Innovative FS 800G Transceiver Solutions for Leading Future Networks

In the era of data-driven technology and high-speed communication, the demand for faster and more reliable networks is greater than ever. As businesses and service providers strive to meet the growing need for bandwidth driven by advancements in cloud computing, big data, and artificial intelligence, Ethernet technology must evolve accordingly. This article explores the technical solutions offered by 800G transceivers, providing the speed and efficiency necessary to support the next generation of high-performance applications.

The Transition from 400G to 800G Transceivers

Data traffic is growing exponentially, and traditional networking speeds are no longer sufficient to handle the surge in data processing and transmission requirements. In response, the industry is moving toward 800G transceivers. While 400G will remain prominent until around 2023, 800G is expected to become the dominant standard by 2025. This transition to higher networking speeds, such as 800G, will be driven by several factors:

1. Data Centre Modernisation: With the proliferation of cloud services, data centres must upgrade their interconnects to handle vast amounts of data efficiently.

2. High-Performance Computing and AI: HPC and AI applications require rapid data transfer rates to process large datasets and perform complex calculations.

3. Telecommunications Expansion: As 5G networks roll out, telecommunications companies need faster backhaul connections to support increased mobile traffic and new services.

                                                                          Figure 1 400G to 800G Transceivers Transition

800G SR8 Short-Range Technical Solution

For 800G short-range applications, traditional multimode fibre limits the transmission distance to less than 50 metres. Even with the latest OM4 and OM5 multimode fibres, it's hard to reach 100 metres. Recognising these constraints, the working group of industry experts focusing on 800G pluggable modules has agreed to discontinue the use of VCSEL-based multimode solutions for distances of up to 100 metres. Instead, they have chosen to adopt the PSM8 transmission technology, which utilises parallel transmission over single-mode fibres.

To achieve ultra-fast 800G SR8 speeds, a common method is to use PAM4 modulation along with advanced Digital Signal Processor (DSP) chips. The current 800G SR8 solutions can be broadly categorised into two main technologies: one based on Directly Modulated Laser (DML)/Electro-Absorption Modulated Laser (EML) technology and another relies on Silicon Photonics (SiPh). Details of these configurations can be seen in Figures 2 and 3.

One approach to the 800G SR8 solution uses eight 100G DSPs, which may be replaced with an analog clock data recovery unit for a simpler and more efficient design. This design is built around DML or EML optical chips that all operate on the same wavelength, ensuring synchronised light signal transmission. For efficient data transfer, the solution uses eight optical fibres on each end for transmission and reception, creating a parallel single-mode fibre system with eight channels. It typically uses 24-core or 16-core MPO connectors.

                                                                          Figure 2 8×100G SR8 DML/EML

Another method for 800G SR8 employs SiPh technology, utilising eight SiPh Mach-Zehnder modulators or Continuous Wave lasers. Employing SiPh as the transmitter and separating the modulators from the light sources, this solution allows for a shared light source architecture that enables parallel multi-channel transmission. With controlled insertion losses, one or two light sources can power eight parallel channels, offering a significant cost advantage.

                                                                          Figure 3 8×100G PSM8 SiPh

800G DR/FR Mid-Range Interconnect Solution

When it comes to 800G interconnects over a 500-metre distance, using eight channels of 100G with SiPh technology doesn't cut costs much compared to the 400G DR4 SiPh option. Opting for a configuration with four channels, each running at 200G, actually saves more money. However, the reliability of the 100G components remains under scrutiny for broader application. Despite the higher cost, the eight-channel parallel solution could be achievable initially under the Multi-Source Agreement (MSA).

As shown in Figure 4, the 800G DR4 solution employs four 200G DSPs for signal processing, paired with EML or SiPh optical chips that operat at a unified wavelength. The design bypasses DML due to its limitations in bandwidth expansion. On both the transmission and reception ends four PSM4 fibres are used, which are parallel single-mode channels, all transmitting at the same wavelength, these fibres are connected using 12-core MPO connectors for efficient and compact interfacing.

                                                                          Figure 4 4x200G PSM4 EML/SiPh

For 800G data transfers over 2 kilometres, the single-channel 200G PAM4 technology is the new frontier in optical communication, providing the foundation for 4-channel 800G connections. Doubling the speed from 100G to 200G increases the baud rate but also slightly reduces sensitivity by about 3dB. To maintain high receiver sensitivity at approximately -5dBm, the system is enhanced with robust forward error correction—FEC. This ensures that despite the increased speed, the signal remains clear and errors are corrected efficiently.

The 800G FR4 EML solution utilises a four 200G DSPs and CWDM4 EML chips. At both the transmitting and receiving ends, a wavelength division multiplexer is employed to efficiently combine and separate these signals onto a single fibre strand that adheres to the CWDM4 standard. The physical connections between the devices are made using dual LC. This configuration is intended to optimise bandwidth usage and ensure a high-speed data transfer rate, as illustrated in Figure 5.

