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What’s the Difference: OM3 vs OM4

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OM3 and OM4 are two common types multimode fiber used in local area networks, typically in backbone cabling between telecommunications rooms and in the data center between main networking and storage area network (SAN) switches. Both of these fiber types are considered laser-optimized 50/125 multimode fiber, meaning they both have a 50μm micron diameter core and a 125μm diameter cladding, which is a special coating that prevents light from escaping the core. Both fiber types use the same connectors, the same termination and the same transceivers—vertical-cavity surface emitting lasers (VCSELs) that emit infrared light a 850 nanometers(nm). OM3 is fully compatible with OM4. With so many similarities, and often manufactured with the same color aqua cable jacket and connectors, it can be difficult to tell these two fiber types apart. So, what’s the difference between them? Do these two types fiber refer to the same thing?

om3-vs-om4

What’s the Difference: OM3 vs OM4

In fact, the difference between om3 and om4 fiber is just in the construction of the fiber optic cable. The difference in the construction means that OM4 cable has better attenuation and can operate at higher bandwidth than OM3. What is the reason of this? For a fiber link to work, the light from the VCSEL transceiver much have enough power to reach the receiver at the other end. There are two performance values that can prevent this—optical attenuation and modal dispersion.

Attenuation is the reduction in power of the light signal as it is transmitted (dB). Attenuation is caused by losses in light through the passive components, such as cables, cable splices, and connectors. As mentioned above the connectors are the same so the difference in OM3 and OM4 performance is in the loss (dB) in the cable. OM4 fiber causes lower losses due its construction. The maximum attenuation allowed by the standards is shown below. You can see that using OM4 will give you lower losses per meter of cable. The lower losses mean that you can have longer links or have more mated connectors in the link.

Maximum attenuation allowed at 850nm: OM3 <3.5 dB/Km; OM4 <3.0 dB/Km

Light is transmitted at different modes along the fiber. Due to the imperfections in the fiber, these modes arrive as slightly different times. As this difference increases you eventually get to a point where the information being transmitted cannot be decoded. This difference between the highest and lowest modes is known as the modal dispersion. The modal dispersion determines the modal bandwidth that the fiber can operate at and this is the difference between OM3 and OM4. The lower the modal dispersion, the higher the modal bandwidth and the greater the amount of information that can be transmitted. The modal bandwidth of OM3 and OM4 is shown below. The higher bandwidth available in OM4 means a smaller modal dispersion and thus allows the cable links to be longer or allows for higher losses through more mated connectors. This gives more options when looking at network design.

Minimum Fiber Cable Bandwidth at 850nm: OM3 2000 MHz·km; OM4 4700 MHz·km

Choose OM3 or OM4?

Since the attenuation of OM4 is lower than OM3 fiber and the modal bandwidth of OM4 is higher than OM3, the transmission distance of OM4 is longer than OM3. Details are shown in the table below. According to your network scale, to choose a more suitable cable type.

Fiber Type 100BASE-FX 1000BASE-SX 10GBASE-SR 40GBASE-SR4 100GBASE-SR4
OM3 2000 Meters 550 Meters 300 Meters 100 Meters 100 Meters
OM4 2000 Meters 550 Meters 400 Meters 150 Meters 150 Meters

Since OM4 performs better than OM3 cables, usually, OM4 cable is about twice as expensive as OM3 cable. This may be a big limited factor of OM4 cables’ application. However, if you choose to shop in Fiberstore, you may get much cheaper OM4 fiber nearly the same as the OM3 fiber. Price of different types OM3 and OM4 cables in Fiberstore is listed in the table below:

Fiber Type 3m Standard LC duplex 3m Armored LC duplex 3m HD LC duplex 3m Standard MTP
OM3 US$ 3.30 US$ 7.20 US$ 22.00 US$ 49.00
OM4 US$ 4.00 US$ 8.00 US$ 24.00 US$ 54.00

Either OM3 or OM4 cable can satisfy your unique cabling needs. Just choose the most suitable one for your network to cost less and achieve more.

Related Article: Wideband Multimode Fiber (OM5): What to Expect From It?

Related Article: OM3 vs OM4 Multimode Fiber: Which Should I Choose?

What Kind of Single-mode Fiber Should You Choose?

As we all know, multimode fiber is usually divided into OM1, OM2, OM3 and OM4. Then how about single-mode fiber? In fact, the types of single-mode fiber seem much more complex than multimode fiber. There are two primary sources of specification of single mode optical fiber. One is the ITU-T G.65x series, and the other is IEC 60793-2-50 (published as BS EN 60793-2-50). Rather than refer to both ITU-T and IEC terminology, I’ll only stick to the simpler ITU-T G.65x in this article. There are 19 different single-mode optical fiber specifications defined by the ITU-T.

