The Technical Solutions of FS 800G Transceivers

Market Forecasting and Application Scenarios of 800G Transceivers

As cutting-edge advancements like 4K VR, IoT, and cloud services gain traction, networks need to support enhanced capacity, simultaneous user engagement, and instantaneous processing. Industry analysts from Omdia have projected a consistent upsurge in bandwidth requirements for years ahead. Despite the current prevalence of 100, 200, 400, and 800G fiber optic components, projections indicate that 800G will have widespread implementation by 2025.

Figure 1 illustrates an 800G network setup where rack-mounted switches are connected to their leaf counterparts over varying lengths, ranging from several meters up to a few hundred meters, while leaf-spine and spine-core router connections accommodate internal or nearby inter-campus connectivity needs, extending from 2km to occasionally 10km; major web-based companies that have historically utilized 100G solutions started transitioning to 200G or 400G as of 2021, with some pioneers targeting to pilot 800G tech within 2023.

In the context of Data Center Interconnects (DCI), which typically cover load redistribution or standby links for disaster recovery amongst neighboring data hubs, the links might encompass multiple kilometers. To optimize the use of precious fiber optics, technologies like DWDM and coherent transmission are leveraged for optimal reuse. The deployment possibilities for 800G fiber modules span short-range SR (up to 100m), middle-range DR/FR/LR (500m, 2km, 10km), and extended-range ER/ZR (40km, 80km), addressing a broad spectrum of operational distances.

Evolution of the 800G Technology Solution

Three distinct stages have marked the progression of 800G tech.

First Stage: Introduced an 8x100G dual interface (both optical and electrical), which hit the market in 2021.

Second Stage: Set to launch in 2024, this phase brings a half-optical, full-electrical configuration, delivering 4x200G optically and maintaining 8x100G electrically.

Third Stage: Slated for 2026, this iteration maintains the optical throughput of the second stage but streamlines the electrical interface to match it, 4x200G.

Looking ahead over the next five years, pervasive adoption is anticipated for solo-channel 200G technologies across both optics and electrics. Yet, within the nearer span of three years, the nascent state of singular 200G channel chips and requisite equalization techniques means the sector will need additional time to surmount existing technological hurdles.

Advancement in Standardizing Protocols

Key international standard-setting entities, including IEEE 802.3 and industry groups like 800G Pluggable MSA, 100G Lambda MSA, as well as IPEC, are at the forefront of establishing criteria for 800G bandwidth technologies. This process encompasses outlining the vital use cases and detailing the connection standards for the optical units.

The 800G Pluggable MSA has put forth criteria for the 8x100G PSM8, designed for cost-effectiveness and supporting up to 100 meters of transmission, alongside specifications for the 4x200G FR4, which is aimed at achieving up to 2 kilometers of transmission range. Concurrently, QSFP-DD800 MSA has been pivotal in steering the QSFP-DD hardware towards accommodating 800G, aligning with the most recent QSFP-DD MSA updates. These collective endeavors in standardization are pivotal in propelling the integration and usage of 800G technology across various platforms.

Technical Solutions for 800G SR8 Scenarios

The bandwidth constraints of traditional multi-mode optical fibers impede the ability to maintain high-speed data rates like 800G over distances exceeding 50 meters. Extending transmission to 100 meters poses a significant hurdle, even when deploying advanced OM4 or OM5 multi-mode fibers. Given such limitations, the collective working group of industry experts focusing on 800G pluggable modules have unanimously opted to avoid using VCSEL-dependent multi-mode strategies for spans reaching 100 meters. The selected alternative leverages a system based on parallel transmission over single-mode fibers, specifically designed for PSM8 configurations.

For the implementation of ultra-fast 800G SR8 applications, a prevalent strategy involves the combination of PAM4 modulation techniques integrated with sophisticated DSP chips. Current innovations to cater to the 800G SR domain mainly consist of configurations that rely on both DML/EML and SiPh technologies, with illustrative images accessible in Figures 3 and 4.