                                                                          Figure 5 4x200G CWDM4 EML

800G LR/ER/ZR Long-Range Connectivity Solution

To address the 800G requirements for 10-kilometre connections, the industry has proposed four solutions considering dispersion constraints.

1. 800G LWDM8 or nLWDM8: Utilising a long wavelength division multiplexing (LWDM) or a narrow linewidth LWDM (nLWDM) with 8 channels to increase the transmission capacity while managing dispersion.

2. 800G LWDM4 or nLWDM4: Employing a 4-channel LWDM or nLWDM setup for a balance between capacity and dispersion control.

3. 800G Self-Heterodyne Detection (SHD) Coherent: Implementing a coherent detection technique that uses self-heterodyning to enhance signal quality and mitigate dispersion effects.

4. 800G Coherent: Applying a general coherent optical communication method that provides superior dispersion tolerance and signal integrity for high-speed data transmission.

As depicted in the Figure 6, the 800G LR8 solution employseight 100G DSPs paired with LWDM8 EML optical chips. At both the transmitter and receiver, wavelength division multiplexers are employed to efficiently combine and separate signals over a single LWDM8 fibre, while dual LC connectors ensure a robust and precise optical link.

                                                                          Figure 6 8x100G LWDM8 EML

The 800G LR4 solution employs four 200G DSPs and four EML chips, each operating at distinct LWDM4 wavelengths. At the receiving end, 200G PAM4 avalanche photodiodes (APDs) are used for sensitive signal detection. As shown in Figure 7, wavelength division multiplexers are deployed at both the transmitting and receiving ends, with each end linked by a single LWDM4 fibre, ensuring efficient signal transmission and reception through dual LC connectors.

                                                                          Figure 7 4×200G LWDM4 EML

There are currently two options for wavelength selection: LWDM4 with an 800GHz wavelength spacing and nLWDM4 with a denser 400GHz spacing. The nLWDM4 scheme boasts the benefits of diminished dispersion-related costs and a decrease in both the power requirements and the computational complexity of the DSP. However, to realise these benefits, the development of new EML chips is necessary, indicating a need for innovation in optical component technology.

For more extensive reaches of 40km and 80km, the industry has adopted an 800G coherent solution. This method leverages dedicated coherent DSPs and 128 Gigabaud integrated coherent transmitter-receiver optical sub-assemblies (IC-TROSAs), along with dual LC connectors for stable and efficient data transmission.

A Closer Look at the FS 800G Transceiver Family

Building on the advances in 800G technology, the transition from 400G to 800G is not merely about achieving faster speeds—it marks a significant transformation accompanied by a range of innovative solutions. The FS series of 800G transceivers provides a variety of options specifically designed to meet the growing demands of high-speed networking.

• 800G SR8: Empowering data centres with VCSEL technology, FS 800G SR8 module boasts low power usage, cost efficiency, and robust reliability. Operating at an 850nm wavelength with a single-channel speed of 100Gbps PAM4, it requires 16 fibres. As an enhanced version of the 400G SR4, it doubles the channel count, enabling high-speed 800G data interconnections within 100 metres.

• 800G DR8: Designed for longer-distance transmission, the 800G DR8 module supports up to 500 metres over single-mode fibre (SMF) with dual MTP/MPO-12 connectors. This transceiver complies with IEE802.3ck, IEEE 802.3cu and OSFP MSA standards. Ideal for 800G Ethernet, breakout 2x 400G DR4 or 8x 100G DR, data centre and cloud networks.

• 800G FR4: The 800G FR4 module can transmit data over single-mode fibre for distances up to 2 kilometres, seamlessly integrating with existing network infrastructure while preparing businesses for future bandwidth expansion. Its eight 100G PAM4 signal channels offer excellent signal integrity and low error rates, ensuring stable and reliable high-speed data transmission.

• 800G LR: FS 800G LR module supports up to 10km link lengths over SMF with MTP/MPO-16 connectors. The built-in digital diagnostics monitoring (DDM) allows access to real-time operating parametres. Built-in Broadcom DSP chip, the 800G transceiver offers high-speed, and low-power in 800G links.

                                                                          Figure 8 FS 800G Transceivers

With FS comprehensive suite of 800G transceivers, businesses and service providers can future-proof their networks, ensuring they are ready for the exponential growth in data traffic driven by emerging technologies and applications.

Learn more about 800G Transceiver: Demystifying 800G Transceiver: Types, Applications, and FAQs

Conclusion

800G transceivers are at the forefront of addressing the growing need for faster and more efficient data transmission. Their advanced technology supports high-speed, high-bandwidth applications, making them essential for modern network infrastructure. By offering robust performance and scalability, 800G transceivers are set to revolutionise connectivity across industries.

FS is a leading innovator in network solutions, committed to providing high-performance, reliable, and cost-effective products that drive the future of connectivity. FS 800G transceivers are designed to meet the demands of next-generation networks, offering unparallelled speed and efficiency. Choose FS innovative 800G transceiver solutions to empower your network and lead the way into the future of connectivity.