#8 channels DWDM MUX/DEMUX

[qing-chloe-blog]

How to Realize 16 Channels Transmission in DWDM Network?

DWDM MUX/DEMUX plays a critical in WDM network building. 16 channels transmission is very common in DWDM networks. How to realize it in a simple way? This article intends to introduce two solutions to achieve 16 channels with different types of components. Which one is more cost-effective and competitive? The comparison between the them also will be explored. Hope it will help you when choosing fiber mux for your DWDM networks.

Solutions to Achieve 16 Channels Transmission in DWDM Network

In order to illustrate the solution more clearly, I take two types of DWDM MUX/DEMUX as an example. One is the traditional 16 channels dual fiber DWDM MUX/DEMUX. Another is two FMU 8 channels dual fiber DWDM MUX/DEMUX. The latter has an expansion port.

Solution One: Using Traditional 16 Channels DWDM MUX/DEMUX

The 16 channel DWDM MUX/DEMUX is a passive optical multiplexer designed for metro access applications. It’s built fiber mux and demux in one unit and can multiplex 16 channels on a fiber pair. In addition, this type of fiber mux also can be added some functional ports like expansion port, monitor port and 1310nm port, which make it possible to increase network capacity easily. The following is a simple graph showing the 16 channels transmission with this traditional DWDM MUX/DEMUX.

Solution Two: Using Two FMU 8 Channels DWDM MUX/DEMUX Modules

The FMU 8 channels DWDM MUX/DEMUX provide 8 bidirectional channels on a dual strand of fiber. Usually they are used together. Unlike the 16 channels DWDM MUX/DEMUX, this FMU 8 channels one has a more compact size, for it only occupies half space in a 1U rack. Put two FMU 8 channels DWDM MUX/DEMUX modules into one 1U two-slot rack mount chassis. two 8 channels DWDM MUX/DEMUX with different wavelengths are connected through the expansion port to realize 16 channels transmission in a DWDM network. Here is a graph showing how to achieve 16 channels DWDM transmission with these two 8m channels fiber muxes. As shown in the figure, two 8 channels DWDM MUX/DEMUX with different wavelengths are connected through the expansion port to realize 16 channels transmission in a DWDM network.

16CH DWDM MUX and Two FMU 8CH DWDM MUX: What’s the Difference When Deployed?

From the content above, we can see both solutions can realize the 16 channels transmission in a DWDM network. Then, are there differences between them? Or which is more competitive? Here is a simple analysis of the two solutions.

Firstly, comparing the two graphs above, the FMU 8 channels DWDM MUX/DEMUX are connected together by an expansion port, that’s why it can deliver 16 channels services like the traditional one. Except for connecting 8 channels DWDM MUX/DEMUX, the FMU fiber mux with expansion port also can be combined with other channels fiber mux like 2 channels, 4 channels or other channels, which offer more flexibility for optical network deployment and upgrade. And you can add DWDM into CWDM networks at some specific wavelengths with FS.COM FMU fiber mux.

Secondly, DWDM MUX/DEMUX price is always an important point that many network operators pay attention to. Therefore, when buying a fiber mux, the cost is a critical point to consider. If you search on Google, you will find the lowest price is $1100 in FS.COM. And the cost of using two 8 channels MUX/DEMUX is the same as the deployment of one 16 channels MUX/DEMUX. However, compared with the 16 channels DWDM MUX/DEMUX, the FMU 8 channels fiber mux provides a competitive solution for small networks which needn’t to buy a full-channel fiber mux that supports all 16 channels or more channels.

Conclusion

From the comparison above, the FMU 8 channels DWDM MUX/DEMUX is more flexible and cost-effective when deployed in WDM networks. How to choose is based on the requirements of your networks. FS.COM supplies two different types of these WDM MUX/DEMUX. Here is a simple datasheet of them. If you have more requirements for additional wavelengths, welcome to visit www.fs.com for more detailed information.

 Sources:http://www.fiber-optic-tutorial.com/16-channels-dwdm-mux-demux-in-dwdm-network.html

[optical-sintai]

DWDM Mux Demux

https://www.optical-sintai.com/products/dwdm-mux-demux/

01- 4CH DWDM Mux Demux

DWDM Mux Demux is usually used for long-haul transmission where wavelengths are packed tightly together over the C-band, up to 48 wavelengths in 100GHz grid(0.8nm) and 96 wavelengths in 50GHz grid(0.4nm).

 02- 8CH DWDM Mux Demux

The 8-Channel DWDM MUX-DEMUX module provides multiplexing and demultiplexing for up to 8 DWDM wavelengths in a single-wide module. All wavelengths fall within the pass-band of a C band channel, allowing the module to be used in DWDM applications to increase the number of wavelength circuits.

 03- 16CH DWDM Mux Demux

16 Channels Double Fiber Passive 100 GHz DWDM Mux/Demux is a member of the sentai Optics DWDM Series product line. We designed Sintai Optics DWDM Series products to allow easy, gradual, logical, and cost-efficient expansion of network bandwidth using industry-leading passive WDM technology.

 04- 18CH DWDM Mux Demux

The DWDM multiplexer/demultiplexer launched by Guangzhou Sintai Communication Co., Ltd. is designed for multi-wavelength DWDM network applications. It works on an ITU grid with 100 GHz channel spacing based on thin-film filter (TFF) technology.

[katherinewangfs-blog]

Can the Hybrid CWDM-DWDM System Work for Higher Capacity?

When facing the capacity-hungry issue, have you ever hesitated over which WDM system should be choose? As the CWDM system is a more economical solution for limited expanding capacity while the expensive DWDM solution enables much higher capacity, which one should be chose is really a tough decision. In order to solve the issue, can we deploy a Hybrid CWDM-DWDM system, for not choosing a wrong solution to increase the network capacity? Thereby, both the bandwidth shortage with CWDM solution or the potential bankruptcy with DWDM solution can be avoided. Let’s seeking the answer.

Can the Hybrid CWDM-DWDM System Work?

Can the Hybrid CWDM-DWDM system work for higher network capacity? The answer is yes. In fact, it is an ideal solution for boosting the network capacity, which is designed with merging DWDM and CWDM traffic seamlessly at the optical layer, taking full use of the WDM technology. In a hybrid CWDM-DWDM system, more channels can be added to deal with the limited capacity and reach in a CWDM system. That’s to say, the hybrid CWDM-DWDM system utilizes the DWDM technology to empower CWDM system, by integrating CWDM and DWDM equipment, which offers true pay-as-you-grow capacity growth and investment protection.

In short, the hybrid CWDM-DWDM system is a simple, plug-and-play option that enables more DWDM channels interleaved with the existing CWDM channels, for transmitting more data signals. It gets the utmost out of CWDM and DWDM technologies in a single system that greatly reduces the cost, simplifies the installation and keeps the system flexibility for bigger network capacity.

How to Build a Hybrid CWDM-DWDM System?

