Tag Archives: MPO

Upgrade to High Data Rate Transmission With Parallel Optics

Parallel optics represent a type of optical communication technology as well as the devices on either end of the link that transmit and receive information which are also known as parallel optical transceivers. Compared with traditional optical communication, parallel optical communication employs a different cabling structure for signal transmitting aiming at high-data transmission for short reach multimode fibers that are less than 300 meters. Traditional fiber optic transceivers cannot satisfy the increasing demand for high speed transmission, like 40GbE, while parallel optics technology can be a cost effective solution for 40/100GbE transmission.

Comparison between parallel optics technology and the traditional serial optical communication would better explain what parallel optics is and the reason why it is a cost effective solution to high data rate transmission. The following of this article will offer the comparison between the two optical communication technology from two aspects: connectivity method and key components.

Connectivity Method

Literally, parallel optics and serial optics transmit signals in different ways. In traditional serial optical communication, on each end of the link, there are one transmitter and one receiver. For example, the transmitter on End A communicates to the receiver on End B, sending a single stream of data over a single optical fiber. And a separate fiber is connected between the transmitter on End B and the receiver on End A. In this way, a duplex channel is achieved by two fibers.

2-fiber duplex connection

While in parallel optical communication, duplex transmission is achieved in a different way. A signal is transmitted and received through multiple paths, thus, the parallel optical communication can support higher data rate than the traditional optical communication. This is because, the devices for parallel optic communication on either end of the link contain multiple transmitters and receivers. For instance, in 2010 IEEE 802.3ba approved the 40GBASE-SR4 physical-medium-dependent multimode parallel optical solution, which uses eight fibers to transmit four duplex channels each at 10 Gigabit Ethernet. In this case, four 10Gbps transmitters on End A communicate with four 10Gbps receivers on End B, spreading a single stream of data over four optical fibers at a total data rate of 40Gbps.

Key Components

The parallel optical communication transmitting signals over multiple fibers, which has great advantages over traditional serial optical communication. It also means that it requires different components to support its high data rate transmission.

Connector: As previously mentioned, duplex transmission in serial optical communication uses 2-fiber duplex connectors, like duplex LC connectors to link the optics with other devices, while in parallel optical communication, multi-fibers are used to reach a higher data rate. Thus, multi-fiber connectors, like 12-fiber MPO connectors are used to connect with other devices. MPO connector is one key technology support parallel optical communication. This connectivity method is showed in the following picture?(Tx stands for transmit; Rx stands for receive).

12-fiber MTP parallel connection

Optical transceiver light source: Another complementary technology for parallel transmission is the light source of parallel optics—VCSELs (Vertical Cavity Surface Emission Lasers). Comparing with the edge-emitting semiconductor lasers in the traditional optics, VCSELs have better formed optical output which enables them to couple that energy into optical fibers more efficiently. In addition, VCSELs emit from the top surface, they may be tested while they are part of a large production batch (wafer), before they are cut into individual devices, which dramatically lowers the cost of the lasers. The following chart is about the comparison between VCSELs and edge-emitting semiconductor lasers. Cheaper to manufacture, easier to test, less electrical current required, supporting higher data rate, parallel optics using VCSELs could be a better choice to reach 40/100GbE transmission compared with traditional serial optics.

VCSEL vs Edge-Emitting Laser
Feature VCSEL Edge-Emitting Laser
Power consumption 2-3 mW 20 mW
Beam quality/ease of coupling Better, round low divergence Fine, asymmetric
Speed 10 Gbps 1 Gbps
Temperature stability 0.06 nm/oC 0.25 nm/oC
Specral width 1 nm 1-2 nm
Speckle Low in an array High

 

Parallel Optics for 40/100GbE Transmission

IEEE has already included physical layer specifications and management parameters for 40Gbps and 100Gbps operation over fiber optic cable. Two popular parallel optics solutions for 40Gbps and 100Gbps over multimode fibers are introduced here. For 40G, 40GBASE-SR4 transceiver is usually used, which requires a minimum of eight OM3/OM4 fibers for a transmit and receive link (4 fibers for Tx and 4 fibers for Rx). 100GBASE-SR10 transceiver is for 100Gbps transmission, which requires a minimum of 20 OM3/OM4 fibers for a Tx/Rx link, 10 fibers are used for Tx and the other 10 are for Rx.

40BASE-SR4 and 100BASE-SR10

Conclusion

The capabilities and uses of parallel optics and MPO technology continue to evolve and take shape as higher-speed fiber optic transmission, including 40/100GbE. It is uncertain that parallel optical communication would be the trend in the future. However, many cabling and network experts have pointed out that parallel optical communication supported with MPO technology is currently a way to equip an environment well prepared for the 40/100GbE transmission.

Source:
http://www.fs.com/blog/upgrade-to-high-data-rate-transmission-with-parallel-optics.html

More bandwidth means more testing

The use of MPO cables for trunking 10-Gbps connections in the data center has steadily risen over the past 10 years. That trunking requires use of a cassette at the end of the MPO cable designed to accommodate legacy equipment connections. Now that 40-Gbps and 100-Gbps connections are coming on the market, a migration path has emerged: Remove the 10-Gbps cassette from the MPO cable and replace it with a bulkhead accommodating a 40-Gbps connection. Then it might be possible to remove that bulkhead and do a direct MPO connection for 100 Gbps at a later date.

The problem is that while this migration strategy is an efficient way to leverage the existing cabling, in comparison to 10-Gbps connections, the 40-Gbps and 100-Gbps standards call for different optical technology (parallel optics) and tighter loss parameters.

