How to choose the MPO system for your Fiber Infrastructure

Nowadays, the demand for high connection speeds is increasing at an intimidating pace. People need to send -and receive- more data than ever, and the technology that’s available to them often seems to just not being able to keep up.
Optical fiber seems to represent the best choice when it comes to offering higher speeds -currently required by data center networks. In contrast to multimode and single mode optical networks, which were typically based on duplex fiber links, parallel fiber (MPO-based) connectivity has now become the ideal go-to choice, since it allows the use of pre-terminated systems that can be used in a quick and efficient way.
Nonetheless, this type of connectivity had been used to deliver duplex connectivity combined with duplex modules and breakouts. The selection of multifiber interfaces responds to the demands of increasing applications and density.
This turnover has led to a general consideration of using duplex connectivity, but at the same time, it needs to fill the necessity of including a combination of parallel and duplex interfaces.
Apart from considering these new iterations, it is essential to have a solid grasp on the evolution of network equipment and on the advantages of implementing an infrastructure based on duplex connections.
That being said, let us walk you through the Ethernet Roadmap.
There are several applications housed in data centers, which implies that those applications will demand a diversity in the connectivity topologies. It is commonly known that most networks use duplex links, but the demand for higher speeds requires using duplex links into other groups of links, which is when the term of parallel links enter the debate.
Likewise, this new incorporation asks for certain cabling structures that can handle this new array of options while having the acute vision of what the new results from this structures may provide us with. In other words, what we’re now witnessing it’s a migration from arrangements that involve duplex links into parallel link options that need to cover the requirements of higher speeds.
The great thing about parallel links is that they reduce the operation costs at a significant rate. Since they offer higher connectivity densities, it reduces the power consumption to send that data. This type of connection multiplies the information been transported, so it offers a notable reduction in the time employed in the transmission of information.
The increase of speeds has also developed a certain progress when it comes to the outlining of separate transmission lanes. In the end, the throughput will be augmented due to the incorporation of additional fiber, or the multiplexing over just a single a fiber.
Each one of these parameters will determine the selection of the fiber media and the options for cabling that will become the most appropriate for your data center. The decision of moving from single and duplex links to parallel ones will surely affect your cabling choice. This may traduce to a significant cost at the beginning, but it shall be seen as an investment in the long term.
The first thing you need to do is to determine the desired capacity that your data center will possess in the short-term future. Your team can come in handy forecasting this scenario since it is very well equipped with considering, evaluating and even trying several technologies, platforms and routing strategies.
After coming to terms to answering each one of the specific requirements demanded by your new system, the pre-terminated MPO-based fiber cabling system will enable a quicker utilisation and a certain flexibility of configuration, along with a cabling topology that corresponds appropriately with the new direction and desired performance of your data center direction.
Multimode fiber is definitely the primary media choice for the enterprise data center. Each one of the diverse types of multimode fiber (MMF) will affect the scale and scope of the data center that can be supported when speeds increase, so you need to take that into consideration.
Aside from combining “lanes” to provide for higher and better link speeds, multiplexing several wavelengths on a single pair of fibers offers great results.
The great thing about this new structure of links is that it offers a new set of applications. Depending on the type of configuration, migrations can be enabled between duplex and parallel optics.
This quality is very eloquent when it comes to supporting the notion of the flexibility offered by parallel links. If new needs come up, you should be able to accommodate those necessities by making adjustments to your new structure in your data center.
Every decision that you make towards implementing parallel links will affect your structure -and space- of your cabling, so every single analysis that you can make before adding something to your new structure should be mandatory.
To put it mildly, you need to be aware of the physical space every new configuration is going to occupy. You can have lots of great ideas for new connections, but if you can’t afford the space for it, none of them will work out. But don’t worry, you just need to gain conscience of the dimensions of your cabling configurations so you can design them and implement them properly.
The good thing about duplex cables is that they are very flexible, so not all of these considerations should be thought of as limitations. You can work around them -and, trust us, you should!
By merely thinking about all of this, you could be concerned about the cost it implies, and we hear you. Notwithstanding, this is a cost you need to assume. Not only because the current situation demands it, but also because this decision will stand out as an investment for the near future.
New designs imply adjustments so you can incorporate duplex and parallel connections, meaning that perhaps new racks or more space for your cabling will be needed. This inclusion will also call for changes in the management of your team, which will have to face new ways to handle these devices.
Human beings tend to reject at first all sorts of changes, it’s in our nature, but if you are totally convinced on the benefits that each and single one of these procedures will bring to your data center in the future, you will work through them focused on having the vision aiming at an impending success. The current concerns need to be replaced with a relentless optimism that your work will be enhanced in the long run.
We hope you find this article very useful and that this information can help you increase the speed -and hopefully the quality- of your data center.
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Do you know Fiber Optical Transponders?

