Category Archives: Fiber Optical Transceivers

Introduction to Compatible Transceiver Module

Compatible transceiver modules are highly favored by designers because of ease of use and affordability. Features like the monitor photo detector (MPD) for eye safety and the high-speed GaAs PIN photodiode are often presented in compatible modules. But many customers don’t trust OEM or alternative party compatible transceiver module. Even thought we have talked with them several times about our 3-party compatible modules for Cisco and other famous brand like Juniper, HP, extreme. Here I’d like to dig into some features of compatibility transceiver modules. Therefore customers will hold an objective attitude about the topic after going through the whole text.

Two Factors Concerning Compatible Transceiver Modules
Compatibility depends on two factors. Take compatible SFP transceiver module as an example, does a SFP need DDM function? DDM is short for Digital-diagnostic-monitoring that provides user with critical information concerning the status of transmitted and received signals. Obviously a SFP with DDM is better than one without a DDM. All you have to do is to figure out whether you need that function or not. Then make the right selection.

Does the host equipment check the ID code and lock out alternative party components? Certainly most Cisco core equipment and routers do lock out all but Cisco ID SFP modules. We do not hear any news about what Cisco equipment does and does not lock out third-party SFP.

How Does Compatible Transceiver Module Work?
Each module is unique and holds its own information in EEPROM; this memory is coded with specified identifiers such as part numbers and manufacturers details. When the device is installed, the host device then checks the memory for the correct information to confirm compatibility. A hot-pluggable device is always ready to work immediately after installation. It requires no time to program or no installation woes to figure out. That’s why most designers prefer to use compatible transceiver module.

Main Features of Optical Transceivers
Transceivers are hot pluggable so that they can easily take the place of the original transceiver without powering down the whole equipment. For example, a Finisar FTLF1323P1BTR transceiver may be compatible with the original Finisar SFP transceiver. This device, typically, have built-in diagnostic features, and duplex LC connector interface. This particular device will reach a transmission length of 15km and operates at a wavelength of 1310nm. The following image shows an outlook of FTLF1323P1BTR.

compatible transceiver module

In general, most transceiver modules will connect with the existing electrical circuitry of the module. The transceiver module may use optical or copper network cords to accomplish this goal. Media converters, Ethernet switching, routing equipment, and distance extenders may all be featured along with transceivers. The best part about compatible transceivers is that they can be easily removed and replaced in the host device.

However, many customers may encounter a situation—why my compatible transceiver module does not work with the host devices. This is a common problem, a large amount of host devices do not have a firmware check for compatibility, this is known as an “open platform”. Many compatible transceiver modules are sold as compatible when in fact they are open platform, they will work in many host devices but not in any that require coded transceivers. OEM SFP transceivers are coded specifically to suit each host device to avoid this problem. Even Finisar’s range of FTLF1217P2BTL and FTLF1323P1BTR SFPs are covered.

Summary
Keep in mind that the compatibility has nothing to do with the functions of the transceiver, only in recognizing ID code and selecting to lock out third-party transceiver or not. FS.COM offers a full range of compatible transceiver modules. Till now, we did not get any negative feedback from our customers for our compatibility transceivers. Every designer should choose the devices that work best for them in order to maximize the use of the devices in their designs.

Basic Information About Fiber Optic Transceiver

Optical fiber transceivers are also called fiber optic transmitter and receiver, which are used to send and receive optical information in a variety of different applications. The role of the optical module is photoelectric conversion. These optical modules are scalable and flexible in their use, and this is why they are preferred by designers. Here is what you need to know about the basics of fiber optic transceivers.