In short, each time you migrate you need to verify the links to ensure the performance delivery the organization requires.
To understand the challenges of MPO cable validation, it’s necessary to understand MPO cables and how they’re tested in the field. An MPO connection is about the size of a fingernail and contains 12 optical fibers, each less than the diameter of a human hair – and each one needs to be tested separately. That traditionally means the use of a fan-out cord to isolate each fiber, followed by tedious manual testing, tracing, and error-prone calculations.

The actual fiber test is quick enough: typically under 10 seconds per fiber once you’re in process. But you better be cruising: While one of our enterprise customers has data centers with as little as 24 MPO fiber trunks (x12 fibers each), that same customer also has a 30,000-MPO data center installation. That’s 30,000 connections with 12 fibers each, or roughly 3,120 hours in labor (and $343,200 in cost) if you had to test them all individually.

And at some point, you better have tested them. There were two primary drivers behind development of MPO fiber trunks. The first was the ever-increasing need for cabling density in the data center. Cabling blocks airflow, so the denser the cable, the better the thermal management. And, as data center bandwidth steadily climbs to 10, 40, and 100Gbps, a dense multi-fiber cable becomes the only option.

But the second, perhaps more important factor, is the difficult and highly technical nature of field termination for fiber. We’re talking curing ovens, adhesives, microscopic fibers, etc. Given that expensive and time-consuming “craft” process, modular factory-terminated MPO cables promise simplicity, lower cost, and true plug-and-play fiber connectivity.

The challenge is that pre-terminated fiber is only guaranteed “good” as it exists in the manufacturer’s factory. It must then be transported, stored, and later bent and pulled during installation in the data center. All kinds of performance uncertainties are introduced before fiber cables are deployed. Proper testing of pre-terminated cables after installation is the only way to guarantee performance in a live application. In short, investing in factory-terminated fiber trunks to save time and decrease labor costs doesn’t really offer an advantage if the testing becomes an expensive bottleneck.

Testing and determining fiber polarity is another challenge. The simple purpose of any polarity scheme is to provide a continuous connection from the link’s transmitter to the link’s receiver. For array connectors, TIA-568-C.0 defines three methods to accomplish this: Methods A, B, and C. Deployment mistakes are common because these methods require a combination of patch cords with different polarity types.

You can buy fiber optic jumpers with any connectors from FiberStore.

 

What are MPO and MTP connectors?

MPO MTP cables are offered for various applications for all networking and device needs like 100 Gig modules. They use a high-density multi-fiber connector (MPO connector and MTP connector) system built around precision molded MT ferrule. So what are MPO and MTP connectors?

What is an MT ferrule?
MT stands for Mechanical Transfer. The MT Ferrule is a multi-fiber ferrule in which fiber alignment is dependent on the eccentricity and pitch of the fiber and alignment pin holes. The alignment is dictated by the alignment pins during mating.

The critical elements for fiber alignment are:

1. The ability to hold extreme tolerances for precision during the molding process

2. The shape, tolerances and material composition of the alignment pins

What is a MPO connector?

MPO is the industry acronym for “Multi-fiber Push On.” The MPO-style connectors are most commonly defined by two different documents:

1. IEC-61754-7 is the commonly sited standard for MPO connectors internationally

2. EIA/TIA-604-5, also known as FOCIS 5, is the most common standard sited for in the US

What is a MTP connector?

The MTP connector is a high performance MPO connector with multiple engineered product enhancements to improve optical and mechanical performance when compared to generic MPO connectors. It is in complete compliance with all MPO connector standards including the EIA/TIA-604-5 FOCIS 5 and the IEC-61754-7. It is inter-matable with all generic MPO-style connectors that are compliant to these industry standards. Generic MPO connectors are limited in performance and are not able to offer the high performance levels of the US Conec MTP connector.

Is the MTP connector an MPO connector?

Yes. The MTP connector is a high performance MPO connector engineered for better mechanical and optical performance.

What makes the MTP connector superior to generic MPO connectors?

The MTP connector has features and benefits that are not available on generic MPO connectors. Some of the key distinctions include:

1. The MTP connector housing is removable. This feature allows the customer to:

A. Re-work and re-polish the MT ferrule

B. Change the gender after assembly or even in the field

C. Scan the ferrule interferometrically after assembly

2. The MTP connector offers ferrule float to improve mechanical performance. This allows two mated ferruled to maintain physical contact while under an applied load.

3. The MTP connector uses tightly held tolerance stainless steel guide pin tips with an elliptical shape. The elliptical shaped guide pin tips improves guidance and reduces guide hole wear.

4. The MTP connector has a metal pin clamp with features for centering the push spring. This feature:

A. Eliminates lost pins

B. Centers spring force

C. Eliminates fiber damage from spring

5. The MTP connector spring design maximizes ribbon clearance for twelve fiber and multifiber ribbon applications to prevent fiber damage.

6. The MTP connector is offered with four standard variations of strain relief boots to meet a wide array of applications.

A. Round, Loose Fiber Cable Constructions

B. Oval Jacketed Cable

C. Bare Ribbon Fiber

D. Short boot which reduces the footprint by 45%. Ideal for use in space limited applications.

Fiberstore supply mtp/mpo terminated fiber optic cable. mtp fiber or mpo fiber you can choose.  FiberStore offer singlemode and multimode (OM1, OM2, 10G OM3, 10G OM4)  MPO/MTP Cable. Singlemode MPO/MTP cable is primarily used for applications involving extensive distances, 10G MPO/MTP cable provide 10 gigabit data transfer speeds in high bandwidth applications and they are 5 times faster than standard 50um fiber cable. Work with both VCSEL laser and LED sources. The meanwhile, we also provide 40G/100G MPO/MTP trunk cable.