In general, a normal complete optical connection can be simply done by using a length of fiber patch cable to connect two fiber transceivers and then separately inserting the two transceivers into the ports of two switches. While in a hybrid CWDM-DWDM system, both the CWDM Mux Demux and DWDM Mux Demux should be added offering multiple channels to multiplex and demultiplex the signals. Here offers a typical 44 channel hybrid CWDM-DWDM system information for your reference.

From the figure, we can learn that the original CWDM system uses two 8 channel CWDM Mux Demux with wavelengths from 1470 nm to 1610 nm (20nm channel spacing). In order to add more channels for transmitting larger data signals, two pairs of DWDM multi-channel Mux/Demux are deployed separately under the pass band of the existing CWDM filters. In principle, deploying the DWDM multi-channel Mux/Demux in the 1530nm channel can create 25 100 GHz spaced DWDM channels. However, only 19 DWDM channels circled in the following figure are suitable to be added in the hybrid CWDM-DWDM system. It is also the same to the 1550 channel. Hence, this hybrid CWDM-DWDM system totally offers 6 CWDM channels and 38 DWDM channels with less deployment cost but easier installation.

Conclusion

If you come across the capacity-hungry issue and can’t make the decision about which WDM system should be choose for increasing your network capacity, you are highly recommended to deploy a hybrid CWDM-DWDM system. As an economical and future-proofing solution, the hybrid CWDM-DWDM system can completely deal with the issue of bandwidth shortage when building a CWDM system and avoid the potential bankruptcy for a DWDM system. You can just deploy a CWDM system first. Once the capacity the CWDM system offers can’t meet your requirement, you can add DWDM equipment in for more channels to transmit signals. All in all, the hybrid CWDM-DWDM system is an ideal choice that not only costs less for deployment but keeps the flexibility to increase the network capacity.

[shinenewsposts-blog]

FS.COM 2017 – A Year Full of Gratitude and Appreciation

2018 is coming. At the end of 2017, Cable Gland with Strain Relief  FS.COM has reviewed the whole year and concluded a keyword “innovation and development”. In 2017, we continuously improve product quality and perfect service system to ensure products meet and exceed customer requirements. For instance, FS.COM FMT (multi-service transport) system is engineered to support low-cost 100G DWDM solutions for high-capacity optical links and conducive to save cabinet space. And on the basis of FHD (high-density) cable managing system, we self-developed the FHX system for ultra high-density cabling with easy management of MAC of connections in data centers as simple as plug & play.

In addition, FS.COM has completed the other product system like network switches, 25G transceivers & DAC/AOC, etc. With one year’s hard work, we got many positive comments from industry participants. Here just presents parts of the comments.There is a risk of buying network switches from vendor you haven’t used before or without feedback or recommendations from other people. However, you bought, and FS.COM didn’t let you down. FS.COM offers multiple types of optical transceivers ranging from SFP, SFP+, QSFP+ to 100G QSFP28 optics.

And every transceiver optics is individually tested on corresponding equipment to ensure its full compatibility on your devices. Moreover, we have different types of fiber cables and copper cables to meet various network demands.Last year, we built our USA warehouse to reduce the delivery time and this year, we have built the Germany warehouse and are expanding the European market. The following picture is one of our customers showing the transceiver optics and patch cables on Twitter. CWDM and DWDM Mux/Demux are used to increase the bandwidth of an optical fiber by multiplexing several wavelengths onto it, thus saving valuable optical fibers. We have CWDM Mux/Demux with 4 channels, 8 channels and 18 channels, and DWDM Mux/Demux with 8 channels, 16 channels, 40 channels and 96 channels, which can meet most network demands.

[gigalightoptics-blog]

CWDM and DWDM Comparison: What’s the Difference?

DWDM (Dense Wavelength Division Multiplexing) is undoubtedly the popular technology in today's optical fiber applications. However, because of its expensive price, many operators without enough money are quite hesitated to use it. Can we use wavelength division multiplexing at a lower cost? Faced with this demand, CWDM (Coarse Wavelength Division Multiplexing) came into being. And in the post, we will take an introduction on the main difference between CWDM and DWDM and which one is your better choice.

CWDM, as the name suggests, is a DWDM close relative. When comparing CWDM vs. DWDM, their differences are mainly two points as follows:

1. CWDM carrier channel spacing is wide, so the same fiber can only reuse 5 to 6 or so wavelength. This is why we call “Dense” and “Coarse”.

2. CWDM modulates laser by using non-cooling laser, but DWDM is used to cooling laser. The cooled laser is thermally tuned and the non-cooled laser is electronically tuned. Since the temperature distribution is very uneven in a wide wavelength range, the temperature tuning is difficult and costly to achieve. CWDM avoids this difficulty, therefore the cost is significantly reduced, the entire cost of CWDM system is only 30% of DWDM.

CWDM provides very high access bandwidth for low cost, and is suitable for popular network structures such as point-to-point, Ethernet, SONET ring, especially for short distance, high bandwidth, and point-intensive communication applications. Building communication between buildings or buildings. In particular, it is worth mentioning that CWDM and PON (passive optical network) with the use. PON is an inexpensive, point-to-multipoint optical fiber communication method. By combining with CWDM, each individual wavelength channel can be used as the virtual optical link of PON to realize the broadband data transmission between the central node and multiple distributed nodes.

At present, several companies are introducing CWDM-related products. Here we mainly introduce CWDM Mux/Demux and DWDM Mux/Demux.

(1). CWDM Mux/Demux Module:

CWDM Mux and CWDM Demux are designed to multiplex multiple CWDM channels into one or two fibers. The core of CWDM Module application is the passive MUX DEMUX unit. The common configuration is 1×4, 1×8, 1×16 channels. Available in 19″ Rack Mount or LGX module package, optional wide band port is available to multiplex with CWDM Channels wavelength.

(2). DWDM Mux/Demux Module:

DWDM Mux and DWDM DeMux are designed to multiplex multiple DWDM channels into one or two fibers. The common configuration is 4, 8, 16 and 40 channels. These modules passively multiplex the optical signal outputs from 4 or more electronic devices, send them over a single optical fiber and then de-multiplex the signals into separate, distinct signals for input into electronic devices at the other end of the fiber optic link.

However, CWDM is the product of cost and performance compromise; inevitably there are some limitations on performance. Industry experts pointed out that CWDM currently exist below the following four points: First, CWDM in a single fiber to support the number of multiplex wavelengths less, resulting in higher cost of expansion in the future; second, multiplexers, multiplexers, etc. The cost of the equipment should be further reduced, these devices can not only DWDM corresponding equipment, a simple modification; Third, CWDM does not apply to metropolitan area networks, metro nodes between the shorter distance, operators in the CWDM equipment expansion on the money can Used to lay more fiber optic cable, get better results; Fourth, CWDM has not yet formed a standard.

From the CWDM and DWDM comparison above, we can know both the benefits and drawbacks of CWDM and DWDM.  If the transmission distance is short and cost is low, then CWDM may be your first choice. On the contrary, you can consider DWDM. For more information about CWDM and DWDM, you can visit: Gigalight.

