DWDM vs CWDM the most effective method

Within today’s globe associated with rigorous conversation requirements as well as needs, “fiber optic cabling” has turned into a extremely popular expression. In neuro-scientific telecoms, information middle online connectivity as well as, movie transportation, dietary fiber optic wiring is actually extremely appealing with regard to today’s conversation requirements because of the huge bandwidth accessibility, in addition to dependability, minimum lack of information packets, reduced latency as well as elevated protection. Because the bodily dietary fiber optic wiring is actually costly in order to put into action for every person support, utilizing a Wavelength Department Multiplexing (WDM) with regard to growing the capability from the dietary fiber to transport several customer interfaces is really a extremely recommended. WDM is really a technologies which brings together a number of channels associated with data/storage/video or even tone of voice methods on a single bodily fiber-optic cable television by utilizing a number of wavelengths (frequencies) associated with gentle along with every rate of recurrence transporting another kind of information. By using optical amplifiers and also the improvement from the OTN (DWDM System) coating designed with FEC (Ahead Mistake Corection), the length from the dietary fiber optical conversation may achieve a large number of Kms with no need with regard to regeneration websites.

 

CWDM VS DWDM

DWDM (Dense Wavelength Division Multiplexing) is a technology allowing high throughput capacity over longer distances commonly ranging between 44-88 channels/wavelengths and transferring data rates from 100Mbps up to 100Gbps per wavelength. Each wavelength can transparently carry wide range of services such as FE/1/10/40/100GBE, OTU2/OTU3/OTU4, 1/2/4/8/10/16GB FC,STM1/4/16/64, OC3/OC12/OC48/OC-192, HD/SD-SDI and CPRI. The channel spacing of the DWDM solution is defined by the ITU.xxx (ask Omri) standard and can range from 25Ghz, 50GHz and 100GHz which is the most widely used today. Figure – 1 shows a DWDM spectral view of 88ch with 50GHz spacing.

 

DWDM systems can offer as much as ninety six wavelengths (from 50GHz) associated with combined support kinds, and may transportation in order to miles as much as 3000km through implementing amplifiers, because shown within determine two) as well as distribution compensators therefore growing the actual dietary fiber capability with a element associated with x100. Because of its much more exact as well as stable lasers, the actual DWDM technologies is commonly more costly in the sub-10G prices, however is really a appropriate answer and it is ruling with regard to 10G support prices as well as over supplying big capability information transportation as well as online connectivity more than lengthy miles from inexpensive expenses. The actual DWDM answer these days is usually inlayed along with ROADM (Reconfigurable Optical Add Drop Multiplexer) that allows the actual creating associated with versatile remotely handled national infrastructure by which any kind of wavelength could be additional or even fallen from any kind of website. A good example of DWDM gear is actually nicely shown through PL-1000, PL-1000GM, PL-1000GT, PL-1000RO, PL-2000 as well as PL-1000TN through DK Photonics Systems.

 

CWDM (Coarse Wavelength Division Multiplexing) proves to be the initial entry point for many organizations due to its lower cost. Each CWDM wavelength typically supports up to 2.5Gbps and can be expanded to 10Gbps support. This transfer rate is sufficient to support GbE, Fast Ethernet or 1/2/4/8/10G FC, STM-1/STM-4/STM-16 / OC3/OC12/OC48, as well as other protocols. The CWDM is limited to 16 wavelengths and is typically deployed at networks up to 80Km since optical amplifiers cannot be used due to the large spacing between channels. An example of this equipment is well demonstrated by PL-400, PL-1000E and PL-2000 by DK Photonics Networks.

 

You will need to remember that the complete selection regarding DK Photonics’ products was created to help equally DWDM and also CWDM engineering through the use of specifications centered pluggable optical web template modules for instance SFP, XFP and also SFP+. The particular engineering employed will be cautiously computed every venture and also in accordance with consumer specifications regarding length, ability, attenuation and also upcoming wants. DK Photonics furthermore gives migration way coming from CWDM to be able to DWDM permitting lower access expense and also upcoming enlargement which can be looked at inside the DWDM above CWDM engineering site.

