Issue link: https://www.e-digitaleditions.com/i/1284149
48 I ICT TODAY FIGURE 1: Shipments of 100 GbE by reach, 2010-2023. Source: LightCounting Ethernet Forecast - September 2018. 100 GbE by Reach - Shipments 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 100-300 m 500 m 2 km 10-20 km 40 km Figure 1 shows LightCounting's prediction for strong 100 GbE growth from 2018-2023 for both MMF-based 100 to 300 m reach and SMF-based 2 km reach solutions. Both MMF and SMF solutions are expected to grow significantly. The predicted uptake of 100 GbE MMF modules, driven by the introduction of 100 Gb/s switch links and later by the development of 100 Gb/s servers, shows the need for 400 GbE MMF modules. New Ethernet standards are being developed to support this demand. 400GBASE-SR16, an MMF-based 16-fiber pair solution for 400 Gb/s applications has been standardized but is not expected to ship in large volumes. Two new 400 Gb/s multimode solutions were standardized in January 2020. In 2018, the IEEE P802.3cm 400 Gb/s over Multimode Fiber Task Force was created, tasked with developing standards for 400GBASE-SR4.2 and 400GBASE-SR8. These solutions are based on 50 Gb/s lanes on OM3, OM4, and OM5. Furthermore, 400GBASE-SR4.2 is the first multi- mode Ethernet standard that utilizes WDM and takes advantage of OM5 fiber's wideband capability. In this solution, two wavelengths or lanes are used to transmit 100 Gb/s over each fiber pair. Four MMF pairs used with two wavelengths/fiber leads to the new designa- tion 400GBASE-SR4.2 where 400GBASE defines the 400 Gb speed, SR denotes Short Reach, and the 4.2 describes the number of fiber pairs, followed by the number of wavelengths used. These modules have been introduced in the market and are expected to be widely deployed in enterprise and data center networks. SR4.2 operates over two wavelengths at 850 nm and 910 nm just like currently popular 40 Gb and 100 Gb BiDi modules. Moreover, 400GBASE-SR8 operates at 850 nm over 8 pairs of MMF, each pair carrying 50 Gb/s at 850 nm. The 400GBASE-SR8 transceivers are commercially available and have been adopted by some large hyperscale customers.