[dkphotonics]

Understanding the Use of Optical Fused Coupler, MUX & DEMUX WDM

In today’s high tech world, there is a desperate need for bandwidth.  The development of WDM (wavelength division multiplexing) technology has greatly helped us to expand the network capacity over a single fiber. A fiber optic coupler is a device used in fiber optic systems with input fibers (single or more) and output fibers (single or more). It is different from WDM devices.

The main benefits of Optical fused couplers are as follows:-

Combining: This Fiber Optic Couplers combine two signals and yield single output.

Splitting: The Splitters supply two outputs by using the single optical signal.

On the other hand, WDM multiplexer and demultiplexer divide the different wavelength fiber light into different channels. WDM is further divided into CWDM (coarse wavelength division multiplexing) and DWDM (dense wavelength division multiplexing). Generally, the WDM systems operate on 9µm single-mode fiber optical cables although it is not necessary.

If we specifically talk about the CWDM method, CWDM multiplexes multiple optical carrier signals on a single optical fiber. It uses different wavelengths/colors of laser light combined in a MUX in order to carry different signals. Mux/DeMux is one of the most important components of CWDM systems.

The LGX CWDM Mux and DeMux module comes with a 8 Channel (dual fiber) with 1U 19 Rack Mount Box that utilizes thin film coating technology and proprietary design of non-flux metal bonding micro optics packaging. It has been designed to provide optical networking support over a grid of CWDM optical wavelengths in high-speed Fibre Channel and Ethernet communication for metropolitan area networks (MAN).

The optical component is easy to operate with a reliable low-maintenance design. The MUX is passive and it does not use power supplies or electronics. It is capable of multiplexing and demultiplexing ITU-T G.694.2 wavelengths up to 8 channels in increments of 20nm from 1270 nm to 1610 nm. “ITU” specifies the exact center of 8CH CWDM Mux and Demux dual fiber 1U 19 Rack Mount Box wavelength such as 1531nm, 1591nm, 1611nm, etc.

The 8 Channel CWDM Mux and Demux dual fiber 1U 19 Rack Mount Box are protocol and rate transparent. They allow different services up to 10Gbps transported across the same fiber link. It works seamlessly with transceivers to optimize the link length, signal integrity, and overall network cost. It can be incorporated into a single rack-mount solution for a better design, power, and space efficiency.

As per the working principle, MUX and DEMUX can be used in various fields, such as communication systems, computer memories, telephone networks, etc. It is a cost saving method of connecting a multiplexer and a demultiplexer together over a single channel.

How to get the Optical Fused Couplers, Mux and DeMux WDM?

There are several leading companies in market that are considered masters at the designing and manufacturing of optical passive components for fiber laser, fiber sensor, and fiber optic telecommunication applications. One can contact these companies to avail high quality opticalcouplers, Mux and DeMux at affordable rates.

Contact a supplier today and get them.

[fiberopticslaura-blog]

How to Extend 40G Connection up to 80 km?

As 40G connectivity is accelerating, many data centers prepare to migrate from 10G to 40G. But the link distance between 10G and 40G switches is a big challenge. This article can help you extend 40G connection distance.

Current 40G QSFP+ Connection—Max 10 km

As we know, 40GBASE-SR4 QSFP+ is designed for short distance of up to 150m connection. 40GBASE-PLR4 QSFP+ can support long distance link of up to 10 km. Both 40G QSFP+ modules are interfaced with 12-fiber MTP/MPO and can break out into 4x10G connection. To build 10G-40G connection, for instance, using singlemode 8-fiber MTP-LC harness cable to connect 40GBASE-PLR4 QSFP+ and 4x10G SFP+ modules. As the direct connection distance between two 40GBASE-PLR4 QSFP+ optics can reach at most 10km, it’s easy to understand that the connection between 10G and 40G may be shorter. However, we provide a method to extend 40G connection to 80km distance. Continue to read this article and find the answer.

Equipment for Extending 40G QSFP+ Connection

To extend 40G QSFP+ connection distance, we have to use WDM transponder OEO (Optical-Electrical-Optical) repeater. OEO repeater allows connection between fiber to fiber Ethernet equipment, serving as fiber mode converter, or as fiber repeater for long distance transmission. It can also function as CWDM/DWDM optical wavelength conversion. Now we will use a multi-service transport system, including a hot-swappable plug-in OEO card which only occupies 1 slot. The other space can be left for holding more cards such as DCM, EDFA, OLP. On the left side, there is a card for centralized network management.

This is a 4-channel multi-rate WDM transponder with an OEO-10G card containing 8 SFP/SFP+ slots and can support up to 11.3G rate. The OEO card can convert 1G~11.3 Gbps Ethernet signals into a corresponding wavelength in CWDM and DWDM network infrastructures. Transmission distance can reach 80 km.

Except WDM transponder OEO repeater, we still need DWDM Mux/Demux and DWDM SFP+ to extend the distance to 80 km. DWDM Mux/Demux is to combine 4x10G signals of different wavelengths on one single fiber so that it’s the best solution to increase network capacity and save cost. Here we use 40-channel C21-C60 dual fiber DWDM Mux/Demux. So we can choose suitable 10G DWDM SFP+ modules 80km transceiver between the wavelengths of C21 and C60.

For your reference, the equipment for 40G connection extension mentioned above are from FS.COM. You can select those of other specifications according to your own needs.

Extend 40G QSFP+ Connection to 80 km

Install 40GBASE-PLR4 QSFP+ into QSFP+ port of a switch and 4 10GBASE-LR SFP+ into the Ethernet ports of the WDM transponder OEO repeater. Then plug a singlemode 8-fiber MTP-LC harness cable to connect 40GBASE-PLR4 QSFP+ and 4 SFP+ modules. Because of the OEO repeater function, 4x10G Ethernet signals are converted into corresponding wavelengths in DWDM network infrastructure. Then install 4 x 10G DWDM SFP+ transceivers into other four ports of OEO repeater. Next step is to connect DWDM SFP+ modules on the OEO repeater and DWDM Mux/Demux by using LC duplex patch cables. In this way, 40G QSFP+ distance can be extend up to 80 km.

Conclusion

10 km transmission distance is not the limit of 40G connection. From this article, you can extend 40Q QSFP+ to 80 km by mainly applying WDM transponder OEO repeater, DWDM Mux/Demux and 10G DWDM SFP+. If need to break your network distance limit, please visit our site www.fs.com or contact us via sales@fs.com.

Originally published at: http://www.fiber-optic-equipment.com.

[qing-chloe-blog]

Understanding WDM MUX/DEMUX Ports and Its Application

Wavelength division multiplexing (WDM) is a commonly used technology in optical communications. It combines multiple wavelengths to transmit signals on a single fiber. To realize this process, CWDM and DWDM mux/demux are the essential part. As we all know, there are several different ports on the WDM mux and demux. This article will give a clear explanation to these ports and their applications in WDM network.