Differences Between PLC Splitters and FBT Coupler

by Fiber-MART.COM

FBT Coupler and PLC splitter Tech

 

PLC Splitter

 

Planar Lightwave Circuit (PLC) splitter, PLC splitters are used to distribute or combine optical signals. It is based on planar lightwave circuit technology and provides a low cost light distribution solution with small form factor and high reliability. Planar lightwave circuit (PLC) splitter is a type of optical power management device that is fabricated using silica optical waveguide technology to distribute optical signals from Central Office (CO) to multiple premise locations.

 

FBT Coupler

 

Fused biconical taper,this is traditional technology to weld several fiber together from side of the fiber.

 

2. Comparison between FBT and PLC.

 

PLC splitter

 

SpliSplit Ratio (Max): 1*64 splits

Eveness: Can split light evenly

Size: Compact size

 

FBT coupler

 

Split Ratio: 1*8 splits

Eveness: Eveness is not very precise

Size: Big size for multi splits

 

TDL (Temperature Dependent loss)

 

Due to the manufacturing process and to the sensitivity of the fused region and of the splices integrated in the device, Fused coupler manufacturers have to specify also the TDL value. for a 1×2 Fused coupler, a typical value is +/10.15dB for a temperature range from -5 to +75 centigrade . At the first sight, it could look good, but we have here again to take into account the cascading effect. To make the comparison with 1×8 PLC splitter we have to multiply 0.15 by 3 (3 1×2 for each arm) to finally obtain 0.45dB.

 

PLC splitter works from -40 to 85 centigrade with a typical TDL of out +/- 0.25dB (-5 to 75 centigrade:+/-0.15dB)

 

Please note that this TDL effect is already included in the Max. insertion loss specifications available on data sheets.

 

PDL (Polarization dependent loss)

 

An lon-exchange PLC splitter shows a PDL much less than 0.2 dB independently from the split-ratio. A 1×2 fused coupler PDL ranges from 0.1 to 0.15dB.Also in this case, we have to cascade discrete 1*2 Fused coupler to obtain the desired split-ratio, Then also PDL will be increased.

 

A 1×8 fused coupler will show up to 0.45dB PDL, what is more than the double of a 1×8 PLC splitter.

 

Reliability

 

As previously explained, to fabricate  1×8 fused coupler, you need 7discrete 1×2 couplers and 6 splices. The risk of failure of a device, normally calculated by parameter called FIT(failure in time), is typically low for a single 1×2 fused coupler, but in the case of a 1×8 fuse fused coupler ,it has to be at lease multiplied by 7 and in addition to add the risk associated to the massive presence of splices in the circuits. As everybody knows, a splice is a potential failure point in a system to be minimized a s much as possible.At the contrary, a PLC splitter knows only 2 critical  points: input and output

 

People take advantage of fiber optic splitter that will send or simply combine optical signals in a good many products, which include FTTH solution, or anything else. Once in a while contain a challenge: Will certainly Make the most of PLC Splitter or FBT Coupler?

 

When you undertake compare, came across undertake compare meant for tools within the same exact split-ratio.

 

The figure 1 shows the insertion loss plot of a standard 1×8 PLC splitter from 1250 to 1650 nm. You can observe the maximum insertion loss including the water-peak in E band region(1360 to 1460 nm) and also the excellent uniformity out of this plot.

 

Typical value is 9.8dB for insertion loss and 0.5dB for uniformity.

 

A 1×2 fused coupler insertion loss plot is showed in the figure 2.if you analyze the operating wavelength range from 1250 to 1650 nm as for PLC splitter you will still find an overall good performance level. But that’s a single 1×2 fused coupler, so you are not comparing the same devices.

 

The 3rd plot represents the insertion loss spectral behavior for 1×8 fused coupler. To fabricate a 1×8 fused coupler device each arm have to be manufactured using 3 cascaded (spliced) 1×2 couplers. it means that the “worst” arm could show 10.8dB insertion loss max and the uniformity will be 3dB.

What is DWDM and Why is it Important?

