration of DWDM Mux/Demux is from 8 to 96 channels. Maybe in future channels can reach 200 channels or more. DWDM system typically transports channels (wavelengths) in what is known as the conventional band or C band spectrum, with all channels in the 1550nm region. The denser channel spacing requires tighter control of the wavelengths and therefore cooled DWDM optical transceiver modules required, as contrary to CWDM which has broader channel spacing un-cooled optics, such as CWDM SFP, CWDM XFP.
To sum it up, With DWDM Mux/DeMux, single fibers have been able to transmit data at speeds up to 400Gb/s. there is no doubt that DWDM technology will reshape the future communication network by virtue of its various advantages and applications in many aspects.To expand the bandwidth of your optical communication networks with lower loss and greater distance capabilities.
WDM solution capacity expansion in a more cost-effective, simplified and flexible way.Fiber-MART can help you to choose the right WDM solution.Any question pls feel free to contact us .E-mail: Service@fiber-mart.com
In the communications market, Wavelength Division Multiplexing (WDM) is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths (i.e., colors) of laser light. This technique enables bidirectional communications over one strand of fiber, as well as multiplication of capacity.
Dense Wavelength Division Multiplexing (CWDM) networks need multiplexer/demultiplexer (MUX/DEMUX) modules to combine and split wavelength channels at standard ITU grid. These modules are generally called CWDM MUX/DEMUX.
The CWDM Mux/Demux is a universal device capable of combining nine optical signals into a fiber pair. It is designed to support a broad range of architectures, ranging from scalable point-to-point links to two fiber-protected rings. The market-standard LGX™ packaging of the CWDM Mux/Demux enables easy deployment in existing LGX-compatible frames or WaveReady 3500F shelves.
The CWDM Mux/Demux is designed to interoperate with both the WaveReady line of transponder and optical regenerator solutions as well as CWDM transponders and small form-factor pluggables (SFPs) used in widely available transmission equipment. With billions of field operating hours, the industry leading Lumentum optical multiplexing technology offers unparalleled reliability and leading-edge performance.
CWDM Mux/Demux is a flexible network solution for WDM optical networks. At most 18 full-duplex wavelengths can be added over a single fiber trunk which greatly alleviates fiber exhaustion. With low insertion loss and high stability, CWDM Mux/Demux is applied to many operations, such as CATV links, WDM systems, test and measurement, metro and access networks, FTTH networks, etc. The deployment of CWDM Mux/Demux is transparent and clear. Its compact form factor enables a much easier manipulation. Only coarse wavelengths can be transmitted over the fiber which reduces the WDM system cost.
Three kinds of CWDM Mux/Demux are widely used in the application. They are 1RU 19″ rack chassis CWDM Mux/Demux, half 19″/1RU CWDM Mux/Demux and splice/pigtailed CWDM Mux/Demux. CWDM Mux/Demux in 19 inch rack mount package is often used for CWDM, EPON and CATV network. Half 19″/1RU CWDM Mux/Demux is packed in LGX box using thing film coating and non-flux metal bonding micro optics packaging. Splice/pigtailed CWDM Mux/Demux is packed in the ABS box package based on standard thin film filter (TFF) technology.
Dense Wavelength Division Multiplexing (DWDM) networks need multiplexer/demultiplexer (MUX/DEMUX) modules to combine and split wavelength channels at standard ITU grid. These modules are generally called DWDM MUX/DEMUX.
DWDM Mux/Demux conveys optical signals in a more dense wavelength. It is especially used for long distance transmission where wavelengths are highly-packed together. The maximum delivered wavelengths can reach up to 48 channels in 100GHz grid (0.8nm) and 96 channels in 50GHz grid (0.4nm). DWDM Mux/Demux uses a reliable passive WDM technology that achieves low insertion loss. And it provides a solution for adding WDM technology to any existing network device. Applications like point-to-point DWDM fiber optimization, linear add/drop DWDM fiber optimization, external optical monitoring are typically using DWDM Mux/Demux module.
The functionality of DWDM (Dense Wavelength Division Multiplexing) resembles to the one of CWDM. The DWDM channel spacing is 0.8/0.4 nm (100 GHz/50 GHz grid). This small channel spacing allows to transmit simultaneously more information. Currently a restriction on wavelengths between 1530 nm and 1625 nm exists which corresponds to the C and L band. DWDM wavelengths are more expensive compared to CWDM caused by the need of more sophisticated transceivers.
Likewise, 1RU 19″ rack chassis DWDM Mux/Demux, Half 19″/1RU DWDM Mux/Demux and splice/pigtailed DWDM Mux/Demux are three divisions of DWDM Mux/Demux modules. The first type is in 19 inch rack mount package used for long-haul transmission over C-band range of wavelengths. The second one is in LGX package used for PDH, SDH/SONET, Ethernet services transmission. The last one is in ABS box package and its pigtails are labeled with wavelengths.
Comparison Between CWDM and DWDM System
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). this advantage for an efficient CWDM/DWDMintegration. 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.
Price difference—CWDM system carries less data, but the cabling used to run is less expensive and less complex. A DWDM system has much denser cabling and can carry a significantly larger amount of data, but it can be cost prohibitive, especially where there is a need for a large amount of cabling in an application.
Transmission distance—DWDM system is designed for longer distance transmission as stated above. They can transmit more data over a significantly larger run of cable with less interference than a comparable CWDM system. If there is a need for transmitting the data over a long range, DWDM system will likely be the best in terms of functionality of the data transmittal and the lessened interference over the longer distances that the wavelengths must travel.
CWDM system cannot transmit over long distances because the wavelengths are not amplified, and therefore CWDM is limited in its functionality over longer distances. Typically, CWDM can travel anywhere up to about 100 miles (160 km), while an amplified DWDM system can go much further as the signal strength is boosted periodically throughout the run. As a result of the additional cost required to provide signal amplification, the CWDM solution is best for short runs that do not have mission critical data.
To sum up, before buying We should first understand the differences between them,Fiber-Mart provides a series of CWDM DWDM MUX/DEMUX modules with as more as 18 channels (20nm spaced) in simplex or duplex configurations. All the CWDM DWDM modules are available with three types of packaging: ABS Pigtailed Box, Rack Chassis and LGX Cassette. For more details, please visit www.fiber-mart.com. Please not hesitate to contact us for any question. E-mail: email@example.com