Overview of Different Ports on WDM MUX/DEMUX

Line Port

Line port, sometimes also called as common port, is the one of the must-have ports on CWDM and DWDM Mux/Demux. The outside fibers are connected to the Mux/Demux unit through this port, and they are often marked as Tx and Rx. All the WDM channels are multiplexed and demultiplexed over this port.

Channel Port

Like the line port, channel ports are another must-have ports. They transmit and receive signals on specific WDM wavelengths. CWDM Mux/Demux supports up to 18 channels from 1270nm to 1610nm with a channel space of 20nm. While DWDM Mux/Demux uses wavelengths from 1470nm to 1625nm usually with channel space of 0.8nm (100GHz) or 0.4nm (50GHz). Services or circuits can be added in any order to the Mux/Demux unit.

Monitor Port

Monitor port on CWDM and DWDM Mux/Demux offers a way to test the dB level of the signal without service interruption, which enable users the ability to monitor and troubleshoot networks. If the Mux/Demux is a sing-fiber unit, the monitor port also should be a simplex one, and vice verse.

Expansion Port

Expansion port on WDM Mux/Demux is used to add or expand more wavelengths or channels to the network. By using this port, network managers can increase the network capacity easily by connecting the expansion port with the line port of another Mux/Demux supporting different wavelengths. However, not every WDM Mux/Demux has an expansion port.

1310nm and 1550nm Port

1310nm and 1550nm are one of WDM wavelengths. Many optical transceivers, especially the CWDM and DWDM SFP/SFP+ transceiver, support long runs transmission over these two wavelengths. By connecting with the same wavelength optical transceivers, these two ports can be used to add 1310nm or 1550nm wavelengths into existing WDM networks.

Application Cases of Different Ports on WDM MUX/DEMUX

Although there are several different ports on WDM Mux/Demux, not all of them are used at the same time. Here are some examples of these functioning ports in different connections.

Example One: Using 8 Channels CWDM Mux/Demux with Monitor Port

This example is a typical point-to-point network where two switches/routers are connected over CWDM wavelength 1511nm. The CWDM Mux/Demux used has a monitor port and 1310nm port, but the 1310nm does not put into use. In addition, an optical power meter is used to monitor the power on fibers connecting the site A and B.

Example Two: Achieve 500Gbps at Existing Fiber Network with 1310nm Port

In this example, two 40 channels DWDM Mux/Demux with monitor port and 1310nm port are used to achieve total 500Gbps services. How to achieve this? First, plug a 1310nm 40G or 100G fiber optical transceiver into the terminal equipment, then use the patch cable to connect it to the existing DWDM network via the 1310nm port on the DWDM Mux/Demux. Since the 1310nm port is combined into a 40 channels DWDM Mux, then this set-up allows the transport of up to 40x10Gbps plus 100Gbpx over one fiber pair, which is total 500Gbps. If use 1550nm port, then the transceiver should be available on the wavelength of 1550nm.

Example Three: Stack Two CWDM MUX/DEMUX Using Expansion Port

The connection in this example is similar to the last one. The difference is that this connection is achieved with expansion port not 1310nm port. On the left side in the cases, a 8 channels CWDM Mux/Demux and a 4 channels CWDM Mux/Demux are stacked via the expansion port on the latter Mux/Demux. And the two 4 channels CWDM Mux/Demux are combined with the line port. If there is a need, more Mux/Demux modules can be added to increase the wavelengths and expand network capacity.

Summary

Different ports on the CWDM and DWDM Mux/Demux have different functions. Knowing more their function is helpful in WDM network deployment. FS.COM supplies various types of CWDM and DWDM Mux/Demux for your preference. And customer services are also available. If you have any needs, welcome to visit our website www.fs.com.

Sources:http://www.fiber-optic-components.com/understanding-wdm-muxdemux-ports-application.html

[amiable-aria-blog]

Hybrid CWDM-DWDM System Boosts Your Network Capacity

Should I choose a medium capacity but more cost-effective CWDM solution, or to adopt the cost-prohibitive DWDM approach with comparably enhanced capacity? This is a problem that consistently faced by WDM technology users. The wrong decision, however, may inevitably lead to bandwidth shortage or even potential bankruptcy derived from unnecessary capacity investment. This article introduces the hybrid CWDM-DWDM solution that combines both CWDM and DWDM technologies within a single system, helping decrease costs and simplify installation while maintain the flexibility to upgrade.

Hybrid CWDM-DWDM System Explanation

Hybrid CWDM-DWDM system utilizes the technology to merge DWDM and CWDM traffic seamlessly at the optical layer. Which allows carriers to add many channels to networks originally designed for the more limited CWDM capacity and reach. In other words, hybrid CWDM-DWDM system is used to empower CWDM system by integrating CWDM and DWDM equipment. Hybrid CWDM-DWDM system deliver true pay-as-you-grow capacity growth and investment protection. It offers a simple, plug-and-play option for creating hybrid system of DWDM channels interleaved with existing CWDM channel plans.

Benefits of Hybrid CWDM-DWDM System

Hybrid CWDM-DWDM system typically provides three benefits for carriers and users:

Reduced Cost: CWDM is more cost-effective than DWDM due to the lower cost of lasers and the filters used in CWDM modules. This cost saving becomes quite significant for large deployments.

Pay-As-You-Grow: Adding one new channels at a time allows for on-demand service introduction with minimal initial investment—a critical feature in terms of reduced OPEX and CAPEX spending.

Investment Protection: Carriers and end-users need always to bear the future growth in mind. With hybrid CWDM-DWDM system, carriers no longer have to choose between CWDM and DWDM—both options can be deployed simultaneously or as part of future growth. This module can be used in either CWDM or DWDM system. Current capital investment can always be used in the upgraded network.

How to Deploy Hybrid CWDM-DWDM System

The CWDM wavelength grid typically has 16 channels spacing at 20 nm intervals, with 8 channels (1470 nm-1610 nm) of them are most commonly used. Within the pass band of these channels, it is capable of adding 25 100 GHz spaced DWDM channels under the 1530nm envelope and 25 more under the 1550nm envelope. However, it is not so practical to add 25 DWDM channels in the pass-band of both the 1530nm and 1550nm CWDM channels. DWDM filter technology does allow 38 additional channels to clear the CWDM archway, which is shown as following.

To add more DWDM channels to the MUX side of the conventional CWDM system, one need to plug in a DWDM MUX with the appropriate channels under the pass band of the existing CWDM filters. The picture below illustrates the configuration of a CWDM system upgraded with 38 additional 100 GHz spaced DWDM channels. This hybrid CWDM-DWDM system consists of 38 DWDM channels and the existing 6 CWDM channels. The equipment required to go from the first architecture to the second are 2 DWDM MUX/DEMUXs, as well as the additional transmitter and receiver pairs. The additional loss incurred by the upgrade is equal to the additional loss of the DWDM elements and the additional connection points.