Name Type
ITU-T G.652 ITU-T G.652.A, ITU-T G.652.B, ITU-T G.652.C, ITU-T G.652.D
ITU-T G.653 ITU-T G.653.A, ITU-T G.653.B
ITU-T G.654 ITU-T G.654.A, ITU-T G.654.B, ITU-T G.654.C
ITU-T G.655 ITU-T G.655.A, ITU-T G.655.B, ITU-T G.655.C, ITU-T G.655.D, ITU-T G.655.E
ITU-T G.656 ITU-T G.656
ITU-T G.657 ITU-T G.657.A, ITU-T G.657.B, ITU-T G.657.C, ITU-T G.657.D

Each type has its own area of application and the evolution of these optical fiber specifications reflects the evolution of transmission system technology from the earliest installation of single-mode optical fiber through to the present day. Choosing the right one for your project can be vital in terms of performance, cost, reliability and safety. In this post, I may explain a bit more about the differences between the specifications of the G.65x series of single-mode optical fiber families. Hope to help you make the right decision.

G.652
The ITU-T G.652 fiber is also known as standard SMF (single-mode fiber) and is the most commonly deployed fiber. It comes in four variants (A, B, C, D). A and B have a water peak. C and D eliminate the water peak for full spectrum operation. The G.652.A and G.652.B fibers are designed to have a zero-dispersion wavelength near 1310 nm, therefore they are optimized for operation in the 1310-nm band. They can also operate in the 1550-nm band, but it is not optimized for this region due to the high dispersion. These optical fibers are usually used within LAN, MAN and access network systems. The more recent variants (G.652.C and G.652.D) feature a reduced water peak that allows them to be used in the wavelength region between 1310 nm and 1550 nm supporting Coarse Wavelength Division Multiplexed (CWDM) transmission.

G.652 

G.653
G.653 single-mode fiber was developed to address this conflict between best bandwidth at one wavelength and lowest loss at another. It uses a more complex structure in the core region and a very small core area, and the wavelength of zero chromatic dispersion was shifted up to 1550 nm to coincide with the lowest losses in the fiber. Therefore, G.653 fiber is also called dispersion-shifted fiber (DSF). G.653 has a reduced core size, which is optimized for long-haul single-mode transmission systems using erbium-doped fiber amplifiers (EDFA). However, its high power concentration in the fiber core may generate nonlinear effects. One of the most troublesome, four-wave mixing (FWM), occurs in a Dense Wavelength Division Multiplexed (CWDM) system with zero chromatic dispersion, causing unacceptable crosstalk and interference between channels.

G.653

G.654
The G.654 specifications entitled “characteristics of a cut-off shifted single-mode optical fiber and cable.” It uses a larger core size made from pure silica to achieve the same long-haul performance with low attenuation in the 1550-nm band. It usually also has high chromatic dispersion at 1550 nm, but is not designed to operate at 1310 nm at all. G.654 fiber can handle higher power levels between 1500 nm and 1600 nm, which is mainly designed for extended long-haul undersea applications.

G.655
G.655 is known as non-zero dispersion-shifted fiber (NZDSF). It has a small, controlled amount of chromatic dispersion in the C-band (1530-1560 nm), where amplifiers work best, and has a larger core area than G.653 fiber. NZDSF fiber overcomes problems associated with four-wave mixing and other nonlinear effects by moving the zero-dispersion wavelength outside the 1550-nm operating window. There are two types of NZDSF, known as (-D)NZDSF and (+D)NZDSF. They have respectively a negative and positive slope versus wavelength. The following picture depicts the dispersion properties of the four main single-mode fiber types. The typical chromatic dispersion of a G.652 compliant fiber is 17ps/nm/km. G.655 fibers were mainly used to support long-haul systems that use DWDM transmission.

G.655

G.656
As well as fibers that work well across a range of wavelengths, some are designed to work best at specific wavelengths. This is the G.656, which is also called Medium Dispersion Fiber (MDF). It is designed for local access and long haul fiber that performs well at 1460 nm and 1625 nm. This kind of fiber was developed to support long-haul systems that use CWDM and DWDM transmission over the specified wavelength range. And at the same time, it allows the easier deployment of CWDM in metropolitan areas, and increase the capacity of fiber in DWDM systems.

