IPEC Initiates Research Project for Next-Generation Mobile Fronthaul MFH50 Standards

2022-04-08 Source:

With the large-scale commercial use of 5G networks and sharp increase of mobile Internet traffic around the world, an increasing amount of spectrum resources are also being released. Alongside this, mobile network technologies are being iterated rapidly to meet the increasing requirements for high-speed data interconnection. Mobile fronthaul links between baseband processing units connected to a base station system and radio frequency (RF) units play an important role in ensuring transmission performance and the quality of 5G and next-generation mobile communication networks. Subsequently, they are now a major focus on research in many new mobile communication networks and transmission technologies.

Mobile fronthaul in mobile networks

Mobile fronthaul in mobile networks

During the early stages of 5G construction, wireless vendors selected 25 Gbit/s as the typical rate of fronthaul eCPRI interfaces. In making the decision, vendors considered the available spectrum bandwidth and base station processing function re-division. The 5G fronthaul solution has evolved from the direct single-fiber unidirectional/bidirectional connection solution to solutions using multiple transmission technologies, such as passive, semi-active, and active WDM solutions. Since then, 5G has been put into commercial use on a vast scale, and most operators have started to deploy high-bandwidth mobile services. For example, China Telecom and China Unicom joined hands to co-construct and share 200 MHz spectrum resources. China Mobile has also deployed a 160 MHz ultra-broadband spectrum. As a result of this extensive advancement, a need has developed for the construction of multiple sets of 25G WDM solution systems or a solution system with more wavelengths. However, scenarios such as massive multiple-input multiple-output (MIMO) base stations, U6G band base stations, and 5G millimeter-wave base stations will soon be demanding more channels; this means operators will likely need to add more ports and consume more optical fibers to meet the bandwidth requirements of next-generation wireless networks. In consequence, the difficulty of large-scale 5G deployment will further increase. However, there are still ways to ease impending pain points; for instance, if the single-channel rate can be upgraded from 25 Gbit/s to 50 Gbit/s, 50% of ports can be saved, creating the opportunity for a more flexible improvement of fronthaul bandwidth.

To drive the rapid maturity and healthy development of the mobile fronthaul 50G industry, the International Photonics & Electronics Committee (IPEC) approved the Mobile Fronthaul 50G (MFH50) standards project. This project was proposed by the Network Requirement Work Group, Physical Media Dependent (PMD) Work Group, and Form Factor Work Group at the joint work group meeting in February 2022. It is dedicated to researching next-generation fronthaul systems and focuses on the application of single-channel 50 Gbit/s links in mobile fronthaul.

IPEC’s MFH50 research falls into two segments: optoelectronic component technology and its engineering deployment. Optoelectronic component technology research covers optoelectronic parameters of optical modules, optical parameters of passive multiplexers/demultiplexers, low power consumption technologies of optical modules, and O&M features of optical modules and fronthaul links. Engineering deployment research explores fronthaul link quality and fronthaul link engineering optimization solutions. The research aims to enable faster MFH50 optical module deployment with higher quality based on big data analysis of existing parameters such as fronthaul fiber link parameters and operating ambient temperatures of optical modules. IPEC is also considering starting MFH50 test platform projects, which focus on fronthaul optical module deployment, acceptance method research, and optical module deployment research. For example, this could involve researching unified test and acceptance solutions for electromagnetic compatibility and reliability of optical modules, as well as passive multiplexers/demultiplexers to improve the delivery quality of related components and the reliability of base stations.

Currently, the industry chains of components, including ports, electrical chips, and optical chips, involved in the MFH50 project are mature. However, optical module design still faces two technical challenges.

First, the power consumption of optical modules is gradually increasing. 50 Gbit/s fronthaul links introduce new components to optical modules to support or implement four-level pulse amplitude modulation (PAM4). In this case, the power consumption of optical modules slightly increases, and their temperatures increase accordingly. However, maintaining the temperatures of optical modules at a low level is critical to the stability and reliability of fronthaul links. In addition, heat dissipation of RF modules also affects the temperatures of optical modules.

The second challenge is the complexity of fronthaul links. Compared with fiber links in data centers, fronthaul fiber links at base stations have more technical and engineering uncertainties. Possible contamination of optical connectors and return loss of fiber splicing points pose strenuous challenges to the optoelectronic parameters of MFH50 optical modules.

In the MFH50 project, after in-depth discussion, multiple high-quality proposals have been submitted on the existing fronthaul link surveys, optical module line rate specifications, electrical interface parameters and acceptance test solutions, optical parameters of gray optical modules and passive multiplexers/demultiplexers, and O&M requirements of optical modules. The next step of the project will focus on the formulation of the Fronthaul Link White Paper and the research on the optical parameters of multiplexers/demultiplexers.

Currently, the MFH50 project has attracted the attention and obtained promotion of over 10 IPEC members, including operators, equipment vendors, optical module vendors, electrical chip vendors, and research institutes. Going forward, the MFH50 project will continue to focus on addressing issues and challenges in fronthaul scenarios, and will bring the whole industry together to promote the standardization, innovation, and industry application of 50G optoelectronic technologies in the fronthaul field.


About IPEC (www.ipec-std.org)

The International Photonics & Electronics Committee (IPEC) is an international standards organization that is committed to developing open optoelectronic standards and delivering strategic roadmap reports. IPEC focuses on standardizing solutions in optical chips, optical/electrical components, and optical modules. Markets addressed by IPEC include 5G, IoT and AI.

By February 2022, the number of IPEC members has increased from 13 to 33. Currently, the IPEC members include China Telecom, China Academy of Information and Communications Technology (CAICT), Meituan, Huawei, FiberHome, Broadex, CIG Shanghai Co., Ltd., Wenzhou Yihua Connector, Fujitsu Optical Components (FOC), Hisense Broadband, HG Genuine, Source Photonics, Yamaichi, AOI, InnoLight, ZTE, AROPTICS-TECH, Mindsemi, Accelink, O-Net, H3C, YOFC, Foxconn, Shanghai Jiao Tong University, Sitrus Technology, Semtech, Advanced Fiber Resources, ATOP Corporation, SiFotonics, Intel, Acon Optics, JONHON, and Suzhou GL Foresight Electronic Technology.

IPEC is open to any interested party who wishes to join. All members have the opportunity to participate in developing all IPEC standards and reports on a non-discriminatory basis. The process of developing these standards and reports is transparent to all members. IPEC is registered in Switzerland.

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