Flexible Hybrid CWDM-DWDM System Solution by FS.COM

The most vital elements concerning hybrid CWDM-DWDM system are the CWDM MUX/DEMUX and DWDM MUX/DEMUX. FS.COM developed and introduces FMU series products to facilitate installation and operation of WDM MUX/DEMUX. The prominent feature of this series products is that they combine the MUX/DEMUX into half-U plug-in modules, which can be installed in a 1U rack. As for hybrid CWDM-DWDM system, a FMU CWDM MUX/DEMUX and a DWDM half-U plug-in module can be installed together in a FMU 1U rack chassis, facilitating connections of these two modules while allowing for better cable management and network operation in hybrid CWDM-DWDM system.

Conclusion

Hybrid CWDM-DWDM system generally offers a cost-effective and future-proofing approach for service providers and end-users, by overcoming the obstacles faced by users of WDM technology today, providing a starting platform that scales smoothly and protecting the investment. A user can commence with the more cost-effective CWDM technology and then later add DWDM in the when the capacity is required. FS.COM FMU series WDM solution makes the process even easier and more flexible. For more information, please visit www.fs.com or contact sales@fs.com.

Source: http://www.fiber-optic-solutions.com/hybrid-cwdm-dwdm-boost-network-capacity.html

[katherinewangfs-blog]

10G DWDM Network for Economically Expanding Capacity

It can’t be denied that for most users, the capacity and transmission data rate their 10G networks offer sufficiently meet their needs at present. However, for some users, their 10G networks are capacity-hungry that requires more and more fiber optical cables installed for carrying large data. Considering that the available fiber infrastructure is limited, the method of putting more cables would be infeasible or unsuitable once the infrastructure no longer fulfill the growing requirements. Is there any economical solution to solve this issue, except upgrading the network that would cost a lot? The answer is yes. In order to create new capacity at a relatively low price, WDM technology is come up with that enables virtual fibers to carry more data. Since WDM technology has been a cost effective solution to face the capacity-hungry issue, here will offer the economical DWDM SFP+ transceiver and DWDM Mux Demux solutions for you to build the 10G DWDM network, which enables bigger capacity to meet your network needs.

DWDM SFP+ Transceiver

The DWDM SFP+ transceiver is an enhanced version of DWDM SFP transceiver that can transmit signals at 10Gbps–the max data rate, mostly deployed in the dark fiber project in combination with the DWDM Mux Demux. Like other kinds of SFP+ transceivers, it is also compliant to the SFP+ MSA (multi-source agreement), designed for building 10G Ethernet network. However, the working principle of DWDM SFP+ transceiver is much more complicated than that of common SFP+ transceiver due to the DWDM technology.

Generally, the DWDM SFP+ transceiver has a specific tuned laser offering various wavelengths with pre-defined “colors” which are defined in the DWDM ITU grid. The colors of the wavelengths are named in channels and the wavelengths are around 1550nm. Its channels are commonly from 17 to 61 and the spacing between channels is always about 0.8nm. In fiber optical network, the 100GHz C-Band with 0.8nm DWDM SFP+ transceiver is the most commonly used one, while transceivers with other spectrum bands like 50GHz with 0.4nm spacing DWDM SFP+ transceiver are also popular with users.

According to the transmission distance, the DWDM SFP+ transceiver can be divided into two types. One is the DWDM-SFP10G-40 with an optical power budget of 15dB, and the other is the DWDM-SFP10G-80 with an optical power budget of 23dB. As we know, the bigger the optical power budget is, the longer the transceiver will support the 10G network. Hence, the DWDM-SFP10G-40 can transmit 10G signals at lengths up to 40 km, but the DWDM-SFP10G-80 is able to support the same network with a longer distance, 80 km. What should be paid attention to is that the transmission distance can be also affected by the quality and type of the DWDM Mux Demux, the quality and length of the fiber, and other factors.

DWDM Mux Demux

The DWDM Mux Demux is a commonly used type of fiber optical multiplexer designed for creating virtual fibers to carry larger data, which consists of a multiplexer on one end for combining the optical signals with different wavelengths into an integrated signal and a de-multiplexer on the other end for separating the integrated signal into several ones. During its working process, it carries the integrated optical signals together on a single fiber, which means the capacity is expanded to some extent. In most applications, the electricity is not required in its working process because the DWDM Mux Demux are passive.

Unlike the CWDM Mux Demux with 20nm channel spacing, the DWDM Mux Demux has a denser channel spacing, usually 0.8nm, working from the 1530 to 1570nm band. It is designed for long transmission, which is more expensive than CWDM Mux Demux used for short transmission. Meanwhile, it also commonly used the 100 GHz C-band DWDM technique like the DWDM transceiver. As for its classification, there are basically two types according to line type, dual fiber and single fiber DWDM Mux Demux, and six types according to the number of the channels, 4, 8, 16, 40, 44 and 96 channels DWDM Mux Demux. All these types of DWDM Mux Demux are available at FS.COM with ideal prices. To better understand the DWDM Mux Demux, here offers a figure of a stable 8 channel DWDM Mux Demux for your reference.

Conclusion

Taking the cost issue into consideration, deploying a 10G DWDM network is much more economical than upgrading your network from 10G to 40G/100G which almost requires changing out all the electronics in your network. The 10G DWDM network makes full use of DWDM technology to expand the network capacity, which creates virtual fibers to support more data signals. If your 10G network is also capacity-hungry, you are highly suggested to deploy 10G DWDM network to make new capacity. As for the related components the 10G DWDM network needs like transceiver and Mux Demux, you can easily find them at FS.COM. For instance, FS.COM offers the DWDM SFP+ transceivers compatible with almost every brand, including Cisco, Juniper, Brocade, Huawei, Arista, HP and Dell, which have been tested to assure 100% compatibility.

Originally source: http://www.chinacablesbuy.com/10g-dwdm-network-for-economically-expanding-capacity.html

[katherinewangfs-blog]

Analysis of Power Budget and Link Distance in CWDM System

It can’t be denied that CWDM technology is a cost effective method to increase the capacity in the existing system, which can give different wavelengths to multiple optical signals and multiplex them for transmission through only one single fiber. Different from the DWDM system, the network using CWDM technology are deployed by passive components like passive CWDM Mux Demux, without the need of additional power, which makes CWDM system more commonly used. Do you also plan to build a CWDM system? If yes, you can check the following information for reference, which mainly analyzes the optical power budget in a CWDM system and calculates the CWDM link distance according to the power budget for smoothly deploying a CWDM system.

What’s Optical Power Budget?

Before deploying an optical network, it is very essential to calculate the optical power budget for better deployment. What’s optical power budget? It is just the amount of light available to make a successful fiber connection which can be calculated by analyzing the original output power of the transmitter and the required input power of the receiver. In details, we should firstly learn the optical power that is emitted by the source (also referred to Transmit Power) and the required power of the detector (also called Receiver Sensitivity). Using the first data to subtract the second one, you’ll get the data of the optical power budget which greatly determines the performance of the whole network link.

Here is the equation: Optical Power Budget = Transmit Power - Receiver Sensitivity.

How to Get the Optical Power Budget in a CWDM System?

