Rising data requirements and consumption are fueled by growing demand in 5G, AI, cloud, streaming and other applications. Statista projects that in the next two years, monthly internet traffic will grow by at least 15 exabytes.Greater adoption of ultra-high data rate fiber solutions in data centers will be conducive to improving network performance for these applications. Despite growing data demands, however, utilizing traditional fiber technology in ultra-broadband networks brings about cost concerns. Technical constraints and limitations of legacy optics technology also hinder performance when it comes to power consumption and heat generation.
The development of 400Gb technology represents a major breakthrough in fiber optics development. 400Gb solutions address many of the aforementioned concerns while delivering the ultra-high data rates needed for advanced networks. With the continued maturation of 400Gb technology, legacy optics solutions will be gradually phased out as service providers transition to wide-scale, ultra-broadband networks. 400Gb solutions offer a clear-cut upgrade path to 800Gb data networks, allowing for greater hyper scaling.
Leveraging PAM4 and silicon photonics
Advanced modulation schemes are used in newer generation fiber solutions to increase data rates. While NRZ (non-return to zero) modulation is often utilized by 10Gb, 25Gb, and 50Gb transceivers in long haul networks, the primary drawback of NRZ is that it requires a significantly higher fiber count, increasing costs and optical complexity. Once networks surpass the 100Gb data rate threshold, the large-scale deployment of NRZ modules becomes less economically and logistically viable.
This has led to the implementation of PAM4 (Pulse-Amplitude Modulation 4-Level) modulation in 400Gb transceivers. PAM4 carries two bits per transmission interval which doubles the throughput per channel at equivalent levels of bandwidth compared to NRZ. The higher throughput means PAM4 transceivers can deliver twice the amount of data compared to an NRZ transceiver, without adding extra fiber that would be needed with a NRZ transceiver. With higher throughput per transceiver, PAM4 greatly cuts down on the amount of fiber needed, reducing costs and optical complexity in ultra-broadband networks.
The implementation of silicon photonics on select 400G transceivers addresses the issue of excess heat generation. Silicon photonics-based transceivers use silicon as an optical medium which curbs power consumption and reduces the amount of heat generated. Both PAM4 modulation and silicon photonics have sparked a paradigm shift in the optics industry, challenging conventional fiber optics design and driving the advancement of 400Gb technology. Going forward, the general industry consensus is that PAM4 modulation is the most suitable modulation scheme for networks with data rates of 400 Gbps and higher. Gartner reports that the impending migration to 400G, declining cost and heterogeneous packaging are all creating new opportunities for silicon photonics in data centers.
The Axiom Connectivity 400Gb lineup
Axiom Connectivity’s 400Gb lineup features an assortment of QSFP-DD 400Gb and OSFP-400Gb solutions with reach specifications ranging from 100m to 40km. With its utilization of PAM4 modulation and silicon photonics, Axiom Connectivity’s 400Gb lineup circumvents the high costs of adding fiber and reduces overall power consumption. With eight electrical lanes on both the QSFP-DD and OSFP form factors, each transceiver offers eight channels of 50Gbps data rates for a combined 400Gb data rate.
The compact sizing of hot-pluggable QSFP-DD and OSFP form factors ensures that the transceivers can be seamlessly integrated into network infrastructures. The QSFP-DD solution also offers backwards compatibility, enabling network providers to retrofit legacy infrastructures with 400Gb solutions.
Building 400Gb networks is a major step towards futureproofing networks. To learn more about our extensive offering of advanced 400Gb solutions, contact an Axiom Connectivity representative.
 “Estimated internet traffic in the United States from 2018 to 2023,” Statista, accessed April 30th, 2021, https://www.statista.com/statistics/216335/data-usage-per-month-in-the-us-by-age/
 “Market Trends: Top 3 Drivers for Silicon Photonics Adoption in Data Centers,” Gartner, accessed May 3rd, 2021, https://www.gartner.com/en/documents/3995474/market-trends-top-3-drivers-for-silicon-photonics-adopti