Fiber Optic Transmitters and Receivers
Fiber optic transmission system consists of a transmitter on one end of a fiber and a receiver on the other end. The transmitter end takes in and converts the electrical signal into light, after the optical fiber transmission in the fiber cable plant, the receiver end again converts the light signal into electrical signal. Both the receiver and the transmitter ends have their own circuitry and can handle transmissions in both directions. Fiber optic cables can both send and receive information. The cables can be made of different fibers, and the information can be transmitted at different times. The following picture shows a fiber optic datalink.

fiber optic datalink

Sources of Fiber Optic Transceiver
There are four types of fiber transmitters used to convert electrical signals into optical signals. These sources of fiber optic transmitters include: distributed feedback (DFB) lasers, fabry-perot (FP) lasers, LEDs, and vertical cavity surface-emitting lasers (VCSELs). They are all semiconductor chips. Take QSFP-40G-UNIV as an example, it is Arista QSFP-40G-UNIV compatible 40G QSFP+ transceiver. It uses DFB lasers as sources for fiber optic transmitters, which are used in long distance and DWDM systems. DFB lasers have the narrowest spectral width which minimizes chromatic dispersion on the longest links.

Arista QSFP-40G-UNIV

The choice of the devices is determined mainly by speed and fiber compatibility issues. As many premises systems using multi-mode fiber have exceeded bit rates of 1 Gb/s, lasers (mostly VCSELs) have replaced LEDs. Fiber optic transceivers are reliable, but they may malfunction or become out-dated. If an upgrade is necessary, there are hot-swappable fiber optic transceivers. These devices make it easy to replace or repair without powering down the device.

How Fiber Optic Transceiver Works?
Information is sent in the form of pulses of the light in the fiber optics. The light pulses have to be converted into electrical ones in order to be utilized by an electronic device. Thanks to the conversion by fiber optic transceivers: In its fiber optic data links, the transmitter converts an electrical signal into an optical signal, which is coupled with a connector and transmitted through a fiber optic cable. The light from the end of the cable is coupled to a receiver, where a detector converts the light back into an electrical signal. Either a light emitting diode (LED) or a laser diode is used as the light source.

Packaging
Optical fiber transceivers are usually packaged in industry standard packages like SFP, SFP+, XFP, X2, Xenpak, GBIC. According to the fiber type it connects to, there are MM (multi-mode), SM (Single-mode), as well as WDM fiber (CWDM, DWDM modules). The SFP modules support up to 4.25 Gbps with a connector on the optical end and a standard electrical interface on the other end. The QSFP are for 40 Gigabit networks using a LC duplex connection. Take compatible Brocade 40G-QSFP-LR4 as an example, it supports link lengths of 10km on single-mode fiber cable at a wavelength of 1310nm.

Summary
Keep in mind that fiber optic transceiver has two ends. One has an optical cable plug and another for connecting an electrical device. Each aspect of the transceivers is necessary to properly deliver a signal to its destination. Be aware of all aspects of fiber optic transceivers to purchase what you need for your application. Fiberstore supplies a wide variety of 40GBASE QSFP+ transceiver modules for you to choose from. More detailed, please contact us directly.

The 40G QSFP transceiver Comparison

Data center regularly went through great migration from 1G, 10G to 40G, 100G over the past few decade. Since IEEE 802.3ba standard defined the 40G Ethernet on June 17, 2010. The newest widely adopted optical transceivers is the QSFP+ that offers aggregated optical speeds of 40G. There are many variants for QSFP+ small from factor including LR4 (10km single-mode), IR4 (2km single-mode) or ESR4 and SR4 for short haul multi-mode. So what are they and what is the difference between them? The following passage will provide a satisfying answer to you.

QSFP optical transceivers have four separate 10G channels to simultaneously operating for supplying 40GbE network and sum up the capacity into a single channel. The following tables shows QSFP40G portfolio, of which 40GBASE-SR4, 40GBASE-LR4 and 40GBASE-ER4 are the most commonly used 40G physical layers.