It has been almost 20 years since DWDM came on the scene with Ciena’s introduction of a 16 channel system in March of 1996, and in the last two decades it has revolutionized the transmission of information over long distances.  DWDM is so ubiquitous that we often forget that there was a time when it did not exist and when accessing information from the other side of the globe was expensive and slow.  Now we think nothing of downloading a movie or placing an IP call across oceans and continents.  Current systems typically have 96 channels per optical fiber, each of which can run at 100Gbps, compared to the 2.5Gbps per channel in the initial systems.  All of this got me thinking about how it often takes two innovations coupled together to make a revolution.  Personal computers did not revolutionize office life until they were coupled with laser printers.  Similarly, the benefits of DWDM were enormous because of erbium doped fiber amplifiers (EDFAs).

DWDM stands for Dense Wavelength Division Multiplexing, which is a complex way of saying that, since photons do not interact with one another (at least not much) different signals on different wavelengths of light can be combined onto a single fiber, transmitted to the other end, separated and detected independently, thus increasing the carrying capacity of the fiber by the number of channels present.  In fact non-Dense, plain old WDM, had been in use for some time with 2, 3 or 4 channels in specialized circumstances.  There was nothing particularly difficult about building a basic DWDM system.  The technology initially used to combine and separate the wavelengths was thin film interference filters which had been developed to a high degree in the 19th Century.  (Now a ’days photonic integrated circuits called Arrayed Waveguide Gratings, or AWGs are used to perform this function.)  But until the advent of EDFAs there was not much benefit to be had from DWDM.

Fiber optic data transmission began in the 1970s with the discovery that certain glasses had very low optical loss in the near infrared spectral region, and that these glasses could be formed into fibers which would guide the light from one end to the other, keeping it confined and delivering it intact, although reduced by loss and dispersion.  With much development of fibers, lasers and detectors, systems were built which could transmit optical information for 80km before it was necessary to “regenerate” the signal.  Regeneration involved detecting the light, using an electronic digital circuit to reconstruct the information and then retransmitting it on another laser.  80km was much farther than the current “line of sight” microwave transmission systems could go, and fiber optic transmission was adopted on a wide scale.  Although 80 km was a significant improvement, it still meant a lot of regeneration circuits would be needed between LA and New York.  With one regeneration circuit needed per channel every 80 km, regeneration became the limiting factor in optical transmission and DWDM was not very practicable.  The then expensive filters would have to be used every 80 km to separate the light for each channel before regeneration and to recombine the channels after regeneration.

Since full regeneration was expensive, researchers began to look for other ways to extend the reach of an optical fiber transmission system.  In the late 1980s Erbuim Doped Fiber Amplifers (EDFAs) came on the scene.  EDFAs consisted of optical fiber doped with Erbium atoms which, when pumped with a laser of a different wavelength, created a gain medium which would amplify light in a band near the 1550nm wavelength.  EDFAs allowed amplification of the optical signals in fibers which could counter the effects of optical loss, but could not correct for the effects of dispersion and other impairments.  As a matter of fact, EDFAs generate amplified spontaneous emission (ASE) noise and could cause fiber nonlinearity distortions over a long transmission distance.  So EDFAs did not eliminate the need for regeneration completely, but allowed the signals to go many 80 km hops before regeneration was needed.  Since EDFAs were cheaper than full regeneration, systems were quickly designed which used 1550nm lasers instead of the then prevailing 1300nm.

Then came the “ah ha” moment.  Since EDFAs just replicated the photons coming in and sent out more photons of the same wavelength, two or more channels could be amplified in the same EDFA without crosstalk.  With DWDM one EDFA could amplify all of the channels in a fiber at once, provided they fit within the region of EDFA gain.  DWDM then allowed the multiple use of not only the fiber but also the amplifiers.  Instead of one regeneration circuit for every channel, there was now one EDFA for each fiber.  A single fiber and a chain of one amplifier every 40~100 km could support 96 different data streams. Regenerators are still needed today, every 1,200~3,500km, when the accumulated EDFA ASE noise exceeds a threshold that a digital signal processor and error correction codec can handle.