As we know, transponder is important in optical fiber communications, it is the element that sends and receives the optical signal from a fiber. A transponder is typically characterized by its data and the maximum distance the signal can travel.
Functions of a Fiber Optical Transponder includes:
Electrical and optical signals conversion
Serialzation and deserialization
Control and monitoring
Applications of Fiber Optical Transponder
Multi-rate, bidirectional fiber transponders convert short-reach 10gb/s and 40 gb/s optical signals to long-reach, single-mode dense wavelength division multiplexing (DWDM) optical interfaces.
The modules can be used to enable DWDM applications such as fiber relief, wavelength services, and Metro optical DWDM access overtay on existing optical infrastructure.
Supporting dense wavelength multiplexing schemes, fiber optic transponders can expand the useable bandwidth of a single optical fiber to over 300 Gb/s.
Transponders also provide a standard line interface for multiple protocols through replaceable 10G small form-factor pluggable (XFP) client-side optics.
The data rate and typical protocols transported include synchronous optical network/synchronous digital hierarchy (SONET/SDH) (OC-192 SR1), Gigabit Ethernet (10GBaseS and 10GBaseL), 10G Fibre Channel (10 GFC) and SONET G.709 forward error correction (FEC)(10.709 Gb/s).
Fiber optic transponder modules can also support 3R operation (reshape, retime, regenerate) at supported rates.
Often, fiber optic transponders are used to for testing interoperability and compatibility. Typical tests and measurements include litter performance, receiver sensitivity as a function of bit error rate (BER), and transmission performance based on path penalty.Some fiber optic transponders are also used to perform transmitter eye measurements.
fiber-mart.com Provides Optical Transponders Solution
Let’s image that the architecture that can not support automated reconfigureability. Connectivity is provided via a manual Fibre Optic Patch Panel, a patch panel where equipment within an office is connected via fiber cables to one side (typically in the back), and where short patch cables are used on the other side (typically in the front) to manually interconnect the equipment as desired.  There is a point that Fibre Optic Patch Panel, people usually different ports patch panel , for example, 6, 8, 12, 24 port fiber patch panel and they according to different connectors to choose different patch panel, such as LC patch panel,  LC patch panel,  MTP patch panel…
optical network
The traffic that is being added to or dropped from the optical layer at this node is termed add/drop traffic, the traffic that is transmitting the mode is called through traffic. Regardless of the traffic type, note that all of the traffic entering and exiting the node is processed by a WDM transponder. In the course of converting between a WDM-compatible optical signal and a client optical signal, the transponder processes the signal in the electrical domain. Thus, all traffic enters the node in the optical domain, is converted to the electrical domain, and is returned to the optical domain. This architecture, where all traffic undergoes optical electrical (OEO) conversion, is referred to as the OEO architecture.