G.657
G.657 single-mode fiberG.657 optical fibers are intended to be compatible with the G.652 optical fibers but have differing bend sensitivity performance. It is designed to allow fibers to bend, without affecting performance. This is achieved through an optical trench that reflects stray light back into the core, rather than it being lost in the cladding, enabling greater bending of the fiber. As we all know, in cable TV and FTTH industries, it is hard to control bend radius in the field. G.657 is the latest standard for FTTH applications, and, along with G.652 is the most commonly used in last drop fiber networks.

From the passage above, we know that different kind of single-mode fiber has different application. Since G.657 is compatible with the G.652, some planners and installers are usually likely to come across them. In fact, G657 has a larger bend radius than G.652, which is especially suitable for FTTH applications. And due to problems of G.643 being used in WDM system, it is now rarely deployed, being superseded by G.655. G.654 is mainly used in subsea application. According to this passage, I hope you have a clear understanding of these single-mode fibers, which may help you make the right decision.

Related Article: Is G.652 Single Mode Fiber Your Right Choice?

SMF or MMF? Which Is the Right Choice for Data Center Cabling?

Selecting the right cabling plant for data center connectivity is critically important. The wrong decision could leave a data center incapable of supporting future growth, requiring an extremely costly cable plant upgrade to move to higher speeds. In the past, due to high cost of single-mode fiber (SMF), multimode fiber (MMF) has been widely and successfully deployed in data center for many years. However, as technologies have evolved, the difference in price between SMF and MMF transceivers has been largely negated. With cost no longer the dominant decision criterion, operators can make architectural decisions based on performance. Under these circumstances, should we choose SMF or MMF? This article may give you some advice.

MMF Can’t Reach the High Bandwidth-Distance Needs
MMF datacenterBased on fiber construction MMF has different classifications types that are used to determine what optical signal rates are supported over what distances. Many data center operators who deployed MMF OM1/OM2 fiber a few years ago are now realizing that the older MMF does not support higher transmit rates like 40GbE and 100GbE. As a result, some MMF users have been forced to add later-generation OM3 and OM4 fiber to support standards-based 40GbE and 100GbE interfaces. However, MMF’s physical limitations mean that as data traffic grows and interconnectivity speeds increase, the distance between connections must decrease. The only alternative in an MMF world is to deploy more fibers in parallel to support more traffic. Therefore, while MMF cabling has been widely and successfully deployed for generations, its limitations now become even more serious. Operators must weigh unexpected cabling costs against a network incapable of supporting new services.

SMF Maybe a Viable Alternative
Previously, organizations were reluctant to implement SMF inside the data center due to the cost of the pluggable optics required, especially compared to MMF. However, newer silicon technologies and manufacturing innovations are driving down the cost of SMF pluggable optics. Transceivers with Fabry-Perot edge emitting lasers (single-mode) are now comparable in price and power dissipation to VCSEL (multimode) transceivers. Besides, Where MMF cable plants introduce a capacity-reach tradeoff, SMF eliminates network bandwidth constraints. This allows operators to take advantage of higher-bit-rate interfaces and wave division multiplexing (WDM) technology to increase by three orders of magnitude the amount of traffic that the fiber plant can support over longer distances. All these factors make SMF a more viable option for high-speed deployments in data centers.

SMF datacenter

Comparison Between SMF and MMF
10GbE has become the predominant interconnectivity interface in large data centers, with 40GbE and 100GbE playing roles in some high-bandwidth applications. Put simply, the necessity for fiber cabling that supports higher bit rates over extended distances is here today. With that in mind, the most significant difference between SMF and MMF is that SMF provides a higher spectral efficiency than MMF, which means it supports more traffic over a single fiber using more channels at higher speeds. This is in stark contrast to MMF, where cabling support for higher bit rates is limited by its large core size. This effectively limits the distance higher speed signals can travel over MMF fiber. In fact, in most cases, currently deployed MMF cabling is unable to support higher speeds over the same distance as lower-speed signals.

Name Interface FP (SMF) VCSEL (MMF)
Link Budget (dB)
4 to 6 2
Reach (in meters) (Higher value is better)
10GbE 1300 300
40GbE 1300 150
100GbE 1300 <100

Conclusion
As operators consider their cabling options, the tradeoff between capacity and reach is important. Network operators must assess the extent to which they believe their data centers are going to grow. For environments where users, applications, and corresponding workload are all increasing, single mode fiber offers the best future proofing for performance and scalability. And because of fundamental changes in how transceivers are manufactured, those benefits can be attained at prices comparable to SMF’s lower performing alternative.

