#dwdm network

I want to share some information about configuring 10G services in differenet forms in DWDM network.

1.What are the differences between 10GE LAN and 10GE WAN services

According to IEEE 802.3ae,  compared with 10GE LAN services,10GE WAN services involve an additional   process in which signals are encapsulated into standard SDH/SONET frames. In other words, 10GE WAN services are processed in a similar way as how STM-64 services are processed in a   WDM/OTN system.The most direct difference between 10GE LAN and 10GE WAN services is that they have different signal rates.

2.How do we configure 10GE LAN and 10GE WAN services?

Let's take a look at the steps for configuring 10GE WAN services.

3 - About the 10G LAN there are 2 types of  port mapping ((bit transparent mapping and MAC transparent mapping))

What is the difference between bit transparent mapping and MAC transparent mapping?

In bit transparent mapping (11.1G) mode, the OTU frame frequency is increased to ensure the encoding gain and error correction capability of the FEC function.Therefore, the service rate is OTU2e,which is higher than OTU2. This mapping mode is recommended for interconnection between Huawei devices.

In MAC transparent mapping (10.7G) mode, the GFP-F encapsulation mode is used to map 10GE MAC frames into OTU2 signals.

This mapping mode provides a standard service rate and therefore facilitates interconnection between Huawei devices and peer devices.

Nowadays, DWDM technology has been one of the most commonly used technology in optical transport network (OTN) applications due to the increasing bandwidth need of telecommunication providers. Faced with unpredictable traffic requirements and increasing bandwidth demands, FS has developed a new standardized optical transport solution, which called FMT WDM transport platform. And this FMT WDM transport platform  is divided into four specific series according to different transmission distance, including CWDM solution FMT 1800, DWDM solution FMT 1600E, 4000E, 9600E. In this post, we will take FMT 4000E optical transport platform as an example to illustrate how does this transport platform realizes 100km network connections and its advantages.

What Is FMT 4000E DWDM Network Transport Platform?

As mentioned above, FMT 4000E DWDM network transport platform is one type of the FMT WDM transport platform series. This optical transport platform is a 4U managed chassis. It is equipped with 16 full-size slots and optical layer modules and a wide range of intelligent services modules can be installed in these slots. Equipped optical devices in FMT 4000E will be illustrated in detail in the following part.

Currently, FS has developed two versions FMT 4000E, but these two versions has different transmission. One version can support 160km transmission, while another can support 100km transmission. And this post will focus on FMT 4000E for 100km. This platform can achieve 100km end-to-end dual fiber bidirectional transport and support up to 40 wavelengths from C21-C60 at 100GHz. In addition, this optical transport platform can be applied in metro/regional networks, such as CATV, FTTH/PON, xDSL triple play services, GSM/3G mobile services, business customers storage services and so on.

How Does the DWDM Network Work By Using FMT 4000E

From the above topology, we can find that the optical signal from the switch will be sent to 40CH DWDM MUX DEMUX at Site A for wavelength division multiplexing. And then the optical power will be lowered by using optical attenuator. And the dispersion will be compensated by DCM. When this process is finished, the booster amplifier (BA) will improve the optical power and extend the transmission distance. After 100km fiber transmission, we need to amplify the signal by using pre-amplifier (PA) and then the optical signal will be compensated by DCM again. At this time, the optical signal will be sent to 40CH DWDM MUX DEMUX at Site B for demultiplexing again. Finally, the optical signal will be sent to the switch.

Why Choose This FMT 4000E DWDM Transport Platform？

This FMT 4000E DWDM transport platform has flexible networking because it is equipped with intelligent DWDM MUX/DEMUX, integrated with DWDM EDFA and DCF-based DCM system management. This platform has high channel density because it has up to 40 DWDM channels. And this platform can achieve 100km end-to-end dual fiber bidirectional transport when the fiber link loss is 0.25dB/km and the fiber type is G.652D. In addition, this platform has monitor online management software, which can allow operators and administrators to monitor the performance of the whole network. When the urgent accident occurs, this network management system can notify the user so as to ensure the safety of the network. This system can also provide real-time management for local and remote network. Besides, it will send email to inform you of the performance of the network.