Differences between EPON and GPON

PON is the abbreviation of passive optical network, which only uses fiber and passive components like fiber splitter and combiner. EPON (Ethernet PON) and GPON (Gigabit PON) are the most important versions of passive optical networks, widely used for Internet access, voice over Internet protocol (VoIP), and digital TV delivery in metropolitan areas. Today we are going to talk about the differences between EPON and GPON.
Technology Comparison of EPON and GPON
EPON is based on the Ethernet standard 802.3 that can support the speed of 1.25 Gbit/s in both the downstream and upstream directions. It is well-known as the solution for the “first mile” optical access network. While GPON, based on Gigabit technology, is designated as ITU-T G.983 which can provide for 622 Mbit/s downstream and 155 Mbit/s upstream. GPON is an important approach to enable full service access network. Its requirements were set force by the Full Service Access Network (FASN) group, which was later adopted by ITU-T as the G.984.x standards–an addition to ITU-T recommendation, G.983, which details broadband PON (BPON).
As the parts of PON, they have something in common. For example, they both can be accepted as international standards, cover the same network topology methods and FTTx applications, and use WDM (wavelength-division multiplexing) with the same optical frequencies as each other with a third party wavelength; and provide triple-play, Internet Protocol TV (IPTV) and cable TV (CATV) video services.
Costs Comparison
No matter in a GPON or in an EPON, the optical line terminal (OLT), optical network unit (ONU) and optical distribution network (ODN) are the indispensable parts, which are the decisive factor of the costs of GPON and EPON deployments.
The cost of OLT and ONT is influenced by the ASIC (application specific integrated circuit) and optic module. Recently, the chipsets of GPON are mostly based on FPGA (field-programmable gate array), which is more expensive than the EPON MAC layer ASIC. On the other hand, the optic module’s price of GPON is also higher than EPON’s. When GPON reaches deployment stage, the estimated cost of a GPON OLT is 1.5 to 2 times higher than an EPON OLT, and the estimated cost of a GPON ONT will be 1.2 to 1.5 times higher than an EPON ONT.
We all know that the ODN is made up of fiber cable, cabinet, optical splitter, connector, and etc. In the case of transmitting signals to the same number of users, the cost of EPON and GPON would be the same.
Summary
Nowadays, since many experts have different opinions on EPON and GPON. Thus, there is no absolute answer to determine which is better. But one thing is clear: PON, which possesses the low cost of passive components, has made great strides driven by the growing demand for faster Internet service and more video. Also, fiber deployments will continue expanding at the expense of copper, as consumer demands for “triple-play” (video, voice and data) grow.

Functions of ONT and OLT in GPON Network

Gigabit passive optical network (GPON) is a point-to-multipoint access mechanism providing end users with the ability to consolidate multiple services onto a single fiber transport network. To realize this technology, many devices are used to support the network, such as optical splitter, ONT, OLT, etc. In this article, we will mainly discuss the functions of ONT and OLT in GPON network.
Functions of ONT and OLT
Optical network terminal (ONT) is an optical modem that connects to the termination point with an optical cable. It is used at end user’s premise to connect to the PON network on one side and interface with the user on the other side. Data received from the customer end is sent, aggregated and optimized by the ONT to the upstream OLT. ONT is also known as optical network unit (ONU). ONT is an ITU-T term, while ONU is an IEEE term. They both refer to the user side equipment in GPON network. A small difference between them might be the application locations. ONU can work in different temperature and weather conditions.
Optical line terminal (OLT) is the endpoint hardware equipment located in a central office of the PON network. Its basic function is to control the float information in optical distribution network (ODN) to go in both directions. OLT converts the standard signals used by fiber optic service (FiOS) to the frequency and framing used by PON system. In addition, it coordinates the multiplexing between the ONT conversion devices. There are two float directions for OLT system. One is the upstream direction to distribute different types of data and voice traffic from users. The other is the downstream direction which gets data, voice and video traffic from metro network or from a long-haul network and sends it to all ONT modules on the ODN.
How to Add or Delete ONT on OLT?
Way to Add ONT on OLT
If the password of an ONT is obtained, you can run the ONT add command to add the ONT offline. However, if the password is unknown, you can run the port portid ont-auto-find command in the GPON mode to enable the ONT auto-find function of the GPON port, and then run the ONT confirm command to confirm the ONT. When the ONT is added, you need to run the display ONT info command to see the current status of ONT. If the control flag is active,
Way to Delete ONT on OLT
When you need to delete the ONT on OLT, please use the delete command. Then ONT configuration data is deleted with the deletion of the ONT and the online ONT is forced offline. ONT can’t be deleted when it has been configured with other services. You need to unbind the service first before delete the ONT.
How to Troubleshoot ONT?
To troubleshoot the ONT, you should remember that the most important step is to connect your computer directly to the ONT to see if the problem goes away. You can use the Ethernet cable for connection. If the problem still exists, you can reconnect the ONT power supply to clear its internal cache. If the network can not be restored after the above methods, maybe you need to consult professionals for help.