To estimate the link distance supported by a CWDM system, the optical power budget should be calculated first, which can greatly determine the CWDM link distance. Here will show you a basic CWDM system under an ideal condition to clearly illustrate how to get the optical power budget. In this basic CWDM system, there is a optical transmitter which transmit power is -2 dBm and a optical receiver with -25 dBm receiver sensitivity. Hence, the optical power budget is 23 dB, as shown in the following equation.

Optical Power Budget = Tx Power - Rx Sensitivity = -2 dBm - (-25 dBm) = 23 dB

However, the mentioned CWDM system is just under an ideal condition without loss caused by the signal transmission. In a normal CWDM system, there are many components like passive CWDM Mux Demux, CWDM transceiver inserted. All these components cause insertion loss once they are inserted into the CWDM link. Therefore, when doing the optical power budget, all the loss should be taken into account for calculating the power budget exactly.

Here is more exact equation: Power Budget = Tx Power - Rx Sensitivity - Loss

To get the real power budget of a CWDM system, here offers a simple CWDM link which uses the -2 dBm optical transmitter, -25 dBm optical receiver and four passive CWDM Mux Demux with low insertion loss. Both the stable 4 channel CWDM Mux and stable 4 channel CWDM Demux in the link have 2.0 dB insertion loss, and other two are 8 channel ones feature 2.5dB insertion loss separately, as shown in the figure below. As a result, the total loss caused by the four passive CWDM Mux Demux is 9 dB, resulted from 2.5 dB + 2.0 dB+2.5 dB + 2.0 dB. Then we can get the total power budget, 14 dB. The calculation process is: Power Budget = Tx Power - Rx Sensitivity - Loss = -2 dBm - (-25 dBm) - 9 dB = 14 dB

How to Calculate the Link Distance in the CWDM System?

After knowing the optical power budget, let’s calculate the link distance of the CWDM system according to the following equation: Link Distance = Optical Power Budget/Fiber Attenuation. As there may be some other power loss caused by the factors that we didn’t consider like fiber aging, temperature and poor splice, we often subtract 2 dB buffer from the total optical power budget. Meanwhile, the fiber attenuation is changeable according to the wavelength, usually varying from 0.2 to 0.35 dB/km. In this case, we’ll use 0.35 dB/km as a typical data. Then we can get the link distance is about 34 km. The calculation process is Link Distance = Optical Power Budget/Fiber Attenuation = (14 dB- 2 dB)/0.35 dB/km.

Conclusion

This paper intends to illustrate how to calculate the optical power budget and estimate the link distance of a CWDM system according to the optical power budget, which allows for better budget of deploying the CWDM system and eliminates the unwanted or unnecessary issues which may happen in the system deployment. Besides, if you want to make a cost effective CWDM system, you are suggested to buy CWDM components like cheap passive CWDM Mux Demux, CWDM transceivers from FS.COM, which are of good price and quality.

[katherinewangfs-blog]

What Can CATV Systems Benefit from EDFA Optical Amplifiers?

As long-distance transmissions are always required in the CATV systems, it is very necessary to make the quality of visual and audio signals in high levels after the long transmissions, so that the performance of the CATV systems can be ensured. To serve this aim, the CATV EDFA optical amplifiers are come up with and widely used in the CATV systems. Why the EDFA optical amplifier is needed in CATV system? How does it work for the long CATV application? The following text will give you the answers and simply introduce two typical CATV EDFA amplifier applications for your reference.

What’s CATV EDFA Amplifier?

CATV EDFA is a kind of optical amplifier, most commonly used in the long-haul CATV system for boosting the damped CATV signals, with the aim of compensating the signal loss. Since it mostly works as booster optical amplifier in the CATV system, so that it can be also called CATV booster amplifier. By utilizing the CATV EDFA optical amplifier, the CATV signals can be enhanced to meet the system requirement and then be sent to the users. However, when the signal power is improved by the CATV EDFA, the noise existing in the transmission link would also boosted and some return loss would also occur at the same time. Considering that, it is very necessary to choose quality CATV EDFA optical amplifier for ensuring the performance of CATV system, even if it may be cost a little higher than common optical amplifier.

Why CATV EDFA Optical Amplifier is Used?

CATV is a multi-channel TV system transmitting visual and audio signals from digital or analog television and radio channel to many users via fiber or copper patch cable. As the signals should be finally separated by optical splitter to serve more than one users and many loss has occurred in the long transmission, the overall speed and quality of the CATV signals would become too weak to meet the receiver requirements. Under this condition, the CATV EDFA optical amplifier is very essential for CATV system with the function of amplifying CATV signals and giving high performance systems to the users.

How Does CATV EDFA Work for Long CATV Applications?

A long CATV system is always composed of head end, transmitter, receiver, CATV booster amplifier and optical splitter. When the system runs, the CATV signals are provided by the head end, and need to be split into several signals by the optical splitter to serve the users. When the signals pass through the optical splitter, the signal power would be in a very low level. Hence, the CATV EDFA optical amplifier should be deployed after the receiver to improve the signal power, and the users can finally receive quality signals.

From the figure above, we can learn a simple point-to-multipoint CATV network design as mentioned above. The CATV signals are provided by the RF combiner and should be connected with four receivers by the optical splitter. In order to compensating the signal loss caused by the optical splitter, CATV EDFA optical amplifier is required before sending the weak signals to the users.

Except for this simple kind of CATV network using CATV EDFA optical amplifier, here also offers a complex CATV network, as designed in the figure below. In this CATV network, the CATV EDFA optical amplifier is deploy behind the 8 channel DWDM Mux Demux to amplify the signals while the 8 channel DWDM Mux Demux allows for higher capacity transmission. Hence, a long CATV network with big capacity can be achieved.

Conclusion

When deploying a long CATV system, we should pay attention to the loss caused by long transmission distance and CATV components. When the loss is very high, CATV EDFA optical amplifier would be an ideal device deployed in the long CATV system for improving the quality of CATV signals, so that the users can receive high speed and reliability of the services.

[katherinewangfs-blog]

Why Not Build a 10G CWDM Network for Higher Capacity?

Although the 40G and 100G technologies develop vigorously recent years to meet the increasing need of higher capacity, they are still not widely accepted and applied due to high deploying cost. Under this case, choosing to build a 10G network is always the first choice for most users. But except upgrading our system, what else can we do when the 10G network can’t offer enough capacity? To address this issue, telcom engineers and researchers suggest that we can deploy the 10G CWDM networks. With use of CWDM optical multiplexer, this solution offers a highly cost effective method to gain more capacity on the basis of 10G network. Let’s study the benefits of 10G CWDM network and its two basic common network infrastructures in details.

What Can We Benefit from 10G CWDM Network?

In contrast to 10G DWDM network, 10G CWDM network can neither offer so high data capacity nor transmit the signals so long. But on the other hand, 10G CWDM network is an easier-to-deploy and less expensive solution that can well serve for a wide range of optical applications. Let’s study the main benefits of 10G CWDM networks.

It is possible to add connections for transmitting more data in 10G network, which makes the whole network load increasing from 10G to 40G or 100G possible.