Conclusion

In order to research the present situation and the existing problems about CEDM technology, Fiberstore invited some equipment manufacturers include Huawei, Shanghai bell alcatel(asb), CIENA, light bridge, Fire network to test CWDM equipments. Main test content includes: Main optical channel MPI interface, OTU testing, business interface testing (including SDH, Ethernet, transparent rate channel interface, ESCON, etc.); Networking ability tests (including CWDM OADM ring type network, point-to-point, chain type, bi-directional single fiber, etc.), optical layer protection function test, network management function test, reliability (high and low temperature, humidity, vibration, etc.) and equipment safety testing. Through this test, we find the current CWDM technology has the following main features:

1. As a result of E band optical transceiver module technology is not mature, so the vast majority of products are 8 (1470 nm to 1610 nm), because of CWDM technology located in the edge of the metropolitan area network layer, so the related products are designed as cartridge products, and And you can expand conveniently through the cascade.

2. CWDM support point to point, the chain of chain shaped, ring, ring, bi-directional single fiber and other network mode, It can be flexible to use according to requirements.

3. In general it supports MUX line side to choose 1+1 optical line protection, and OTU layer 1 + 1 optical channel protection through the special protection board.

4. Because of variety of the metropolitan area network business, such as GE, SDH, FE, ESCON, FICON, FC, etc., and rate may reach to 100 Mbit/s~2.5 Gbit/s, protocol transparency and rate of transparency of CWDM make it can be a very good offer for the transmission function of metropolitan area business.

5. Many vendors begin to support electricity layer reuse of business functions, such as Shanghai bell can be 622 m below the rate of different formats of signal multiplexing for 4 x Any board of STM-16 signal, Huawei GEMUX plate can multiplex 2 GE or FC for STM-16.

6. CWDM network management system of performance management and fault management and configuration management exist the problems of weak ability, it need to further improve.

7. The reliability and safety of some CWDM device still exist some shortcomings, such as lack of ALS or APR function, the reliability of the optical transceiver module still needs improvement. These problems are the result of the emphasis on cost reduction.

CWDM technology’s biggest problem is that its cost advantages relative to the DWDM Equipment is still not enough. Optical transceiver modules and optical devices is the key to reduce costs. But due to the small market, supplier shipments is not big, so the device cost advantage is not obvious. Another way to reduce the cost is simplified the function of devices, and this method results in the decrease of system reliability and the management ability. DWDM Price is more and more lower also bring a lot of pressure to CWDM technology, and now use the DWDM technology can form a complete metro DWDM Network, so good scalability, the pressure bring to CWDM is larger. Now CWDM device support the number of optical CWDM channels ( CWDM wavelengths) no more than 8, main reason is that E band optical transceiver module manufacturing process is not yet mature, in addition, eliminating the water absorption peak of G.652 c cables in the application is less, so the market demand for E band optical transceiver module is not big. Higher rate and further transmission distance of CWDM system still have many technical problems. Such as CWDM 10G system dispersion problem, ultra broadband optical amplification technology, etc. In addition, it need to speed up the standardization process, especially it need operators’ guidance in the business interface function aspect.

If you have some needs to buy related CWDM/DWDM optical fiber products, advise you to a professional store to get them. Fiberstore is just a quite right choice.

We all have a knowledge of CWDM VS DWDM technology. but how to choose suitable solution is what we need to know. As we know, because of its costs, DWDM is more suited to longer-reach applications if developers begin to value the real requirements are in the metro access/metro core space. DWDM is a useful solution for high-growth routes that have an immediate need for additional bandwidth. According to vendors, carrying that are building or expanding their long distances networks could find DWDM to be an economical way to incrementally increase capacity, rapidly provision needed expansion, and “future-proof” their infrastructure against unforeseen bandwidth demand.

DWDM is well suitable for long-distance telecommunications operators when we use either point-to-point or ring topologies. The availability of 16, 32, or 64 new transmission channels, where there used to be one, improves an operator’s ability to expand capacity and simultaneously set aside backup bandwidth without installing new fiber. Proponents make the case that this large amount of capacity is critical to the development of self-healing rings. By deploying DWDM terminals, an operator can construct a protected 40 Gbps ring with 16 separate communication signals using only two fibers. However, unless there is a major underlying engine continuously driving the demand through the roof, this kind of technology is a “one-time (in a long time) upgrade,” with obvious market-sizing implications.