Media Converters Provide Cost-effective Soluton

Network complexity, demanding applications, and also the growing number of devices around the network are driving network speeds and bandwidth requirements higher and forcing longer distance requirements within the LANs. However, Media Converters provide solutions to these complaints, utilizing the optical fiber if it is needed, and integrating new equipment into existing cabling infrastructure.
What is the Media Converter? Media converter can be a device that functions like a transceiver, converting the electrical signal found in copper UTP network cabling into light waves used in fiber optic cabling. It gives you seamless integration of copper and fiber, and other fiber types in Enterprise LAN networks. Media converter supports numerous protocols, data rates and media types.
Fiber optic connectivity is important when the distance between two network devices exceeds the transmission distance of copper cabling. Copper-to-fiber conversion using media converters enables two network devices with copper ports to become connected over extended distances via fiber optic cabling. Media converters provide fiber-to-fiber conversion from multimode fiber to single-mode fiber or single-mode fiber to multimode fiber, and convert a dual fiber link to single fiber using Bi-directional (BIDI) data flow. They can also convert between wavelengths for WDM applications with devices such as WDM multiplexer. Media converters are typically protocol specific and are available to guide a wide variety of network types information rates.
For example, the Fiber-To-Fiber Media Converter can offer connectivity between multimode and single-mode fiber, between different power fiber sources and between dual fiber and single-fiber. It extends a multimode network across single-mode fiber with distances as much as 140km. Within this application, two Gigabit Ethernet switches equipped with multimode fiber ports are connected by using a couple of Gigabit Fiber-To-Fiber Media Converters, which convert the multimode fiber to single-mode and let the cross country connection between the switches. Furthermore, they support conversion from one wavelength to a new with all the single mode to multimode converter or multimode to singlemode media converter. These media converters are usually protocol independent and designed for Ethernet,and TDM applications.
Media converters do a lot more than convert copper-to-fiber and convert between different fiber types. Media converters for Ethernet networks can support integrated switch technology, and offer the opportunity to perform 10/100M and 10/100/1000M rate switching. Additionally, media converters can support advanced bridge features, including VLAN, QoS prioritization, Port Access Control and Bandwidth Control – that facilitate the deployment of recent data, voice and video to get rid of users. Media converters can offer all these sophisticated switch capabilities in a, cost-effective device.
Media converters save CAPEX by enabling interconnection between existing switches, servers, routers and hubs; preserving the investment in legacy equipment. They reduce CAPEX by avoiding the necessity to install new fiber links by enabling WDM technology through wavelength conversion. Media converters also reduce network OPEX by helping troubleshoot and remotely configure network equipment that is at distant locations, not waste time and funds when there is not just a network administrator on the distant location.
Media converters are necessary to produce a more reliable and cost-effective network nowadays. So, where are we able to get high quality Media Converters with reasonable price? Visit Fiber Media Converter Solution in fiber-mart.com now.

CWDM System Testing Process

With the explosion of CWDM, it is very necessary to formulate a basic testing procedure to certifying and troubleshooting CWDM networks during installation and maintenance. Today, one of the most commonly available test methods is the use of an OTDR or power source and meter, which is capable of testing the most commonly wavelengths, 1310, 1490, 1550 and 1625nm.
This article here is based on the pre-connectorized plug and play CWDM systems that allow for connecting to test equipment in the field:
In the multiplexing module of a pre-connectorized CWDM system, wavelengths are added to the network through the filters and transmitted through the common port. The transmitted wavelengths enter the COM port in the de-multiplexing module and are dropped. All other wavelengths present at the MUX/DeMux module are went through the express port.
Most of today’s OTDRs have expanded capability for testing wavelengths in addition to 1310 and 1550 nm. The OTDR allows partial testing of such system offered in test equipment source. The OTDR allows partial testing of these systems by using the flexibility of pre-connectorized solutions. This is done by switching connections within the CWDM field terminal to allow for testing portions of the non-1310/1550 nm optical paths.
To test the 1310nm, the first step is to test the downstream portion of a system at 1310 nm by connecting the OTDR to the 1310 nm input on the CWDM MUX located at the headend. Then switch the test leads over the the upstream side and repeat. Test method is the same for both the downstream and upstream paths.
1550 nm testing is performed similarly by switching the test leads to the 1550nm ports. If additional wavelengths are present, you need to follow the procedures below:
Using the 1550 nm test wavelength, switch the OTDR connection to the 1550 nm input port on the headend MUX. Have a technician stationed at the field terminal connect the drop cable leg connectors for the 1570 nm customer to the 1550 nm port on the Mux/demux device. What should be noted is that in a play and plug solution this should not require repositioning where the drop cable passes through the OSP terminal. Test the downstream 1570 nm passive link at 1550 nm, and then repeat for the 1570 nm upstream side. When testing is complete, have the technician switch the connections for the 1570 nm drop back to the 1570 nm ports on the field MUX/DeMUX device as shown in Figure 6. Repeat this process for the 1590 nm, 1610 nm drop cables and other wavelengths present. Finally, test the 1550 nm path normally with the 1550 nm drop cable connected to the 1550nm MUX/DeMUX ports.
Since the OTDRs is able to test at 1490 or 1625 nm, the drop cables under test could be connected to the EXP port of the module and tested at 1490 or 1625 nm respective wavelength, without having to connect each to the 1550 nm port. Otherwise the procedure is the same.
As CWDM network become more and more common the data they carrying has also become critical. The procedure introduced here allows for testing modular pre-connectorized CWDM systems with standard optical test equipments. Relative channel power can be measured with a wide-band fiber optic power meter at the filter outputs or at other points in the network with the aid of a wavelength selective test device or with an optical spectrum analyzer.