40GBASE

  • 40GBASE-SR4

40GBASE-SR4 (short range) is a port type for multi-mode fiber and uses 850nm lasers. It uses four lanes of multi-mode fiber delivering serialized data at a rate of 10.3125 Gbit/s per lane. 40GBASE-SR4 has a reach of 100m on OM3 and 150m on OM4. There is a longer range variant 40GBASE-ESR4 with a reach of 300m on OM3 and 400m on OM4. This extended reach is equivalent to the reach of 10GBASE-SR. Take JG325A (see in Figure 2) as an example, it is HP compatible 40GBASE-SR4 QSFP+ transceiver. It primarily enables high-bandwidth 40G optical links terminated with MPO multi-fiber connectors and can also be used in a 4x10G module for interoperability with 10GBASE-SR interfaces.

HP JG325A

  • 40GBASE-ER4

40GBASE-ER4 (extended range) is a port type for single-mode fiber being defined in P802.3bm and uses 1300nm lasers. It uses four wavelengths delivering serialized data at a rate of 10.3125 Gbit/s per wavelength.

  • 40GBASE-LR4

40GBASE-LR4 (long range) is a port type for single-mode fiber and uses 1300nm lasers. It uses four wavelengths delivering serialized data at a rate of 10.3125 Gbit/s per wavelength. Take FTL4C1QE1C as an example, it is Finisar FTL4C1QE1C  (see in Figure 3) compatible 40GBASE-LR4 QSFP+ transceiver supporting link lengths of 10km at a wavelength of 1310nm.

Finisar FTL4C1QE1C

Comparison of These Three 40GBASE Standards
Through the above definitions of each type of 40G physical layers, you may have a further understanding of them. Now, we are comparing them one by one. 40GBASE-SR4 is for multi-mode fiber while 40GBASE-LR4 and 40GBASE-ER4 is a port type for single-mode fiber. The multi-mode solutions require special MPO fiber ribbons (multi-strand optical cables) to transport the 4 different 10G optical connections. Single-mode solutions use only two strands of fiber and combine the 4 channels using inexpensive CWDM technology. This gives a tremendous advantage, simplifying the connectivity to standard LC optical connectors and thus reducing costs further.

In addition, 40GBASE-LR4 QSFP+ transceivers are most commonly deployed between data-center or IXP sites with single mode fiber. 40GBASE-SR4 QSFP+ transceivers are used in data centers to interconnect two Ethernet switches with 12 lane ribbon OM3/OM4 cables. And from the above figure, we can know that they support different transmission distance in different wavelengths and with different connectors.

Summary
To sum up, 40GBASE-SR4, 40GBASE-LR4 and 40GBASE-ER4 are distinguished with each other in several different features—wavelength, connector, transmission distance, etc. Fiberstore offers a wide variety of high-density and low-power 40GBASE QSFP+ transceiver modules. They are the best-selling products of our company for its large stocks, competitive price and high quality. In addition, there are also a promotion for MTP cables. For more information, please contact us directly.

Reference:
http://www.ieee802.org/3/100GNGOPTX/public/mar12/plenary/cole_01b_0312_NG100GOPTX.pdf

40 Gigabit Ethernet Solution

40 Gigabit Ethernet is a standard that enables the transfer of Ethernet frames at speeds of up to 40 gigabits per second (Gbps), allowing 40 Gigabit Ethernet-enabled equipment to handle traffic at the aggregation and core layers. It satisfies the greater demands for faster data transmission and higher bandwidths. Thus, the business case for 40 Gigabit Ethernet is becoming inescapably compelling although 10 Gigabit Ethernet is still making its way into data center. A right and cost-effective solution for 40 Gigabit Ethernet is very necessary for all users who want to migrate to 40G.

40 Gigabit Ethernet Solution

The picture above is the summary about 40 Gigabit Ethernet, explaining significantly that cables and transceivers are the basis of the whole solution. And actually, they are also the main cost of the item. Next some types of 40 Gigabit Ethernet cables and 40g qsfp transceiver will be introduced in details.