The SR8 solution utilizing DML/EML involves eight DSPs each executing at a transfer rate of 100G, potentially alongside analog clock data recovery mechanisms, coupled with optoelectronic elements operating at uniform frequencies. To facilitate data exchange, the solution implements eight single-mode fibers on both the sending and receiving terminals and establishes connections with either 24-core or 16-core MPO connectors.

Conversely, the SR8 framework based on SiPh technology incorporates eight channels driven by either SiPh Mach-Zehnder modulators or Continuous Wave lasers. By separating the modulating components from the light-generating elements, this method enables a distributed multi-channel system that can be powered by a singular light source. With controlled insertion losses, it's feasible for one or two light sources to cater to all eight channels concurrently, which can lead to cost efficiencies.

FS 800G SR8 Optical Transceivers

As a leading manufacturer in the communication field, FS has also introduced its own 800G SR8 module to meet high-bandwidth demands. FS's 800GBASE-SR8 optical transceiver offers both QSFP-DD and OSFP packaging options, catering to Ethernet and InfiniBand networks respectively. The QSFP-DD package uses an MTP/MPO-16 connector, while the OSFP package utilizes an MTP/MPO-12 connector, supporting a multimode fiber link length of up to 50 meters. The module complies with IEE802.3ck, CMIS 5.0, and MSA standards, featuring built-in digital diagnostics monitoring (DDM) functionality for real-time access to operational parameters. The FS 800G SR8 module provides high-speed connectivity for data center architectures, enabling them to cope with the ever-increasing demands of data traffic and network performance. Besides, InfiniBand OSFP-SR8-800G, used in Quantum-2 air-cooled switches, has a large quantity of stock and is ready to expand your HPC networks.

Technical Solutions for 800G DR/FR Scenarios

In considering the requirements for a half-kilometer connection with a speed of 800G, evaluating the setup employing eight channels of 100G silicon photonics reveals possible limitations in cost efficiency when compared to the 400G Density Ratio 4 (Dual-Rate 4) Silicon Photonics alternative. Yet, the use of four channels, each at 200G, might provide a better economic outlook, even though the production success rates of devices operating at 100 Giga-baud must be weighed. Initially, the eight-lane parallel configuration may still be regarded as an achievable standard under the Multi-Source Agreement framework.

Examination of Figure 5 discloses that the 800G Density Ratio 4 (Electro-absorption Modulated Laser/Silicon Photonics) structure uses digital signal processors each managing 200G. Four Electro-absorption Modulated Laser/Silicon photonics modules are chosen, all tuned to the same frequency. Directly Modulated Lasers are disregarded due to bandwidth limitations. The setup requires four single-mode fibers (with a four-channel parallel single-mode symmetry) for signal conveyance, and multi-fiber push-on connectors with 12 fibers enable the connection.

At a two-kilometer span for 800G transfers, the single wavelength, dual amplitude modulation at 200G has been recognized as the prospective standard for straightforward modulation and detection systems. This foundation is instrumental in crafting four-way 800G fiber links. Doubling the speed from 100G to 200G induces an approximate 3dB degradation in sensitivity, which means augmented error correction protocols must be introduced to ensure enhanced receptor sensitivity (targeting -5dBm).

Employing four 200G digital signal processors, the 800G FR4 based on Electro-absorption Modulated Laser technology is outlined. At both the sending and receiving sides, wavelength-division multiplexing (Coarse Wavelength Division Multiplexing 4) is utilized, involving a singular optical fiber. As illustrated in Figure 6, the physical connections rely on paired Lucent Connectors.

FS 800G DR Optical Transceivers

The FS 800GBASE-DR8 optical transceiver is designed for 800GBASE Ethernet throughput up to 500m over single-mode fiber (SMF) with MPO-12/16 connectors, offering an unparalleled 800Gbps of bandwidth that caters to the ever-growing need for faster and more efficient data transfer. It adopts a built-in Broadcom 7nm DSP chip and EML laser and has a maximum power consumption of 16.5W. This powerhouse of a transceiver is crafted with precision, allowing for energy-efficient operations that significantly reduce the cost per bit, thereby not only accelerating network performance but also promoting environmentally friendly practices. It is suitable for 800G Ethernet or InfiniBand, data center, breakout 2x400G DR4, or 8x100G DR application.