MEMS Based Variable Optical Attenuators

by http://www.fiber-mart.com

It is commonly known that fiber optic attenuators are used in fiber optic communications, as fiber optic tester tools to test power level margins by temporarily adding a calibrated amount of signal loss, or installed permanently to properly match transmitter and receiver levels. According to its stability, it divided into fixed fiber optic attenuators and variable optical attenuators. Variable fiber optic attenuators generally use a variable neutral density filter, with advantages of being stable, wavelength insensitive, mode insensitive, it offers a large dynamic range.
With the rapid increases in traffic on optical telecommunications systems, there is an active program for developing transmission devices for use in wavelength division multiplexing (WDM), which is becoming mainstream technology for providing higher transmission speeds and a larger number of signal channels. It has been suggested that in the WDM systems of the future, variation in power due to the wavelength could be reduced a the quality of transmission improved by adjusting the power after demultiplexing into individual signals wavelengths. It is envisaged that the current method, in which the power of all the multiplexed optical signals is adjusted by a single variable optical attenuators (VOA) would give way to a method in which one VOA is used for each wavelength. Given the number of multiplexed wavelengths, this change will require VOAs that are considerably more compact. Against this background, There have developed a VOA using micro-electromechanical system (MEMS) technology with loss characteristics that have low wavelength dependence.
Single-mode fiber was used as the input and output of the VOA developed here, with a graded index fiber having the same diameter, 125um, as the SMF fusion spliced for a specified length, to form an optical coupling with a lens function. An anti-reflection coating is applied to the tip of the GIF (graded index fiber). GIF tip is polished at an angle so that the light beam emitted from the end of the GIF is not aligned with the optical axis of the fiber, but is at an angle to it. This angled optical beam is interrupted by means of a shutter that has been formed by inductively-coupled plasma deep reactive ion etching. The MEMS chip uses a silicon-on-insulator wafer, with the shutter, actuator and fiber grooves formed simultaneously on the chip by ICP-DRIE, followed by metal vapor deposition over the whole chip.
The actuator of the MEMS chip is of the comb type, and the GIF is held in the fiber grooves by means of adhesive. The MEMS chip with this GIF optical coupling system is fixed by adhesive within a casing, which is hermetically sealed.
MEMS variable optical attenuators are variable in three different configurations. The VA series works in transmission, whereas the VP series uses reflection to modulate the attenuation. The VX series is the VP or the VA series in mint plastic packing. In terms of performance, the VP series achieves lower insertion loss and better Polarization dependent loss characteristics. Whereas the VA series allows for an easier array integration and is the lower cost.
FiberStore offers a full line of optical attenuator variable testers, they are often combined with an active system component to maintain optical power on a network even if the power changes in the input signals. Our automatical variable optical attenuators are specifically designed for use in DWDM networks with individual channel source elements such as add/drop transmitters. The cost and performance characteristics of our automatically variable optical attenuators are specifically targeted to allow for the use of these devices in volume as principal DWDM channel stabilization components.