Of course, since the gain region of the EDFA was limited to about 40 nm of spectra width, great emphasis was placed on fitting the different optical wavelengths as close together as possible.  Current systems place channels 50GHz, or approximately 0.4 nm, apart, and hero experiments have done much more.

In parallel, new technologies have increased the bandwidth per channel to 100 Gbps using coherent techniques that we have discussed in other blog posts.  So a single fiber that in the early 1990s would have carried 2.5Gbps of information, now can carry almost 10 Terabits/sec of information, and we can watch movies from the other side of the globe.

SFP Optical Transceiver Modules

SFP package – hot little package module, the highest rate of up to 10G, is mostly used with LC interfaces. SFP is abbreviation of Small Form Pluggable, which can be simply considered as an upgraded version of GBIC. SFP module has half volume of GBIC, only the size of a thumb. It can be configured on the same panel, more than double the number of ports. SFP module has the same other basic functions as GBIC. Some switch vendors said the SFP module is mini GBIC.

SFP modules through the CDR and electronic dispersion compensation on the outside of the module, while the more reduced the size and power consumption. They are used for telecommunications and data communications applications in optical communication. SFP connected network devices such as switches, routers and other equipment motherboards and optical fiber or UTP cables. SFP is also a kind of industry specifications which some fiber optic device providers support. SFP modules support SONET, Gigabit Ethernet, Fiber Channel as well as some other communication standards. This standard extends to SFP+, which can support 10.0 Gbit/s transfer rate, including 8 gigabit Fiber Channel and 10GbE. The introduction of fiber optic and copper versions of the SFP+ module versions, and the module’s XENPAK, X2 or XFP version comparison, SFP+ module will remain in the part of the circuit board to achieve, rather than the module implementation.

SFP transceivers have many different types of transmission and reception, the user can select the appropriate link for each transceiver to provide based on available fiber types (such as multi-mode fiber or single-mode fiber) can reach the optical performance. Available optical SFP modules are generally divided into the following categories: 850nm / 550m distance MMF (SX), 1310nm wavelength / 10 kilometers from the SMF (LX), 1550nm / 40 km distance XD, 80 miles from the ZX, 120 yards from the EX or EZX, and DWDM. SFP transceivers are also available copper interfaces, making the design primarily for fiber optic communication devices are also able to host UTP network cable communication. There are also CWDM SFP and single-fiber “two-way” SFP.

SFP optical module configuration are: lasers (including transmitter TOSA with the receiver ROSA) and board composition IC and external accessories and external accessories, there are housing, base, PCBA, pull ring, clasps, unlock, rubber stopper composition, In order to facilitate the identification generally pull ring color discrimination module parameter type.

In accordance with the rate divided 155M/622M/1.25G/2.125G/4.25G/8G/10G, 155M and 1.25G market is used more, 10G technology is maturing, demand is rising attitude to development. In accordance with the wavelength divided 850nm/1310nm/1550nm/1490nm/1530nm/1610nm, the SFP 850nm wavelength multimode transmission distance 2KM below 1310/1550nm wavelengths for single mode, the transmission distance 2KM above, relatively speaking, this three wavelengths price is cheaper than the other three.

Many people do not know the difference between SFP and SFP+. This sometimes caused unnecessary trouble. 10G module has gone from 300Pin, XENPAK, X2, XFP development, and ultimately with the same size and SFP 10G transmission signal, which is the SFP+. SFP with its compact low cost advantages to meet the equipment needs of high-density optical modules, implemented from 2002 standard to 2010 has replaced 10G XFP and become the mainstream of market.

SFP+ optical modules have these following advantages. First, SFP+ package has the more compact dimensions than than XFP X2 (with the same size as SFP). Second, SFP+ optical modules can be direct connected with XFP, X2 and XENPAK modules which have the same types. Third, the cost ratio is lower than XFP, X2 and XENPAK products.

fiber-mart.com offers cost-effective standards-based compatible Cisco SFP Transceivers. As a 3rd party OEM manufacturer, our Cisco SFP transceiver is delivered to worldwide from our factory directly.