40 Gigabit Ethernet Cables

The cable applied in 40 Gigabit Ethernet can be optical fiber or copper cable. The copper cable for 40 Gigabit Ethernet is designed for short reach, up to at least 7 m. As to optical cable, there are two types: singlemode cable and multimode cable. The transmission distance of multimode cable for 40 Gigabit Ethernet can be up to 150 m, which is much shorter than the transmission distance of singlemode cable (It can be up to 10 km). Generally, the common used types are OM3 and OM4 multimode cables in that its reach supports a wider range of deployment configurations compared to copper solutions, and the cost is lower compared to singlemode solutions.

What is more, the MPO cable (Multi-Fiber Push On)/MTP (Multi-fiber Termination Push-on) cable is considered the best solution for 40GbE. It can connect the multimode transceivers to support the multifiber parallel optics channels. For 40 Gigabit Ethernet, we can use 8 fibers MPO/MTP harness cables or 12 fibers MPO/MTP trunk cables. The former is to directly connect a QSFP port to other 4 SFP+ ports. The latter is to directly connect one QSFP port to another QSFP port. Here is a picture to help you know it clearly.

MTP Cable

40G QSFP Transceiver

According to different standard form factors, 40g qsfp transceivers can be divided into different types, such as CFP transceiver, CXP transceiver and QSFP transceiver, ect.

CFP transceiver, which has 12 transmit and 12 receive 10-Gbps lanes, can support one 100 Gigabit Ethernet port, or up to three 40 Gigabit Ethernet ports. This module is used for 40GBASE-SR4, 40GBASE-LR4. The former is based on 850nm technology and supports transmission over at least 100m OM3 parallel fibers and at least 150m OM4 parallel fibers, while the latter is based on 1310nm , coarse wave division multiplexing (CWDM) technology and supports transmission over at least 10km on singlemode fiber.

CXP transceiver also has 12 transmit and 12 receive 10-Gbps lanes as well as CFP transceiver, supporting one 100 Gigabit Ethernet port or up to three 40G qsfp ports. Compared with CFP transceiver, the size of it is much smaller. And it is mainly designed for the high-density requirements of the data center, serving the needs of multimode optics and copper.

QSFP transceiver provides four transmit and four receive lanes to support 40 Gigabit Ethernet applications for multimode fiber and copper today. The size of it is the same with CXP transceiver. It is mainly designed to support Serial Attached SCSI, 40G Ethernet, PCIe, 20G/40G Infiniband, and other communications standards.

Fiberstore 40 Gigabit Ethernet Solution

Fiberstore can offer customers 40 Gigabit Ethernet connectivity options for data center networking, enterprise core aggregation, and service provider transport applications. Since the products are all in good quality and low price, it may be the best choice for you to deploy the network.

Introduction to SFP+ Direct Attach Cable

As the technology of virtualization advanced further, more bandwidth and increased data transmission are needed to accommodate the ever-growing number of operating systems and applications residing on individual servers in Data Center today. As a result, a cost-effective method to provide more bandwidth is urgently needed for Date Center. SFP+ direct attach cable as one of the high-speed data transmission solution for data center interconnection is now widely used for 10GbE. This post is going to give an introduction to SFP+ DAC.

What Is SFP+ Direct Attach Cable?

As the name implies, SFP+ direct attach cable uses the inexpensive copper twinaxial cable with SFP+ connectors on both sides, which is also based on SFP+ MSA (multi-source agreement), providing 10 Gigabit Ethernet connectivity between devices with SFP+ interfaces. In brief, it integrates SFP+ compatible connectors with a cable into a low-latency, energy-efficient, and low-cost solution. DAC is available in several lengths up to 10 meters and are currently the best cabling option for short 10 Gigabit Ethernet connections.

Types of SFP+ Direct Attach Cable

Generally, there are three types of 10G SFP+ direct attach cable: 10G SFP+ passive copper twinax cable (PCC), 10G SFP+ active copper twinax cable (ACC), and 10G SFP+ active optical cable (AOC). They are suitable for highly cost-effective networking connectivity within a rack and adjacent racks.

