Data center needs to be upgraded to 100G / 200G / 400G in the future. Data center users must face many types of optical modules such as IEEE, MSA, or private products. We cannot foresee whether the parallel transmission or duplex transmission will be used in the future As an important network infrastructure in the data center, cabling must have openness, scalability and flexibility to support different network applications in the future.
OM5 multimode fiber is compatible with both traditional parallel transmission optical modules and optical modules that support duplex transmission, and OM5 fiber can greatly reduce the number of fiber cores and increase the transmission distance. Therefore, from the perspective of overall investment cost, investment return and risk control in the data center It can be seen that OM5 fiber is the preferred transmission medium for optical communications in new data centers.
Multimode fiber classification
Since the popularization of Ethernet in the 1990s, multi-mode fiber has been widely used in short-distance application scenarios including commercial buildings and data centers. Multi-mode fiber has developed from the first generation of OM1 to today's fifth generation of OM5 . The traditional OM1 to OM4 multimode fiber technology evolution is mainly along the longitudinal development of bandwidth (including LED overflow emission bandwidth OFL and LD effective mode bandwidth EMB), with some disruptive Ethernet technologies such as duplex + dual wavelength BiDi and The emergence of SWDM4 technology for short wavelength division multiplexing urgently needs a new type of multimode optical fiber that can support a wider wavelength range between 850-950nm, and OM5 optical fiber came into being. In order to support the emerging SWDM4 short wavelength division multiplexing and BiDi duplex dual wavelength applications, TIA and ISO / IEC released the technical standards of TIA-492 AAAE and IEC60793-2-10 A1a.4b OM5 broadband multimode fiber in 2017, respectively .
OM5 fiber has higher transmission capacity
OM5 extends the wavelength range supported by OM3 and OM4 fibers in the lateral direction. If we regard multimode fiber as a highway, the traditional OM1, OM2, OM3, OM4 multimode fiber has only one channel, while OM5 has four channels, and the transmission capacity is increased by four times.
OM5 fiber supports the latest BiDi and SWDM technologies
From a historical perspective, traditional OM1 multimode fiber is designed for 100M Ethernet, OM2 multimode fiber is designed for 1G Ethernet, OM3 multimode fiber is mainly designed for 10G Ethernet, and OM4 multimode fiber is mainly designed for parallel transmission. 100GBase-SR4 Ethernet design, OM4 multimode fiber optimizes the differential mode delay (DMD) of OM3 multimode fiber during high-speed transmission, so the transmission distance has been greatly improved.
OM5 multimode fiber supports more wavelength channels, so it is more beneficial for using four-wavelength SWDM4 or dual-wavelength BiDi technology. OM5 fiber is fully compatible with traditional 40GBase-SR4 and 100G Base-SR4 optical modules. It can support different applications in the data center in the future.
OM5 fiber
Use less fiber to support higher speed applications
As the data center network speed increases, the number of fiber cores required is also increasing. Traditional OM3 and OM4 optical fibers mainly work at 850nm wavelength. OM5 optical fiber can support 4 wavelengths between 850-950nm, so OM5 optical fiber transmission 40/100 / 200G Ethernet only requires two core fibers, and OM5 optical fiber supports 400G in the future. Ethernet, for higher-speed 400G Ethernet applications, such as 400G Base-SR 4.2 (4 pairs of fiber 2 wavelengths, each channel uses 50G PAM4) or 400G Base-SR4.4 ((4 pairs of fiber 4 wavelengths, each Each channel uses 25GNRZ), requiring only 8-core OM5 fiber. Compared with the first generation 400G Ethernet 400G Base-SR16 (16 pairs of fibers, each channel transmits 25Gbps), the number of optical fibers required is only four times that of traditional Ethernet one.
OM5 fiber supports longer transmission distance
For 40G SWDM4 optical module, OM3 fiber transmission distance is 240 meters, OM4 fiber transmission distance is 350 meters, OM5 fiber transmission distance is 440 meters; for 100G SWDM4 optical module, OM3 fiber transmission distance is 75 meters, OM4 fiber The transmission distance is 100 meters, and the OM5 fiber transmission distance is 150 meters. For the 100G eSWDM4 optical module to be released by Finisar, the transmission distance of OM5 fiber is 400 meters. For the 40GBiDi module, OM3 fiber transmission distance is 100 meters, OM4 fiber transmission distance is 150 meters, OM5 fiber transmission distance is 200 meters; for 100GBiDi module, OM3 fiber transmission distance is 70 meters, OM4 fiber transmission distance is 100 meters, OM5 fiber transmission distance is 150 meters.
Because the optical module and the optical fiber have sufficient margin, the actual transmission distance is much higher than the transmission distance given by IEEE international standards or MSA multi-vendor agreement. CommScope, Finisar and ExFO demonstrated the 100G SWDM4 optical module of Finisar on the 417-meter CommScope OM5 fiber link with zero error rate transmission at a domestic financial industry summit this year. The test simulates the most demanding six network connection scenarios. The 417-meter fiber link contains six MPO / LC fiber boxes. ExFo test instruments test indicators include important indicators such as bit error rate, jitter, and delay. The test shows all The indicators are within the specified range.
OM5 fiber loss is lower
ISO and TIA released the latest cabling standards ISO 11801 3rd and TIA / EIA.0-D in 2017, respectively. The new standard removes traditional OM1, OM2 multimode optical cables and adds OM5 broadband multimode optical cables. ISO reduces the attenuation of OM5 optical cable from 3.5 dB / Km of the previous OM3 and OM4 optical cable to 3.0 dB / km, and additionally increases the bandwidth requirement at the wavelength of 953 nm. The third working group of ISO / IEC JTC1 SC25 WG3 is drafting a wiring guideline specification for transmission of high-speed network applications on multimode fiber. This specification compares OM3, OM4, 10/40/100/200 / 400G duplex and parallel network applications. The transmission distance of OM5 multimode fiber is recommended for newly built data centers.
OM5 Multimode Fiber Ecosystem
As the physical transmission medium for data communication, optical fiber provides support for network equipment. The promotion of OM5 fiber is inseparable from the support of network equipment manufacturers. At present, there are two technologies for transmitting high-speed networks with a small number of optical fibers in the market: BiDi and SWDM4. The equipment manufacturers currently providing BiDi include FIT, Cisco, H3C, BroadCade, etc .; SWDM4 forms a strong multi-vendor alliance including Finisar, Lumentum, Dell EMC , H3C, Arista, Huawei, Hisense, etc. From the perspective of the Ethernet ecological chain, OM5 multimode fiber and BiDi and SWDM4 equipment manufacturers have formed a complete and extensive ecosystem. With the increase in the shipment of these 40 / 100G network equipment and the massive deployment of OM5 fiber, The ecosystem is gradually maturing.
OM5 multimode fiber test
OM5 multimode fiber testing is exactly the same as the traditional OM3, OM4 multimode fiber testing equipment and test procedures, users do not need to purchase additional test equipment.
