Tag Archive | single-mode fiber

OM5 WB MMF Vs 50 µm Laser Optimized OM4 Vs Single-Mode Fiber Cables

Network speeds like 40G and 100G Ethernet have already become the mainstream in data centers, and the industry is still working collaboratively on the next-generation development for higher density and faster speed. Multimode fibers, for example, are treated as the cost-effective solutions for short-reach optical interconnects. OM5 fiber, certificated in 2016, is know as the wide band multimode fiber (WBMMF) designed to carry signals over short wavelength (850nm to 950nm). Many enterprise IT and data center managers nowadays are adopting single-mode fiber system or OM4 cabling in the network infrastructure. Will OM5 MMF be a good alternative for 40G/100G network system? This article will provide the detailed information about OM5 fibers, and make a clear comparison between OM5, OM4 MMF and single-mode fiber cables.

OM5 fiber

Is OM5 WB MMF Fiber A Good Solution for Data Centers?

No exact answer can be provided here as OM5 MMF is still a new product in 2017.

OM5 MMF fiber has the same geometry as OM4: 50 µm of core size and 125 µm of cladding, which make it fully compatible and intermateable with OM3 and OM4 cabling. OM5 fiber specifies a wider range of wavelengths between 850 nm and 953 nm. The additional specifications of effective modal bandwidth and attenuation at 953 nm is identical to specification of OM4.

It was created to support Shortwave Wavelength Division Multiplexing (SWDM), which is one of the new technologies being developed for transmitting 40 Gb/s, 100 Gb/s, and beyond. With the use of SWDM technology, it is desirable to reduce parallel fiber count by at least a factor of four to allow continued use of just two fibers (rather than eight) for transmitting 40 Gb/s and 100 Gb/s and reduced fiber counts for higher speeds.

OM5 MMF Vs OM4

The 40/100GbE expected maximum operational distances of OM5 fiber is displayed in the above table. OM5 fiber can support longer distance of 440m for 40G SWDM, and 150m for 100G SWDM system.

How Does OM5 Differ From 50 µm Laser Optimized OM4 Fiber?

Wavelength—OM5 WB MMF is intended for operation using vertical-cavity surface-emitting laser (VCSEL) transceivers across the 846 to 953 nm wavelength range, while OM3 and OM4 50 micron laser optimized multimode fiber, whose bandwidth diminishes rapidly above the 850 nm operating wavelength.

OM5_WideBand_Multimode_Fiber_Bandwidth_Comparison

Effective Modal Bandwidth (EMB)—the best system performance is achieved by a combination of low chromatic dispersion and high EMB. OM5 EMB values are specified as following at both 850 and 953 nm.

• EMB>4700 MHz.km at 850 nm
• EMB>2470 MHz.km at 953 nm

However, the OM3/OM4 EMB values are 2000/4700 MHz·km at 850nm. We can see that the OM5 EMB is lower at 953nm compared to 850nm.

More capacity—OM5 is designed and specified to support at least four WDM channels at a minimum speed of 28Gbps per channel through the 850-953 window. Compared to OM4, it is specified only to work at the 850 nm window.

Even though signals illuminating at wavelengths greater than 850 nm will be transmitted by OM3 and OM4, the absence of specification and test data outside the 850 nm window makes it difficult to predict and model the performance of short wavelength-based WDM systems. In conclusion, OM5 is specifically designed to carry at least four channels between 850 nm and 953 nm, and guarantees that capacity increases four times.

• OM5 carries at least 4X more capacity than OM4 over a meter of fiber.
• OM5 carries 5.7X more capacity than OM3 over a meter of fiber.
• OM4 only carries 1.4X more capacity than OM3 over a meter of fiber.

Why Should I Consider OM5 Over Single-mode Fiber?

Cost-effective solution—even thought the costs of single-mode transceivers have declined considerably over the past few years, the delta relative to multimode remains approximately 50%. OM5 MMF fiber allows for more cost-effective migration to transmission speeds up to 400Gbps utilizing lower-cost optics as opposed to single-mode fiber.

Easy management & installation—in 40G/100G network, multimode connectivity together with MTP/MPO systems makes for a more user-friendly solution for data centers as well as building and campus backbones, especially in cable installation, troubleshooting, cleaning, and overall maintenance.

Seamless Migration to 400Gbps—OM5 multimode fiber delivers higher value to network owners for distances up to 500m (for data rates up to 40Gbps), and allows for smooth migration to 400Gbps for distances up to 150m. For distances beyond 500m, single-mode fiber is recommended.

Conclusion

OM5 MMF fiber has a long way to go even though it is being presented as a potential next-generation option for data centers. So far, I don’t see any tempting reasons to recommend OM5 relative to OM4 cables or single-mode fibers for 40G/100G data centers. But FS.COM will keep you upgraded with the latest development of wide band multimode fibers. For more about our 25G/40G/100G optical solutions, please directly visit our website.