10G SFP+ Passive Copper Cable – SFP+ passive DAC cable offers a direct electrical connection between corresponding cable ends. It is an ideal choice for up to 12 meters. However, because of the problems of bulkiness, weight and signal integrity, it is often limited within seven and ten meters.

10G SFP+ Active Copper Cable – SFP+ active DAC cable provides signal processing electronics to avoid signal issue, thus to improve signal quality. And it can transmit data over a longer distance than SFP+ passive copper cable, which can extend to 15 to 20 meters.

10G SFP+ Active Optical Cable – Nowadays the Active Optical Cable (AOC) is accelerating data connectivity for storage, networking, and HPC (High Performance Computing) applications. It leverages fiber optic technology for the transmission of data while reducing the weight, density and power consumption of traditional copper solutions.

10GBASE SFP+ Direct Attach Cable

More Advantages Than 10GBASE-T

Currently, 10GBASE-T is not supported for OneConnect adapters due to power requirements and high latency of 10GBASE-T PHY chips. When compared with it, SFP+ direct attach cable has more advantages which is introduced below.

SFP+ Technology Ensures Optimal Performance and Lowest Latency – New dynamics within data centers mandate that the cable infrastructure handles latency sensitive applications anywhere. When comparing 10GBase-T technology with the alternative SFP+ technology, it is evident that SFP+ is the right technology to ensure optimal performance with lowest latency in the data center.

SFP+ technology lowers the power budget – SFP+ technology delivers far lower power usage than the 10GBase-T technology. The cost saving becomes obvious when deploying from 1000 to 10,000 cables in the data center.

FS.COM SFP+ Direct Attach Cable Solution

FS.COM offers high-speed direct attach solution for data center interconnection, especially the SFP+ direct attach cables for 10GbE with features such as optimizing power consumption and supporting modularity and scalability. Recently, FS.COM offers greatly discounts for Direct Attach Cable, which will save you a lot of money. And each kind of SFP+ Direct Attach Cables is full in stock so that you can make bulk orders. Of course, the more you buy, the more discounts you will get. For more information, Please contact us directly over e-mail sales@fs.com.

A Cost-effiective Solution – Cisco Compatible SFP

According to the report of Gartner, Cisco has taken up almost half of the global network equipment market share (totally $38 billion), ahead of other competitors in the telecommunication industry. To a large extend, it is the switches’ market share that attributes to this success. Cisco SFP is the small form factor pluggable module that is usually plugged into the switch. But its price is very high, even up to thousands of dollars. The highly cost is the reason why many customers hesitate to buy it. So in this case, in order to offer a cost-effective solution for you, Cisco compatible SFP in Fiberstore comes around.

Why Choose Fiberstore

Cisco compatible SFP offered by Fiberstore are the most cost-effective standards-based SFP modules fully compatible with Cisco switches & routers. The main advantage of Cisco compatible SFP over Cisco SFP is its cost, which makes it become the cost-effective solution. Here we are going to give a price comparison by taking some examples.

Model Number Price of Cisco compatible SFP Price of Cisco SFP
GLC-T $16.00 $ 395.00
GLC-LH-SMD $7.00 $ 995.00
GLC-LH-SM $7.00 $ 995.00
GLC-SX-MM $6.00 $ 500.00

With this great advantage, Fiberstore has become one of the best-sellers in this industry. What is more, besides the above kinds, various kinds of Cisco Compatible SFPs with good quality and service are also offered here.

Features & Applications of Fiberstore Cisco Compatible SFP

The capacity of Fiberstore Cisco compatible SFP modules is as good as Cisco SFP. They are both of low-power consumption, operating on Cisco switches steady. Generally, there are three kinds of Cisco compatible SFP modules designed to used for three main applications. They are Fast Ethernet SFP, Cisco Gigabit Ethernet SFP and WDM SFP. Next, each application will be given a brief description.