CWDM Mux Demux is the key component of 10G CWDM network. As a passive component, it doesn’t require extra power, which is an ideal option for deploying 10G CWDM network.

Instead of upgrading system, deploying 10G CWDM network to get more capacity can saves a lot of money due to the economical 10G hardware and cheap passive CWDM Mux Demux.

Understanding Common 10G CWDM Network Infrastructures

10G CWDM system is a passive optical network, which supports 10G transmission with any protocol over the optical link, as long as the 10G signals are at the specific CWDM wavelengths. At present, there are two common CWDM network infrastructures. One is 10G CWDM point-to-point network, and the other is 10G CWDM ring network. The following will introduce the two common infrastructures in details.

10G CWDM Point-to-Point Network: it is the simplest network infrastructure of the CWDM networks. As shown in the following figure, there are two passive CWDM Mux Demux deployed in the 10G network that offers 8 channels to multiplex the signals from 8 different optical fiber link into an integrated signal. Thereby, the signal can be transmit through only one fiber, which means there are 7 virtual fiber created with higher capacity for transmitting more data. As for the cheap passive CWDM Mux Demux, it can be available at very good price that costs less than upgrading the system from 10G to 40G or 100G. Undoubtedly, deploying a 10G CWDM point-to-point network is very economical solution for higher capacity.

10G CWDM Ring Network: it is deployed on the basis of 10G CWDM point-to-point network. Compared to point-to-point network, the ring network is much more complex that needs other optical CWDM components like CWDM OADM. By adding CWDM OADM, two or more point-to-point network can be connected together, which can finally achieve a 10G CWDM ring network. To better understand how does the 10G CWDM ring network work, here offer a figure that shows four buildings are connected by several 8 channels CWDM Mux Demux and CWDM OADM for your reference.

Conclusion

Unlike upgrading the network from 10G to 40G or 100G, building a 10G CWDM network doesn’t requires changing all the network equipment which may cost highly. It only need CWDM transceiver and CWDM Mux Demux to be deployed in the original 10G network. For a complex 10G CWDM network, additional optical equipment like CWDM OADM are required. If you come across the capacity-hungry issue, building a 10G CWDM network would be a nice option for higher capacity.

[katherinewangfs-blog]

How to Extend Your Network Transmission Distance?

To face the need for long-haul, high-capacity transmission, experts come up with several DWDM projects including DWDM Mux Demux, EDFA amplifier (erbium-doped fiber amplifier) and DCM module (dispersion compensation module) to expand network capacity and enhance the signal power, which can greatly extend the optical network reach. Do you have the need to deploy a longer fiber optical transmission link? If yes, you can just build a DWDM system with the DWDM projects mentioned above. This paper will introduce three solutions that utilize these DWDM components to extend the optical network transmission distance. Hope these DWDM solutions would be useful for you.

Using DWDM Mux Demux for Long Transmission up to 50 km

DWDM technology plays an important role in building long-haul transmission system, which enables multiple signals with different wavelengths to be transmitted through only one single fiber. To build a long system with DWDM technology, the DWDM Mux Demux is an indispensable component that features low insertion loss and polarization-dependent loss. By using the DWDM Mux Demux in your network, the signal transmission distance can be extended to up to 50 km. To better know the advantage of DWDM Mux Demux, here offers an example that uses two 8 channel DWDM Mux Demux for extending the optical fiber link.

From the figure, we can learn that at the transmit side, eight kinds of signals from different fiber links are multiplexed into an integrated signal by the 8 channel DWDM Mux. Then the integrated signal is transmitted over the single mode fiber (SMF) and the maximum transmission distance can be up to 50 km. At the receiver side, the signal will be demultiplexed into individual signals with their original wavelengths by the 8 channel DWDM Demux and then transmitted to another eight different fiber links. Just by using the DWDM Mux Demux, a 50km long-haul transmission can be simply achieved.

Adding EDFA Amplifier for Transmission Longer Than 50 km

As we know, the longer the transmission distance is, the higher the fiber loss will be. Hence, except for the DWDM Mux Demux, you are suggested to add an EDFA amplifier to the long fiber link if the transmission distance is longer than 50 km. What’s the function of EDFA amplifier? It is mainly designed to amplify the signal power, which enables longer transmission. As shown in the following figure, you can learn that the only difference is the EDFA amplifier in the SMF, compared to the first solution.

When the integrated signal multiplexed by the 8 channel DWDM Demux is transmitted over the SMF, it would become too weak in the transmission process to be transmitted. Then the EDFA amplifier should be placed there to boost the signal power, supporting the transmission longer than 50 km. Once the long transmission is realized, the signal will be also split by the 8 channel DWDM Demux, like the first solution. In short, DWDM Mux Demux and EDFA amplifier are highly suggested if you want to deploy a DWDM system longer than 50 km.

Adding DCM Module for Transmission up to 200 km

With the use of EDFA amplifier, the DWDM fiber link can be extended to 200 km. However, the signal quality is always unsatisfied due to the optical dispersion in long transmission, especially in CATV systems. To meet high requirements of the signal quality in these long transmission systems, an additional optical component, DCM module are needed in the long fiber link, as deployed in the figure below.

From the figure, we can learn it is a long-haul point-to-multipoint CATV system. To extend the transmission distance, 8 channel DWDM Mux Demux, EDFA amplifier are used. Except for that, a DCM module is added to enhance the skew signal for ensuring the whole transmission quality. With the use of DCM module, the accumulated chromatic dispersion issue is solved, without dropping and regenerating the wavelengths on the long fiber link. Thereby, a high-performance 200km system can be reached.

Conclusion

DWDM projects including DWDM Mux Demux, EDFA amplifier and DCM module are key optical components to support long-haul transmission systems. If you want to deploy a long transmission system up to 50 km, then the DWDM Mux Demux is needed. For transmission longer than 50 km, both the DWDM Mux Demux and EDFA amplifier are required for boost the signal power. But once the transmission distance is about 200 km, you should additionally add the DCM module to enhance the signal quality.

[qing-chloe-blog]

Application Cases of 10G CWDM Network

CWDM network, as an easy-to-deploy and cost-effective solution, has been applied in many areas. Although CWDM network is not as perfect as DWDM networks in data capacity, it still can satisfy a wide range of applications in optical applications. And CWDM is a passive network, allowing any protocol to be transported over the link, as long as it is at the specific wavelength. This article is going to describe several application cases of 10G CWDM networks in different areas.

Benefits of 10G CWDM Network

Although 40G and 100G networks are developing rapidly, many of them still need to grow on the basis of 10G networks. And due to the high cost of 40G and 100G, 10G networks are still the most common networks to be deployed. Here are the main benefits of 10G CWDM networks.

CWDM Mux/Demux is a passive component and requires no extra power, offering a cost-effective choice for network designers.

Increased network connections and easy to evolve from 10G to 40G and 100G networks. For example, 10G CWDM network can combine DWDM wavelengths using the 1550nm channel on CWDM Mux/Demux. And if an operator want to upgrade its 10G network to 40G or 100G, there are various fiber components in market that can help him realize this conversion.