The Truth About OS1 and OS2 Optical Fiber

Several years ago, OS1 fiber optic cable was the only one standard for single-mode fiber with the maximum link length for campus cabling around 10km, but 10km can no longer satisfy people’s increasing needs nowadays. Therefore, OS2 fiber that can support much longer distance than 10km has been widely utilized in telecommunication industry. But there has been some debate and confusion as to the differences between OS1 and OS2 fiber types and what the terminology actually means. Thus, the following article is provided to assist the users in understanding the differences between OS1 and OS2 fiber types. The following image shows the LC to LC fiber patch cable single mode plugging in a switch.

single-mode-fiber

OS1 and OS2 Single-mode Fibers

Firstly, OS in the term OS1 and OS2 specifications refers to the Optical Single-mode fiber. Single-mode OS1 is indoor tight buffered fiber. An OS1 cable could be a micro-core LSZH indoor cable that consists of 250 micron fibers, with the fibers being tightly enclosed in a cable with aramid strengthening yarn and a LSZH jacket. The attenuation of a OS1 fiber is higher than an OS2 fiber. From the above table, the maximum attenuation allowed per km of installed cable is 1.0 dB for OS1 for 1310nm and 1550nm, while the maximum attenuation allowed per km of installed cable is 0.4 dB for OS2 for 1310nm and 1550nm.

os1-and-os2-maximum-attenuation

Single-mode OS2 is an outdoor loose tube optical fiber cable, which is suitable for outdoor applications where the cabling process applies no stress to the optical fibers. For instance, a 250 micron coated multi-fiber, which is loose inside an enclosure or tube and/or is free to move, is classified as OS2.

OS1 or OS2 performance cables are constructed from B1.3 optical fibers (or ITU specification G.652D). Furthermore, OS1 and OS2 cable types can also include cables manufactured from B6_A fiber, which is commonly known as bend insensitive single-mode optical fiber, or ITU specification G657A2 (compatible with B1.3 optical fiber). OS1 or OS2 single mode fiber performance, does not relate to ITU specification G.655 (Non-dispersion shifted single mode optical fibers.

Why Should We Use OS2 Over OS1 Fiber?

Single-mode fiber was mainly used for long-hual applications but not marked as a cost-effective investment for future application in building. One reason is that the single-mode related products like cables and optical transceivers are offered with high price. The other is that with the price decrease of the VCSEL or laser power source, the performance gap (namely link length) between multimode or single-mode fiber is smaller everyday.

Considering this, why not use the best single-mode fiber (OS2) to create better performance and ready for high speed data networks? Besides the difference in link distance, OS1 and OS2 fibers have different attenuation—OS2 has two times less losses than OS1 fibers.  And in CWDM or DWDM network, OS1 has poor result in the wavelength range called E-band or water peak band, which makes it not suitable for the WDM-based network.

cwdm-allocation-and-fiber-loss

Figure 3: CWDM wavelength allocation and fiber loss. The solid line represents OS2 fibers. The dotted line represents the water peak.

Another good news is that if you use OS2 fiber, it will be more suitable for you to support the IEEE 802.3 multiplexed series (40G BASE-LR4 and 100G BASE-ER4). You even don’t need to change your existing OS1 fibers, as the OS2 can be mixed with OS1 in the same link. What’s more, active or passive component for OS1 like connectors, adapters also works with OS2.

Conclusion

To sum up, OS1 optical fiber is appropriate for indoor and universal tight buffered cable constructions, which are mainly deployed in internal building/campus networks, as well as internal cabling within telecommunication exchanges and data centers. While OS2 optical fiber is appropriate for outdoor and universal loose tube solutions, which would include external plant and most back-haul networks. Therefore, when deciding which single-mode optical fiber type to specify, consider the application as well as how and where the cable will be installed. For further information on optical fiber products, please contact FS.COM. Our fiber optic cable price is the cheapest with great feedback.

Choose Twisted Copper or Fiber Optic Cabling for the Data Center

When planning for a long-term cabling solution for your data center, it is important to consider future transmission speeds and the infrastructure to support them. Data center houses equipment like servers, storage units, backup power supplies and other equipment, which act as the heart of a building or campus. And all these equipment require high-bandwidth cables to connect them. The cabling in data center mainly comes in two forms—fiber or copper. To link the devices in data center, unshielded twisted pair (Cat5e/Cat6) and fiber optic fibers (MM fiber patch cords and single-mode fiber)  are commonly used. This article will focus on cabling solution for data center, and provide the cost-effective solution to you.