Fast Ethernet SFP – Fast Ethernet SFP comes in six configurations which can be described as the Cisco 100BASE-X SFP. It is a hot-swappable input/output device that plugs into Fast Ethernet ports, dual-rate Fast/Gigabit Ethernet ports, or Gigabit Ethernet ports of a Cisco switch or router, linking the port with the fiber cabling network. One of its configuration is 100BASE-FX SFP, operating on ordinary multimode fiber optic (MMF) link spans up to 2 kilometers long. But there is a point you should note that Cisco offers two products for 100BASE-FX. One is GLC-FE-100FX is for 100Mbps Ethernet ports, and the other one is GLC-GE-100FX is for Gigabit Ethernet ports. Both products can be found in Fiberstore with compatible solution.

100BASE-FX SFP

Gigabit Ethernet SFP – SFP for Gigabit Ethernet can be described as Cisco 1000BASE-X SFP, which plugs into a Gigabit Ethernet port or slot. Compared with Fast Ethernet SFP, its speed and capacity are better. And currently, it still plays an important part in the telecommunication networks. For example, 1000BASE-SX SFP, which is a cost effective module with high performance, can support dual data-rate of 1.25 Gbps/1.0625 Gbps and 550m transmission distance with MMF.

1000BASE-SX SFP

CWDM & DWDM SFP – The speed of CWDM & DWDM SFP can be up to 10 Gbps, with a full options of wavelength for both CWDM and DWDM applications. They both allow enterprises, companies and service providers to provide scalable and easy-to-deploy Gigabit Ethernet and Fibre Channel services in their networks.

Nowadays, Fiberstore has become one of the leaders in compatible optical transceiver modules global manufacturer and supplier trade. At present, there are a lot of discounts for bulk orders in Fiberstore. For more information, please contact us directly over e-mail sales@fs.com.

The application of DWDM integration systems in MSPP

Traditionally, SONET platforms have been dedicated to services that could be encapsulated within SONET frames. Today vendors not only can deliver SONET services from MSPPs, but they also can hand off these services in a DWDM wavelength service.

DWDM can be implemented with an MSPP in two ways. Most often when you think about DWDM systems. However, the multiplexing of multiple light source is always a “passive” activity. Wavelength conversion and amplification is always the “active” DWDM activity.

MSPP chassis with integrated DWDM optics in which the optics cards (in this case, OC-48s) use one of the ITU wavelengths and interfaces to an external filter. This filter multiplexes the wavelengths from various optics cards within multiple chasses and transports them over the fiber, where they are demultiplexed on the MSPP because the filter is a separate device.

This inefficient use of the rack and shelf space has led to the development of active DWDM from the MSPP. With active DWDM, the transponding of the ITU wavelength to a standard 1550-nm wavelength is performed by converting the MSPP shelf into various components required in a DWDM system. This conversion has greatly increased the density of wavelengths within a given footprint. For example the kind of passive DWDM, only 16 wavelengths could be configured within a bay, 4 per chassis. With today’s multiport, multiport optical cards, this density can be doubled to 8 wavelengths per shelf and 32 per rack.

With the integrated active DWDM solution, one MSPP chassis can be converted into a 32-channel multiplexer/demultiplexer using reconfigurable optical add/drop multiplexer (ROADM) technology. Other chassis can be converted into a multiplexer (OADM), which can receive and distribute multiple wavelengths per shelf. The implication of this is that up to 32 wavelengths can be terminated within a bay or rack, a factor of eight times the density of even early MSPPs using a passive external filter. The traffic from within each wavelength dropped into an MSPP shelf from the ROADM hub shelf can be groomed or extracted from the wavelengths carrying it, as needed, and dropped out of the OADM shelves. ROADM is an option that can be deployed in place of fixed-wavelength OADMs. Cisco Systems ROADM technology, for example, consists of two modules: 32-channel reconfigurable multiplexer (two-slot module), 32-channel reconfigurable demultiplexer (one-slot module). Use of software-provisionable, small form-factor pluggable(SFP)client connectors, and wavelength tunability for reduced card inventory requirements. Multilever service monitoring: SONET/SDH, G.709 digital wrapper, and optical service channel for unparalleled service reliability.