 

Enhance Network Capacity With CWDM Mux/Demux

by Fiber-MART.COM

Advanced networking technologies bring more convenience and flexibility to our lives, as well as the never-ending demand for higher bandwidth and faster transmission rates. To meet these requirements, service providers and network managers are more inclined to seek help from fiber optics. However, as available fiber infrastructure is restricted and to add more fiber is no longer a feasible and economical option, it is hence vital to search for more cost-effective methods to enhance network capacity. Wavelength-divison multiplexing (WDM) is a technology which multiplexes multiple optical signals onto a single fiber by using different wavelengths or colors of light. This technology can greatly reduce the cost of increasing network capacity without having to move a single shovelful of dirt or hang a single new fiber. This article mainly talks about CWDM.

CWDM Mux/Demux Overview

There are two types of WDM implementations: dense wavelength division multiplexing (DWDM) and coarse wavelength division multiplexing (CWDM). In the following part, we will introduce CWDM Mux/Demux solutions for promoting network capacity.

 

CWDM Mux/Demux, short for coarse wavelength division multiplexing multiplexer/demultiplexer, has proved to be a flexible and economical solution which allows for expanding the existing fiber capacity effectively. It enables operators to make full use of available fiber bandwidth in local loop and enterprise architectures. It can enhance capacity and increase bandwidth to the maximum over a single or dual fiber cable. Hence, by adopting CWDM Mux/Demux to the networking system, you are able to get other independent data links with less fiber cables required. CWDM Mux/Demux modules are wide from 2 channels to 18 channels in the form of 1RU 19’’ rack chassis.

 

 

The CWDM Mux/Demux has a long transmission distance coverage of multiple signals on a single fiber strand. It can support various types of signals such as 3Gbps/HD/SD, AES, DVB-ASI, Ethernet, etc. Furthermore, its ambient operating temperature is from -40℃ to 85℃, which means it is also suitable for outside plant applications. Besides, it requires no powering because of the thermally stable passive optics.

 

The Functions of CWDM Mux/Demux

Mux/Demux functions to multiplex or demultiplex multiple wavelengths, which are used on a single fiber link. The difference lies in the wavelengths, which are used. In CWDM space, the 1310-band and the 1550-band are divided into smaller bands, each only 20nm wide. In the multiplex operation, the multiple wavelength bands are combined (muxed) onto a single fiber. In a demultiplex operation, the multiple wavelength bands are separated (demuxed) from a single fiber.

 

In a hybrid configuration (mux/demux), multiple transmit and receive signals can be combined onto a single fiber. Each signal is assigned a different wavelength. At each end, transmit signals are muxed, while receive signals are demuxed. For example, in a simple full-duplex link, the transmit is assigned the 1530nm wavelength, while the receive signal is assigned the 1550nm wavelength.

 

CWDM Mux/Demux Product Solution

A CWDM Mux/Demux with up to 18 channels has been introduced to cater for the ever-increasing demand for massive bandwidth and higher capacity. Just as the name indicates, the 18-channel version can combine up to 18 different wavelength signals from different optical fibers into a single optical fiber, or separates up to 18 different wavelength signals coming from a single optical fiber. FIBER-MART.COM provides 18-CHCWDM Mux/Demux that is equipped with a monitor port, which is designed to ensure better CWDM network management.

 

This 18-CH CWDM Mux/Demux modules can multiplex and de-multiplex up to 18 CWDM sources over a single fiber with insertion loss below 4.9dB. It features a monitor port which ensures easy troubleshooting without downtime. Which efficiently contribute to expand the bandwidth of optical communication networks with lower loss and greater distance capacities.

 

Conclusion

In conclusion, CWDM Mux/Demux technology is a very effective method for overcoming fiber exhaust. Employing it in your fiber optic network can greatly increase bandwidth without the need to spend capital on new fiber construction projects. It is hence natural that the technology is considered as a feasible and economical solution to realize network capacity promotion. With this technology, fiber count is no longer a constraint to most service providers and enterprises.