Source:http://www.fs.com/blog/smf-or-mmf-which-is-the-right-choice-for-data-center-cabling.html

Low-loss Connectivity For Multimode Fiber Applications

Optical insertion loss budgets are now one of the top concerns among data center managers, especially in today’s large virtualized server environments with longer-distance 40 and 100 gigabit Ethernet (GbE) backbone switch-to-switch deployments for networking and storage area networks (SANs). In fact, loss budgets need to be carefully considered during the early design stages of any data center—staying within the loss budget is essential for ensuring that optical data signals can properly transmit from one switch to another without high bit error rates and performance degradation.

low-loss-multifiber-connectivity

With the length and type of the fiber optic cable and number of connectors and splices all contributing to the link loss, data center managers are faced with the challenge of calculating each connection point and segment within their fiber channels. Multi-fiber push on (MPO) or mechanical transfer push on (MTP) connectors are rapidly becoming the norm for switch-to-switch connections due to their preterminated plug and play benefits and ease of scalability from 10 to 40 and 100 gigabit speeds. Unfortunately, typical MPO MTP module insertion loss may not allow for having more than two mated connections in a fiber channel, which significantly limits design flexibility and data center management. Low loss, rather than standard loss, MPO/MTP connectors better support multiple mated connections for flexibility over a wide range of distances and configurations while remaining within the loss budget.

MTP LC

Typical MPO/MTP connectors, which are required for 40 and 100 GbE eployments have insertion loss values that range from 0.3 dB to 0.5 dB. Typical LC multimode fiber connectors have loss values that range from 0.3 dB to 0.5 dB. While better than the allowed 0.75 dB TIA value, typical connector loss still limits how many connections can be deployed in 10, 40 and 100 GbE channels. For example, with an LC connector loss of 0.5 dB, a 300-meter 10 GbE channel over OM3 fiber can include only three connectors with no headroom. Having just two or three connections prevents the use of cross connects at both interconnection (MDA) and access switches (HDA).

Due to improvements in connector technology and manufacturing techniques, Fiberstore has succeeded in lowering the loss to 0.20 dB for MTP connectors and to 0.15 dB (0.1 dB typical) for LC and SC connectors, well below the industry standard of 0.75 dB and loss values offered by other manufacturers.

For 10 GbE, Fiberstore low loss LC fiber jumpers offer a loss of 0.15 dB (typical 0.1 dB) and Fiberstore low loss plug and play MTP to LC or SC modules offer a loss of 0.35 dB (typical 0.25 dB). For 40 and 100 GbE, MTP to MTP pass-through adapter plates and MTP fiber jumpers offer a loss of 0.2 dB. These lower loss values allow data center managers to deploy more connection points in fiber channels, enabling the use of distribution points or cross connects that significantly increase flexible configuration options.

Table 2 below provides an example of how many connections can be deployed in 10, 40 and 100 GbE channels over OM3 and OM4 multimode fiber using low loss MTP to LC modules for 10 GbE and low loss MTP to MTP pass-through adapters for 40 and 100 GbE versus standard loss solutions.

As indicated in Table 2, the use of low loss connectivity allows for four connections in a 10 GbE OM3 or OM4 channel compared to just two when using standard loss connectivity. Low loss connectivity allows for eight connections in a 100- meter 40/100 GbE channel over OM3 versus just four connections using standard loss, and five connections in a 150-meter 40/100 GbE channel over OM4 fiber compared to just two connections using standard loss. Deploying cross connects between interconnection and access switches requires a minimum of four connections, depending on the configuration. Therefore, cross connects in a full-distance optical channel are simply not feasible without low loss connectivity.

Figures 6, 7 and 8 shows some example scenarios for deploying cross connects in 10 GbE and 40/100 GbE channels over OM3 and OM4 fiber using Fiberstore low loss fiber connectivity. In Figure 6, all changes are made at the cross connect with LC fiber jumpers. The switches remain separate and the permanent MTP trunk fiber cables need only be installed once. The cross connect can be placed anywhere within the channel to maximize ease of deployment and manageability.

MTP Trunk Cable

Figure 7. shows an OM3 40/100 GbE channel with six Fiberstore low loss MTP-MTP pass-through adapter plates and low loss trunks. This scenario offers 0.4 dB of headroom and provides even better manageability and security. All changes are made at the cross connects via MTP fiber jumpers, switches remain separate, and the MTP trunk cables need only be installed once.Once again, the cross connects can be located anywhere in the data center for maximum flexibility. This allows for one-time deployment of high fiber-count cabling from the cross connect at the interconnection switch to the cross connect at the access switch. Adding additional access switches can be accomplished with short fiber runs from the cross connect.