Lower cost. 10G hardware has become cheaper, which make 10G CWDM network more economical. For example, buying one pcs 8 channels CWDM Mux/Demux which is the most often used in CWDM networks needs less than 330 dollars in some stores. And 10G CWDM optical transceivers are also very cheap now.

10G CWDM Network Infrastructure

As has mentioned above, 10G CWDM network has been widely deployed in different areas. Here are the common CWDM network infrastructures.

Point-to-point 10G CWDM Network

A point-to-point CWDM network is the simplest network structure of CWDM networks, but it is the basis of other complex network infrastructures. By adding other components like CWDM OADM, the point-to-point CWDM network is easy to be changed into more complicated networks. The following figure shows a point-to-point CWDM network using 8 channels CWDM Mux/Demux.

10G CWDM Ring Network

CWDM ring links are suitable for interconnecting geographically dispersed LANs and storage area networks. Business can benefit from CWDM by using multiple Gigabit Ethernet. As shown in the below picture, the four buildings are connected by several 8 channels CWDM Mux/Demuxes.

Application Cases of 10G CWDM Network

Applications in Service Providers

CWDM uses different wavelengths to carry different signals over a single optical fiber, which offers many benefits to service providers that need to better utilize the existing fiber infrastructure. In this application, two Cisco switches are connected together through four 8 channels CWDM Mux/Demuxes. Signals are multiplexed and then transmitted through two strands fiber cables.

10G CWDM Application in Campus Network

As the scale expansion of many campus, the need for adding bandwidth of new applications is increasing too. And the new campus, school teaching and student life Internet require a lot of bandwidth resources, so building a new network is undoubtedly needs a large investment. Then how to make a full use of existing fibers is a problem needed to be resolved.

In this case, four 8 channels CWDM Mux/Demux with expansion port are used to double the capacity on the existing fiber without the need for installing or leasing additional fibers, which reduce cost and labor.

Summary

As the development of WDM technology and market, the deployment of CWDM network will be more lower. FS.COM provides affordable CWDM network components at a low price. Following is a list of our products.

Product ID    Description

42945        8 channels 1290-1430nm dual fiber CWDM Mux Demux 

43099        8 channels 1470-1610nm dual fiber CWDM Mux Demux with expansion port 

19367        Cisco Compatible 10G CWDM SFP+ 1470nm 80km DOM Transceiver 

31290        Cisco Compatible 10G CWDM SFP+ 1290nm 40km DOM Transceiver 

Sources: http://www.fiber-optic-components.com/application-cases-10g-cwdm-network.html

[qing-chloe-blog]

How to Calculate Power Budget and Link Distance in CWDM Network

By multiplexing separated wavelengths from multiple ports onto a single fiber in the network, coarse wavelength division multiplexing (CWDM) network increases fiber capacity at a low cost. And all the CWDM components are passive and do not need power, which requires lower investment than DWDM networks and make it popular. This article intends to explore how to calculate the power budget and link distance in CWDM network, offering more conveniences for your CWDM network deployment.

Understand Optical Power Budget in CWDM system

One important factor of network design, including various optical networks like DWDM and PON, is the optical power budget. Optical power budget is the amount of light available to make a fiber optic connection. The difference between the output power of the transmitter and the input power requirements of the receiver is referred to as the power budget. The power budget with various losses in an optical fiber, as shown in the picture below, is obtained by first determining the optical power emitted by the source, usually expressed in dBm, and subtracting the power (expressed in same units, e.g., dBm) required by the detector to achieve the design quality of performance (Receiver Sensitivity). Here is a common equation that can be used to calculate the power budget in a decided length fiber link.

Link Power Budget = Min Transmit Power - Min Receiver Sensitivity

Calculate Power Budget in CWDM Network

When designing a CWDM network, power budget is often used to determine the maximum distance that a link can support. The transmission power budget is the difference between the optical transmitter output power and the receiver sensitivity. In order to explain the calculation process clearly, all the equations will be given an example for illustrating.

Power Budget = Tx Power - Rx Sensitivity.

Example one. A -2 dBm optical transmitter and a -25 dBm receiver provide a total transmission power budget of 23 dB.

Power Budget = Tx Power - Rx Sensitivity = -2 dBm - (-25 dBm) = 23 dB

As we all know, in a CWDM system, CWDM Mux/Demux, CWDM OADM and other components are common. And each one of them will introduce loss once added into the CWDM system. For example, when using a CWDM OADM in CWDM network, the point where a channel is dropped, added, or passed will cause a loss of signal strength. Therefore, when calculating power budget for a CWDM link, all losses must be added together. As shown in the following equation.

Power Budget = Tx Power - Rx Sensitivity - Losses

Example two. Here is a link A shown as below. There are four CWDM Mux/Demuxes and two CWDM SFP transceivers in this link. The Mux/Demux #1 and Mux/Demux #4 are 8-channel CWDM Mux/Demux. The left two is 4-channel CWDM Mux/Demux. Link A is the distance from CWDM SFP #1 and CWDM SFP#4. Each CWDM Mux/Demux has a low insertion loss. For instance, the insertion loss of the 8-channel CWDM Mux/Demux is less than 3.1dB (including connectors and adapters).

Here is the calculating process.

Power Budget = Tx Power - Rx Sensitivity - Losses

Tx Power = 2 dBm

Rx Sensitivity = -23 dBm

Losses = (8-channel Mux/Demux #1 loss) + (4-channel Mux/Demux #2 loss) + (4-channel Mux/Demux #3 loss) + (8-channel Mux/Demux #4 loss)

= 2.5 dB + 2.0 dB + 2.0 dB + 2.5 dB = 9.0 dB

Power Budget = Tx Power - Rx Sensitivity - Losses = 2 dBm - (-23 dBm) - 9.0 dB = 16 dB

Calculate Maximum Link Distance in CWDM Network

After determining the power budget for a fiber link, we can use the value to calculate the maximum distance that the link can support. The calculation equation is shown as below.

Power Budget = Buffer Distance/Fiber Attenuation

Usually, a buffer of 2 dB is subtracted from the power budget to account for other factors that may affect the loss of transmission power. These factors include fiber aging, temperature, poor splice, etc. Fiber attenuation is the loss of signal strength as it travels through the fiber. The attenuation varies with the wavelength. Typical values are 0.2 to 0.35 dB/km.

Then we will calculate the maximum supported distance of link A in example two. Here we take the worst value for the fiber attenuation. The distance is:

Distance = (18 dB-2 dB)/0.35dB/km = 40km

The maximum supported distance of link A is 40km.

Summary

Knowing how to calculate the power budget and transmission distance can help engineers estimate the CWDM network deployment cost, and also can avoid some unnecessary problems in network design. This post gives a clear illustration to calculate them. Hope it would help you. In addition, FS.COM is a professional manufacturer and supplier of optical components. If you have any need, welcome to visit our website www.fs.com.

Sources:http://www.fiber-optic-components.com/calculate-power-budget-link-distance-cwdm-network.html