Information

Developed World largest capacity photonics transmission technologies

Realized world lowest power consumption per Gbps transmission capacity to reduce CO₂ emission by 70%

Fujitsu Limited succeeded in developing the world first digital coherent photonics transmission technology ^(*1) enabling 1.2Tbps ^(*2) per wavelength and confirmed its transmission capability over the equipment. The photonics network equipment with this technology is targeted to make a commercial release in the first half in the fiscal year 2023.

With rapidly growing demand for mass data processing technology as a result of the penetration of IoT, AI and Big data processing, further evolution of the network technology as the infrastructure to underpin such a demand is increasingly required.

The research and development of 5G-Advanced ^(*4) and 6G, as the next generation standards following 5G, which are now in widespread use, are progressing and the next generation standards are estimated to provide 100 times bigger data processing capacity than 5G when those are realized. With the increasing data access volume, larger capacity transmission is being required in photonics network area connecting in-between mobile base station and fixed core network. However, in the conventional technology, for further increase of transmission capacity per wavelength, there were the issues to overcome which are the restriction of modulation speed due to certain hindering factors such as optical distortion ^(*5), etc. In the meantime, the telecom carriers in the world have a challenge to reduce power consumption and CO₂ emission in their overall network operation.

[Overview of Technology]

With the unique key technologies consist of (1) Terabit-class photonics transmission system technology, (2) Liquid cooling method adopted to the transmission technology for the first time in the world and (3) Photonics network monitoring technology using ML, Fujitsu achieves the world largest capacity transmission and lowest power consumption at the same time and the technologies provides the backbone photonics network to underpin 5G and 6G era which contributes to create the carbon-neutral world.

The technologies are utilize part of the results of "Research and Development Project of the Enhanced infrastructures for Post-5G Information and Communication Systems, (b1)Research and Development of Terabit Optical Transport System for Post 5G Information Communication System" by New Energy and Industrial Technology Development Organization (NEDO) ^(*6), "Research and Development of innovative optical network technology as a new social infrastructure (Technological Theme I) (JP MI00316)" by the Ministry of Internal Affairs and Communications (MIC) and the commissioned research (No.20501) by National Institute of Information and Communications Technology (NICT), Japan.

1. World largest Terabit-class photonics transmission system technology

The world's first digital signal processing LSI (DSP) capable of transmitting 140 Gbaud ^(*7) high-speed signals and Narrow Spectral Line-width Wavelength Tunable Laser ^(*8) are used. Combining these technologies with Fujitsu's proprietary technology to precisely compensate for optical waveform distortions that occur in the transmitter/receiver devices and optical fibers, the world largest capacity of 1.2Tbpts per wavelength was realized. Generally, in the photonics transmission, the transmission distance shall be shorter when the transmission capacity increases. The transmission distance for the technology developed this time provides 4 times longer reach or more ^(*9) than the one for the conventional technology.

2. Liquid cooling method adopted to the transmission technology for the first time in the world

The conventional phonics network equipment applies air cooling method for cooling down the heat in the equipment. Fujitsu has adopted the liquid cooling method to the phonics network equipment for the first time in the world by making use of its knowledge gained through the development and manufacture of super-computing. Whilst keeping the high reliability and maintainability required for transmission equipment to be used for long term operation, Fujitsu improved the cooling efficiency and realized 120mW, the record low power consumption per Gbps transmission. As compared with the previous equipment based on air cooling method, the overall equipment size and weight is reduced to one third and the reduced size and weight contribute to the reduction of CO₂ emission during logistics and at the disposal after retirement of equipment.

3. Photonics network monitoring technology using ML

In order to secure the required communication capacity in a stable manner at all times, conventional photonics networks were designed based on strict estimates of conditions such as optical fiber performance depending on the operating environment and optical transmission system conditions. The performance of the network could not be efficiently exploited, resulting in increased power consumption and reduced transmission capacity. The photonics network monitoring technology using ML enables to capture the status of each network elements such as fiber characteristic, equipment performance, etc. automatically and accurately for analysis and the outcome of analysis will help the optimized pre-setting of DSP modulation and network elements, which maximize transmission performance whilst reducing the required power consumption as a minimum.

• *1
  "Digital coherent photonics network technology" is the cutting edge technology to maximize the transmission performance by the combination of coherent receiving system improving the sensitivity of receiver utilizing the frequency and phase of an optical carrier signal and ultra-high performance digital signal processing.
• *2
  "1.2Tbps" is the transmission capacity enabling the data transmission equivalent to the capacity accommodated in 6 blue ray disks (25G per disk) at every second.
• *3
  "Best in the world transmission performance": As of 31 August 2022, As a result of internal investigation.
• *4
  "5G-Advanced" is the transmission standard improving 5G transmission performance further, of which standardization is progressed by 3GPP (3rd Generation Partnership Project) being the standardization body of wireless technology.
• *5
  "Optical waveform distortion" is the phenomena caused by large-capacity transmission with wider bandwidth sometimes affecting transmission performance.
• *6
  "Research and Development Project of the Enhanced infrastructures for Post-5G Information and Communication Systems,(b1)Research and Development of Terabit Optical Transport System for Post 5G Information Communication System" This research and development project involves Fujitsu Optical Components Limited and Furukawa Electric Co., Ltd. in addition to Fujitsu Limited.
• *7
  "Baud" is the unit showing signal modulation speed. The bigger figure is enabled, the larger transmission capacity can be achieved. The technology this time provide faster speed by more than two times than the one for conventional technology.
• *8
  "Narrow Spectral Line-width Wavelength Tunable Laser" A light source that increases the purity of the wavelength emitted by the laser and can be set to any wavelength required for photonics transmission to achieve high-capacity and long-distance digital coherent optical transmission.
• *9
  "4 times longer reach or more" When the newly developed photonics transmission system is operated with a transmission capacity of 800 Gbps, it achieves a transmission distance more than four times greater than that of conventional equipment.

Contacts :
Fujitsu Limited, Japan
Photonics System Business Unit
contact-photonics-information@cs.jp.fujitsu.com