There has been a lot of hype in the recent past about metro DWDM network, Some supporters of DWDM claim that the acceptance of the technology will drive the expansion of the optical layer throughout the whole telecommunications network and allow service providers to exploit the bandwidth capacity that is inherent in optical fiber,But at present there are still a lot to be exploited. The widespread introduction of this technology, however, could at the same time will appear a lot of problems, it will lead to a long distances bandwidth glut and price disruptions, and set expectations for price points at the metro access/metro core that may or may not be achievable. Finally, one finds with some satisfaction the following quotes:”With so much unused fiber, when will metro nets really need WDM? What are the requirements for 40 Gbps systems? What are the new economic trade-offs between transparency and grooming. And which of the new service providers will succeed?”.

The related question for the current discussion is whether DWDM has practical application to the metro access/metropolitan environments, probably for a handful of POP-to-POP rings. If DWDM systems now in the market were redesigned to be optimized according to the requirements for metropolitan environments,  there could be increased applicability. If the systems were redesigned to meet specific price points, then their applicability would be enhanced. When the long distances industry saw major retrenchments at the turn of the decade, a number of optical vendors took the easy course of relabeling the equipment that had been developed by them for long distances applications and pasted a “metro DWDM” label onto the equipment while at the same time generating new marketing collaterals, rather than redeveloping, as would have been more appropriate equipment that is optimized and right -sized for metro access/metro core applications from both density and cost points of view. It appears that, at least for the next few years, the opportunity for metro DWDM is somewhat limited. As noted earlier, this technology may see some penetration in a metro core application of POP-to-POP rings, but extremely limited application in the metro access segment.

Systems with DWDM technology have been used extensively in the long distances space and typically cos from 100 thousands to 1000 thousands dollars or more. There are economic advantages in using DWDM when the transmission costs are high, such as in long distances applications. Such use is justified by standard transmission -versus-multiplexing cost calculations. For example, to transmit 40 Gbps over 600 km using a traditional system would require 16 separate fiber pairs with regenerators placed every 35 km for a total of 272 regenerators. A 16 DWDM wavelength channels system, on the other hand, uses a single fiber pair and four amplifiers positioned every 120 km for a total of 600 km. At the same time, new Extended Wavelength Band (EWB) fiber is being introduced that allows a wider range of operation for the transmission system; some Coarse Wavelength Division Multiplexing equipment (which is more ideal for metropolitan environment) will make use of the E-band.

Even in long distances applications, design considerations aimed at optimizing the cost profile are not always straightforward. In particular, TDW-only solutions supporting increasing speed have kept pace with a number of advantage in the WDM technology during the mid-to-late 1990s, at least for medium-size trunking application (up to 10Gbps). For example, a TDM-based solution has only one 10 Gbps SONET terminal. A WDM system that transports an aggregate capacity of 10 Gbps requires four 2.5 Gbps terminals in addition to a WDM terminal per end. Because TDM technology has typically quadrupled its capacity for a cost multiplier of 2.2, the 10 Gbps solution appears to be more cost-effective. However, if the TDM system also requires four 2.5 Gbps terminals to provide the first stage of multiplexing, the 10 Gbps solution might actually be more costly, and but we have to note that if the 2.5 Gbps terminals are already in the network, they represent a sunk cost and might not be included in the cost analysis.

Before optical line amplifiers were developed and deployed, high-speed TDM-based systems were more cost-effective than WDM because the TDM systems allowed multiple lower-speed electronic regenerators at a point in the network to be replaced with a single higher-speed regenerator at that point in the network; originally, this was not the case with the WDM design. The introduction of optical line amplifiers with the ability to amplify the entire ITU grid frequencies simultaneously allows multiple lower-speed electronic regenerators at a site to be replaced with one optical amplifier, making WDM more cost-effective.

Fiberstore designs, manufactures, and sells a broad portfolio of optical communication products, including passive optical network, or PON, subsystems, optical transceivers used in the enterprise, access, and metropolitan segments of the market, as well as other optical components, modules, and subsystems. In particular, Fiberstore products include DWDM related professional components. Welcome to visit our online store to know more about DWDM information anytime. http://www.fiberstore.com/