Tag Archives: WBMMF

OM4 vs. OM5: What’s the Difference?

As the demand for bandwidth, new transmission media must be developed to meet the requirements of users. The latest in optical transmission media is called OM5 fiber. To help you use this advanced fiber to its greatest advantage, this paper describes the basis of OM5 fiber, and highlights the key differences with OM4 fiber.

What Is OM5 Fiber?

According to the ISO/IEC 11801, OM5 fiber specifies a wider range of wavelengths between 850nm and 953nm. It was created to support short wavelength division multiplexing (SWDM), which is one of the many new technologies being developed for transmitting 40Gb/s and 100Gb/s. In June 2016, ANSI/TIA-492AAAE, the new wideband multimode fiber standard, was approved for publication. And in October of 2016, OM5 fiber was announced as the official designation for cabling containing WBMMF (Wide Band Multimode Fiber) by ISO/IEC 11801. From then on, OM5 may be a potential new option for data centers that require greater link distances and higher speeds.

FS OM5-Fiber

What Is OM4 Fiber?

OM4 is laser-optimized 50um fiber having 4.7GHz*km EMB bandwidth designed for 10 Gb/s, 40 Gb/s, and 100 Gb/s transmission. OM4 fiber has been on the market since 2005, sold as premium OM3 or OM3 fiber. The OM4 cable designation standardizes the nomenclature across all manufacturers so that the customer has a clearer idea of the product that they are buying. OM4 fiber is completely backwards compatible with OM3 fiber and shares the same distinctive aqua jacket. OM4 was developed specifically for VSCEL laser transmission and allows 10 Gig/second link distances of up to 550 Meters (compared to 300M with OM3) and offers an Effective Modal Bandwidth (EMB) of 4700 MHz-km.

OM4 vs. OM5: What’s the Difference?

Since OM1 and OM2 fiber can not support 25Gbps and 40Gbps data transmission speeds, OM3 and OM4 were the main choices for multimode fiber to support 25G, 40G and 100G Ethernet. However, it’s becoming more costly for optical fiber cable to support next-generation Ethernet speed migration as bandwidth requirements increase. Against such a background, OM5 fiber was born to extend the benefits of multimode fiber in data centers.

OM4-V.S-OM5

The key difference between them is that EMB is specified only at 850 nm for OM4 fiber at 4700 MHz-km, while OM5 EMB values are specified at both 850 nm and 953 nm and the value at 850 nm is greater than that of OM4. Therefore, OM5 fiber offers users longer length distances and more choices in optical fiber. In addition, TIA has specified lime green as the official cable jacket color for OM5, while OM4 is aqua jacket. And OM4 is designed for 10Gb/s, 40Gb/s, and 100Gb/s transmission, but OM5 is designed for 40Gb/s, and 100Gb/s transmission which reduces the fiber counts for high speed transmissions.

What’s more, OM5 cable can support four SWDM channels, each carrying 25G of data to deliver 100G Ethernet using a single pair of multimode fibers. Besides, it is fully compatible with OM3 and OM4 fiber. OM5 is available globally for installations in multiple enterprise environments, from campuses to buildings to data centers. In a word, OM5 fiber is a better choice than OM4 on transmission distance, speed and cost.

Conclusion

OM5 fiber provides next-generation multimode fiber performance for today and tomorrow’s high speed applications. With its significantly higher bandwidth, it can be assured that multimode fiber will continue to provide the most cost effective solutions for short reach applications in data centers and LANs. OM5 precisely meets the demands, and it will be your preferable choice for your data centers.

WBMMF – Next Generation Duplex Multimode Fiber in the Data Center

Enterprise data center and cloud operators use multimode fiber for most of their deployments because it offers the lowest cost means of transporting high data rates for distances aligned with the needs of these environments. The connections typically run at 10G over a duplex multimode fiber pair—one transmit (Tx) fiber and one receive (Rx) fiber. Upgrading to 40G and 100G using MMF has traditionally required the use of parallel ribbons of fiber. While parallel transmission is simple and effective, continuation of this trend drives higher cost into the cabling system. However, a new generation of multimode fiber called WBMMF (wideband multimode fiber) is on the way, which can enable transmission of 40G or 100G over a single pair of fibers rather than the four or ten pairs used today. Now, let’s get close to WBMMF.

What Is Wideband Multimode Fiber?
WBMMF is a new multimode fiber type under development that will extend the ability of conventional OM4 multimode fiber to support multiple wavelengths. Unlike traditional multimode fiber, which supports transmission at the single wavelength of 850 nm, WBMMF will support traffic over a range of wavelengths from 850 to 950 nm. This capability will enable multiple lanes of traffic over the same strand of fiber to transmit 40G and 100G over a single pair of fibers and to drastically increase the capacity of parallel-fiber infrastructure, opening the door to 4-pair 400GE and terabit applications. Multimode fiber continues to provide the most cost-effective platform for high bandwidth connectivity in the data center, and with the launch of the WBMMF solution, that platform has been extended to support higher speeds with fewer fibers and at greater distances.

Wideband Multimode Fiber

What Is the Technology Behind WBMMF?
WBMMF uses short wavelength division multiplexing (SWDM) to significantly increase its transmission capacity by four times. WDM technology is well known for its use in single-mode transmission, but has only recently been adapted for use with vertical cavity surface-emitting lasers (VCSELs), which have been proven in high-speed optical communications and are widely deployed in 10G interconnection applications. SWDM multiplexes different wavelengths onto duplex MMF utilizing WDM VCSEL technology. By simultaneously transmitting four VCSELs, each operating at a slightly different wavelength, a single pair WBMMF can reliably transfer 40G (4x10G) or 100G (4x25G). The use of SWDM then enables WBMMF to maintain the cost advantage of multimode fiber systems over single-mode fiber in short links and greatly increases the total link capacity in a multimode fiber link.

SWDM WBMMF

Why Does WBMMF Make Sense?
In order to increase transmission speeds up to 10G or 25G, transceiver vendors simply increased the speed of their devices. When 40G and 100G standards were developed, transmission schemes that used parallel fibers were introduced. This increase in fiber count provided a simple solution to limitations of the technology available at the time. It was accepted in the industry and allowed multimode links to maintain a low cost advantage. However, the fiber count increase was not without issues. At some point, simply increasing the number of fibers for each new speed became unreasonable, in part because the cable management of parallel fiber solutions, combined with the increasing number of links in a data center, becomes very challenging. Please see the picture below. Usually, 40G is implemented using eight of the twelve fibers in an MPO connector. Four of these eight fibers are used to transmit while the other four are used to receive. Each Tx/Rx pair is operating at 10G. But if we use WDMMF, two fibers are enough. Each Tx/Rx pair can transmit 40G by simultaneously transmitting four different wavelengths. This enables at least a four-fold reduction in the number of fibers for a given data rate, which provides a cost-effective cabling solution for data center.

Parallel fibers vs WBMMF

Conclusion
WBMMF is born at the right moment to meet the challenges associated with escalating data rates and the ongoing need to build cost-effective infrastructure. Besides, WBMMF will support existing OM4 applications to the same link distance. Optimized to support wavelengths in the 850 nm to 950 nm range to take advantage of SWDM, WBMMF ensures not only more efficient support for future applications to useful distances, but also complete compatibility with legacy applications, making it an ideal universal medium that supports not only the applications of the present, but also those of the future.

Original article source: http://www.cables-solutions.com/wbmmf-next-generation-duplex-multimode-fiber-in-the-data-center.html