MSPP chassis

With so many advantages, one of the disadvantages is that parading shift is required to move the market toward MSPP-based DWDM. This slow migration is keeping vendors at bay in terms of development as they try to balance investment in the future with today’s revenue. The widespread introduction of this technology, however, DWDM price also should be considered. The price of DWDM transceivers is typically four to five times more expensive than that of their CWDM counterparts. The higher DWDM transceiver costs are attributed to a number of factors related to the lasers.

Several ways exist for protecting an MSPP-based DWDM system in the event of a fiber cut or signal degradation. Such protection options include client protection, Y-cable protection, and wavelength splitting.

Reliability for these options varies, depending on the client network architectures and service-level agreements (SLA) provided to the client. Thus, there is no “one size fits all” approach to protection.

Related websites: http://www.fs.com

Discussion of DWDM Technology Development Oppotunity

We all have a knowledge of fiber CWDM multiplexer. 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 10gbase DWDM, 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. dense wavelength division multiplexing equipment, 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.

How to Achieve Long Distance Transmission by Fiber Optic Transceiver

Recently we met a big project that involved the network channel installation about digital optical transmission equipment, in fact, it is not so complex as the organization network ways, just we can use with SDH and downward access with switches over backbone line, but because of?the SDH equipment covers all the site in the progress of construction, so it need to be solved for long distance network connections by another way. Fortunately, we have much experiences in using fiber optic transceiver, this page we will introduce the application of fiber optic transceiver in the network construction progress which combines with this experience.

1. Multimode fiber optic transceiver and multimode fiber optic cables

Fiber optic transceiver is an ethernet transmission device that can exchange the light signal and electrical signal, fiber optic cables that can transfer data over network can be divided into multimode fiber optic cables and single-mode fiber optic cables, fiber core diameter of multimode fiber cable is 50~62.5 μm,and the single-mode fiber cable core diameter is 8.3 μm. In fact, these data are not intuitive for us, we can judge it only by colors, the multimode fiber pigtail‘s color is orange and the single-mode fiber cable is yellow. From the network applications, because of multimode fiber optic cable can transmit for not tool long distance, it just can be used between the buildings, but because of the price is relatively cheap, so there are still some people like to use it.

2. Single-mode fiber optic transceiver series

With the development of technology, this phenomenon that?single mode fiber cables applied into the long distance network installation is more and more popular, nowadays many customers use fiber optic transceiver directly, just we call it FTTH (fiber to the home), and ?these different types of fiber optic transceivers we will introduce to you all based on single mode fiber cables.

Dual Fiber Single Network Port

The dual fiber single network port fiber optic transceiver just use two fibers, a fiber is used to receive and another is used to transmit. A group of fiber optic transceivers can achieve the exchange of electrical signal and light signal. The network device may a switch, also may a server, well, we can see the fiber optic transceiver as PC, which connected with the switch is straight through cable, and with the server is cross cable.?With the development of technology, the fiber optic transceiver ports have been generally made adaptive mode (automatic matching cross-line and direct line), it also bring conveniences to the projects.

Single Fiber Single Network Port

With the continuous development of business, we are faced with an unavoidable problem that the shortage of fiber resources. Some companies want to connect the network but there is only a fiber, it is time to use the single mode fiber optic transceiver, it means that receive and transmit signal over a fiber, this product use WDM technology, related product: passive cwdm mux?(shown as the figure). The wavelength usually are 1310nm and 1550 nm, and the 1310 nm stands for transmission, and the 1550 nm stands for receiving.

cwdm

Single Fiber Dual Ethernet Port

With the development of business, some units put forward higher requirements, for example, we organized network for one bank, he asked us to provide two Ethernet lines to separate from. it needs mature and safe fiber optic transceiver device technology, in order to?simply the cost of fiber optic devices and achieve the networks over one fiber, we try our best to save the fiber sources. Our solution is that using 10/100 m adaptive port devices, access into the Ethernet link which can reach 60 km,?also keep it to support network management functions.