FS 800G FR Optical Transceivers

The FS 800G FR4 optical transceiver is engineered to comply with the 800GBASE-FR4 specification, this transceiver boasts a reach of up to 2 kilometers over single-mode fiber, seamlessly integrating with existing network infrastructures while preparing businesses for future bandwidth expansion. Its 8 lanes of 100G PAM4 signals exhibit exceptional signal integrity and low bit error rates, which can translate into stable and reliable high-speed data transfers.

Incorporating the latest in coherent optical technology, the FS 800G FR4 Optical Transceiver is optimized for power conservation, helping to reduce operational costs and carbon footprint, providing a clear path for network evolution without the need for significant hardware overhauls.

Technical Solutions for 800G LR/ER/ZR Scenarios

Addressing the need for a 10km interconnect at a capacity of 800G, the sector has introduced four innovative pathways to circumvent issues related to dispersion boundaries: the employment of 800G long-wavelength division multiplexing with eight or no spacers, the utilization of four spacers or no spacers at the same rate, a self-homodyne detection variant and a coherent transmission strategy for the same bandwidth.

Depicted in Figure 7 is an 800G Long Reach 8 configuration that integrates eight digital signal processing components functioning at 100G each, alongside long-wavelength division multiplexing with eight Electro-absorption Modulated Lasers as optical components. In this setup, a singular fiber is used for signal transmission and reception across each site, utilizing a long-wavelength division multiplexing technique with eight divisions. Connection is realized through the use of a pair of Lucent-style connectors.

The Long Reach 4 arrangement for 800G capitalizes on four digital signal processors each supporting 200G, accompanied by four Electro-absorption Modulated Lasers operating on long-wavelength division multiplexing with four divisions. At the receiving end, this strategy incorporates waveguided avalanche photodiodes for 200 G 4-Level Pulse Amplitude Modulation signals, as shown in Figure 8. A singular fiber optic line is deployed for both transmitting and receiving ends, implementing a wavelength-division multiplexing paradigm with four divisions. Like its counterpart, this design also leverages a dual Lucent-style connector mechanism for interfacing.

With regards to choosing an appropriate frequency separation, the industry is deliberating between the long-wavelength division multiplexing with a spacing of 800 GHz and the narrower option of 400 GHz. The narrower alternative shines in its ability to decrease dispersion overhead, curtail power usage in digital signal processors, and simplify architecture, albeit it demands the innovation of new Electro-absorption Modulated Laser components.

For more extensive reaches of 40km and 80km, the sector has agreed upon a coherent transmission protocol at 800G. This method leverages specialized coherent digital signal processors, employs 128 Giga-baud Integrated Coherent Transmitter and Receiver Optical Sub-Assemblies, and establishes connections through the utilization of paired Lucent-style connectors.

FS 800G LR Optical Transceivers

The FS 800G LR Optical Transceiver delivers lightning-fast connectivity over a long-reach single-mode fiber, maintaining signal integrity across distances of up to 10km. Engineered for reliability and top-notch performance, it embodies low power consumption and is equipped with the latest in FEC (Forward Error Correction) technology to ensure data integrity. Compatible with QSFP-DD and OSFP form factors, it seamlessly integrates into existing infrastructure, providing an efficient and cost-effective upgrade path without the need for extensive system overhaul. Each transceiver undergoes rigorous testing to ensure high quality.

Conclusion

In conclusion, the FS solution to 800G transceivers encapsulates innovation, efficiency, and reliability. By focusing on advanced modulation formats, sophisticated error correction, and effective thermal management, FS has positioned itself as a provider of high-quality and forward-thinking transceiver solutions that not only promise to deliver the high-speed data transfers that today's data centers require but also pave the way for future advancements in optical networking. As data center demands evolve, FS's commitment to technical excellence will continue to provide customers with solutions that enable progress and connectivity at a global scale.