As forecasted bandwidth requirements continue to increase, service providers are looking to extend 100G transmission into the 80km links in their access networks. 100G over 80km would enable these network operators to future-proof their access networks efficiently without extensive re-architecting. However, traditional direct-detect 100G transceivers are limited to 40km. As such, we’ve received a number of inquiries about possible solutions to this challenge. In this article, we’ll look at the unique benefits of two options to consider.
Option 1: Coherent Optics
As we’ve discussed recently, coherent technology improves upon this by using more complex light modulation schemes that use one lane to reach much longer distances. For example, our DCO (digital coherent optics) CFP2 transceivers offer multiple modulation schemes that enable 100G transmission up to 2000km, and 200G transmission up to 800km! These transceivers use the DWDM ITU channel grid.
Unlike the earlier analog coherent optics (ACO), DCO optics contain required hardware for coherent 100G/200G transmission, which simplifies the deployment process. However, they do require a specific DCO-enabled port.
Option 2: PAM4
PAM4 (4-level Pulse Amplitude Modulation) is another technology that takes advantage of additional characteristics of light to offer long-distance 100G transmission in a compact QSFP28 form factor. While these optics are less expensive individually than DCO optics, they require an active line system to provide the required amplification, attenuation, and dispersion compensation. While the transceivers themselves are rated at 80km, it is possible to reach much longer (up to 120km) with the correct levels of amplification from the active line system.
Like coherent transceivers, PAM4 transceivers use the same 50GHz-spaced DWDM channel grid. As such, the mux/demux component of a PAM4 active line system can bring together up to 40 links of 100G each, for up to 4TB of total network capacity!
Champion ONE is currently preparing full public launches of both coherent and PAM4 solutions. For more information about these solutions and how to receive an early complimentary lab evaluation, contact us today.