3. Gigabit fiber optic transceivers and integrated optical interface switches

The advantages of using fiber optic transceiver to connect the network, not only stable, but also it has fast speed, 100M full duplex and even 1000M duplex. For example, there is a Engineering machinery manufacturing enterprise, they use the 100M link to network at the beginning, but due to the requirements of the developments of business, we need to provide higher speed to them, fortunately, the progress of the technology provide good products for us, just gigabit fiber cable, from the appearances of fiber cable, it has no differences with 100M fiber transceivers. Yeah, the fiber optic transceiver we used can be directly plugged into the original power supply unit box, which just needs to change the fiber optic transceiver and then upgrade the bandwidth from Fast to Ethernet. Otherwise, we found that the education industry prefer to use an integrated gigabit fiber interface on the switches.

Cisco GLC-SX-MM/GLC LH SM Transceiver Compatible 1000BASE-SX SFP Transceiver Module

SFP (Small Form-Factor Pluggable Plus) fiber transceiver modules make the fiber optic network or fiber-Ethernet network easier to upgrade or maintain, users can replace a single SFP module during the process instead of replace the whole board with many modules on it. SFP transceiver are different types working with different wavelength for various kinds of distances. SX SFP use 850nm for max 550 meters, LX SFP use 1310nm for max 10km, ZX SFP could reach 80km. There is also copper SFP that use a RJ45 interface. DOM function for SFP is optional, it help users detect real time SFP working status SFP transceiver is an innovative, next-generation transceiver module.

Cisco SFP Modules is also hot plugable, it is an upgraded version fiber optic transceiver, it represents the trend to be smaller and more flexibility. Cisco Compatible SFP includes a wide range of the transceivers with different working wavelength and distance. In the following list I will introduce you some information about GLC SX MM Transceiver and GLC LH SM Transceiver.

GLC SX MM Transceiver

Cisco GLC-SX-MM is 1000Base-SX SFP fiber optic transceiver for multimode fiber and it works at 850nm wavelength. GLC SX MM SFP is hot swappable module that fit for Gigabit Ethernet port or slot and link the port with the network, whose interface is dual LC for optical. GLC SX MM is about 1.3 cm x 5.7 cm x 0.9 cm in dimension, and 75g in weight. The GLC SX MM transceivers are compatible with SFP Multi-Source Agreement (MSA), 1000Base SX standard for Gigabit Ethernet and SFF-8472.

The GLC SX MM transceiver consists of three sections: a VCSEL laser transmitter, a PIN photodiode integrated with a trans-impedance preamplifier (TIA) and MCU control unit. All modules satisfy class I laser safety requirements. The GLC SX MM SFP transceivers are high performance, cost effective modules supporting data-rate of 1.25Gbps and 550m transmission distance with MMF.

GLC LH SM Transceiver

Cisco GLC-lH-SM SFP fiber optic transceiver working at 1300nm wavelength, GLC LH SM is suit for both multimode optical fiber and single mode optical fiber, it is small size transceiver with LC interface and it is hot swappable, easy to use, no need further configuration. GLC LH SM is used in Gigabit network and its max working distance is 10km over SMF or 550meters over MMF, data transfer rate at 1Gbps and it works based on IEEE 802.3z standards.
The GLC LH SM transceiver consists of three sections: a FP laser transmitter, a PIN photodiode integrated with a trans-impedance preamplifier (TIA) and MCU control unit. All modules satisfy class I laser safety requirements.
SFP fiber optic transceivers are upgraded version of its former GBIC transceivers, Cisco SFP transceiver adopt LC interface and its size is only about half of GBIC, thus Cisco SFP fiber transceivers fit for dense installations.