Twisted Copper Solutions For The Data Center

2006 witnessed the publication of the the IEEE 802.3an standard, meaning that users can use the twisted copper cabling or 10GBASE-T to support 10 Gigabit Ethernet. Compared with the former IEEE 802.3ak or 10GBASE-CX4 standard, 10GBASE-T standard has the advantage of supporting 10 Gigabit Ethernet up to 100 meters. What’s more, the 10GBASE-T using structured wiring systems based on the RJ45 connector is less costly than the 10G optical transceivers for supporting the same Gigabit Ethernet. All this attributes to the development of the copper twisted-pair cabling for horizontal, or non-backbone, distribution between LAN switches and servers.

colorful copper solution in data center

UTP (unshielded twisted pair) cabling is a widely adopted copper cabling solution due to its support for both voice and data applications. A UTP cable consists of insulated, copper wires twisted around each other to reduce crosstalk and electromagnetic induction between pairs. Typically a twisted pair will be enclosed in a shield (STP) that works as a ground; in other cases (UTP), the pair remains unshielded. UTP cables are often referred to as a Category cable, such as Cat5e, Cat6, or Cat7, etc.

Cat5e cables had been the standard solution and often used for legacy equipment or lower bandwidth needs. But Cat6 is the most common copper type in new installations today, especially for 10G Ethernet application. Cat5e will soon be going away, with available options being Cat6, Cat6a and Cat7. These options offer increased levels of performance and improved installations. All of these cable types can adequately provide you a connection. The differences between them lie in their transmission speed capabilities and costs.

Fiber Optic Solutions For The Data Center

In a data center, bandwidth distributed to servers and other devices may range from 1 Gbqs to 10 Gbqs or more depending on application and data center models. Fiber optic cabling are usually worshiped by overall users owing to numerous advantages. For instance, compared with copper cabling, fiber systems can provide up to 60 percent space savings over copper cabling, and it also have a greater bandwidth and error-free transmission over longer distances allowing network designers to take advantage of new data center architectures.

fiber optic solution

In practical terms, fiber cables are comprised of light, which reduces signal interruption, allowing for signals to be carried longer distances seamlessly. Though fiber cables are highly sought after, the cost to purchase and install has decreased throughout the years, making them a reasonable choice for companies seeking a reliable, scalable solution. The fiber optic cables can be mainly divided into two parts, that’s multimode and single-mode fibers.

The multimode fiber type can be separated into categories: OM1, OM2, OM3, OM4. Applied for short distances, multimode fibers have a high light-gathering capacity, meaning the use of lower cost, lower wavelength technologies like LED and vertical-cavity surface-emitting lasers (VCSELs) can be employed. For longer distances, single-mode OS1 and OS2 are used; single-mode fiber uses lasers to achieve higher speeds and further distances. Additionally, fiber optic cable terminated with different optical connectors (like SC fiber cable) are also widely utilized in data centers. Fiber optic cables are critical to network performance as they do more than join servers and connect switches. They are the foundation of your technology environment. Thus it is important to have the best options for your optical network.

Field-terminated vs. Pre-terminated Fiber Solutions

In commercial building installations, an optical fiber cabling link is typically assembled in the field at the job site. The cable is pulled in from a reel of bulk cable, cut to length, attached to the patch panel housing and terminated with field installable connectors on each end. The terminated ends are then loaded into adapters in rack or wall mountable housings. Finally, the complete link is tested for continuity and attenuation.

factory-preterminated

The most efficient optical infrastructure is one in which all components are pr-eterminated in the factory see in the above picture. Connectors are installed, tested and packaged in the factory. The installer unpacks the components, pulls the preconnectorized cable assembly into place, snaps in the connectors and installs the patch cords connecting to the end equipment. This is the fastest installation method and provides the best solution for turning up servers quickly and lessening the risk of not meeting the customer’s availability expectations. The design and product selection process remains the same with selection and specification of fiber type, fiber count, cable type, connector type and hardware type appropriate for the environment.

Conclusion

There is no absolute solution to utilizing fiber or copper cabling for data centers. Twisted pair cabling wins the broad acceptance among users owing to the horizontal medium, low initial cost, and the ability to deliver higher data rate LAN services and the flexibility to use one medium for all services. Therefore, in the majority of situations, copper cabling remains the preferred choice for the final link to the desktop, and other short links such as those found in data centers. However, with the speeds increasing and more copper cables installed, copper-based LANs will require more complex and expensive electronics. It might be inappropriate or impractical to implement in many current building environments.

While fiber optic cabling’s significant bandwidth distance gives it advantages over twisted pair in centralized architectures. Thanks to its high performance and high density, fiber optic cabling becomes an important factor where equipment density and heat dissipation are a concern. To sum up, whether to use copper or fiber for network cable type, the data center must have the best and fastest cabling. FS.COM offers a variety of integrated, holistic physical infrastructure solutions for data center intra-rack and inter rack applications. All the products including high speed interconnect optics, cable assemblies, cable management hardware etc. guarantee a reliable and stable performance for your network. If you have any requirement, please send your request to us.