Figure 7: For maximum flexibility, manageability and security, up to eight low loss MTP-MTP pass-through adapters can be deployed using low loss trunks in a 100-meter 40/100 GbE switch-to-switch backbone channel over OM3 fiber.

If the loss budget does not permit deploying six MTP to MTP adapters, one option is to deploy MTP to LC or MTP to MTP jumpers from the cross connect to the equipment, depending on the equipment interface. For example, if using OM4 fiber to extend the channel distance to 150 meters, up to five Low Loss MTP-MTP pass through adapters can be deployed as shown in Figure 8.

OM3 Multimode 10G Aqua Fiber Optic Cables

The Internet, telephone calls, and cable television all transmit information that can pass through fiber optic cables. Imagine having all this information at lightning-fast speed with less signal disturbances. The mechanics that lie beneath the ingenious work of fiber optic cables rests simply with the fact that light travels faster than electricity with fewer disturbances. The end result? Fiber optic cables provide a quicker and clearer transmission of data. Designed for optimal performance, our fiber optic cables allow you to enjoy the best quality technological experiences possible.

Now, many fibre optic cable suppliers provide a full range of bulk fiber optic cable. Including om3 fiber optic cable, om4 multimode fiber, armored fiber cable, simplex fiber optic cable, multimode duplex fiber optic cable and so on. Today, I will recommended the OM3 fiber optic cable in this blog. Know more OM3 fiber optic cable info and how to choose it.

OM3 10G fiber optic cables are used for 10Gigabit Ethernet applications. These cables are also called multimode OM3 10G Aqua fiber optic cables. Our OM3 10G cables come in various types including different connector types, cable structure and cable length. Our OM3 multimode fiber that are compliant to ISO/IEC 11801 standards. These cables are used for 10Gbps networks to meet the requirement of continuous growing of high data rates.

Big quantity information is generated every day on the internet and people need to exchange more and more information which in turn result in the demand of more and more bandwidth. IEEE802.3ae defined the 10Gigabit Ethernet standards used in LANs. OM3 10G multimode fiber optic cables are developed for such 10Gig Ethernet applications, they are with so called OM3 optical fiber, which is 50/125 type and with industrial acknowledged Aqua color. In FiberStore, we supply the OM3 cable standard color is aqua, but we also supply the customized color service,such as black, blue, orange, green, brown, slate, white, red, yellow, purple, rose, aqua or custom specified. We provide many types of OM3 products, including various kinds of OM3 fiber cable assemblies with various connectors like SC, ST , FC, LC, MTRJ, etc.

OTHER INFO: Which optical fiber should I choose, 50 micron or 62.5 micron?

Although 62.5 micron fiber was the most popular only a few years ago, 50 micron quickly gained market share and is continuing to do so. 50 micron fiber can have up to 20 times the bandwidth (data throughput capacity) of 62.5 micron. For identification purposes, multimode fiber, and also singlemode fiber, is often referred to by its performance level identified by ISO/IEC (International Organization of Standards and International Electrotechnical Committee), which is based on the fibers bandwidth capabilities. 62.5 micron multimode is referred to as OM1. 50 micron fiber is referred to as OM2, OM3 and the recently added OM4. As you would imagine, OM4 has greater bandwidth than OM3 and OM3 has greater bandwidth than OM2.

Fifty micron OM3 fiber is designed to accommodate 10 Gigabit Ethernet up to 300 meters, and OM4 can accommodate it up to 550 meters. Therefore, many users are now choosing OM3 and OM4 over the other glass types. In fact, nearly 80% of 50 micron fiber sold is OM3 or OM4.

If you require higher data rates or plan on upgrading your network in the near future, laser optimized 50 micron (OM3 or OM4) would be the logical choice.

We also supply 10Gig multimode fiber optic cables with various optional structures, such as om3 multimode fiber, om4 multimode fiber, multimode duplex fiber optic cable and so on. Our  fiber optic cables are manufactured according to industrial standards and they feature the good price and reliable quality. Per foot price of each fiber cable is flexible depending on the quantities of your order, making your cost of large order unexpected lower. Customers can also have the flexibility to custom the cable plant to best fit their needs. Only fiber cable that meets or exceeds industry standards is used to ensure quality products with best-in-class performance.FiberStore is a your best buy fiber optic cable place.