In the 5G era, optical modules return to growth in the telecommunications market


5G construction will drive the rapid growth of demand for optical modules for telecommunications.In terms of 5G optical module requirements, it is divided into three parts: fronthaul, midhaul, and backhaul.

5G fronthaul: 25G/100G optical module

5G networks require higher base station/cell site density, so the demand for high-speed optical modules has greatly increased. 25G/100G optical modules are the preferred solution for 5G fronthaul networks. Since the eCPRI (enhanced common public radio interface) protocol interface (typical rate is 25.16Gb/s) is used to transmit the baseband signals of 5G base stations, the 5G fronthaul network will rely heavily on 25G optical modules. Operators are working hard to prepare infrastructure and systems to facilitate the transition to 5G. At its peak, in 2021, the domestic 5G required optical module market is expected to reach RMB 6.9 billion, with 25G optical modules accounting for 76.2%.

Taking into account the complete outdoor application environment of 5G AAU, the 25G optical module used in the fronthaul network needs to meet the industrial temperature range of -40°C to +85°C and dustproof requirements, and the 25G gray light and color light modules will Deploy according to different fronthaul architectures used in 5G networks.

The 25G gray optical module has abundant optical fiber resources, so it is more suitable for optical fiber point-to-point optical fiber direct connection. Although the optical fiber direct connection method is simple and low in cost, it cannot meet management functions such as network protection and monitoring. Therefore, it cannot provide high reliability for uRLLC services and consumes more optical fiber resources.

25G color optical modules are mainly installed in passive WDM and active WDM/OTN networks, because they can provide multiple AAU to DU connections using a single fiber. The passive WDM solution consumes less fiber resources, and passive equipment is easy to maintain, but it still cannot achieve network monitoring, protection, management and other functions; active WDM/OTN saves fiber resources and can achieve OAM functions such as performance overhead and fault detection, and Provide network protection. This technology naturally has the characteristics of large bandwidth and low delay, but the disadvantage is that the cost of network construction is relatively high.

100G optical modules are also considered to be one of the preferred solutions for fronthaul networks. In 2019, 100G and 25G optical modules have been set up as standard installations to keep up with the rapid development of 5G commercial and services. In fronthaul networks that require higher speeds, 100G PAM4 FR/LR optical modules can be deployed. The 100G PAM4 FR/LR optical module can support 2km (FR) or 20km (LR).

5G transmission: 50G PAM4 optical module

The 5G mid-transmission network has requirements for 50Gbit/s optical modules, and both gray and color optical modules can be used. The 50G PAM4 QSFP28 optical module using LC optical port and single-mode fiber can double the bandwidth through single-mode fiber link without installing a filter for wavelength division multiplexing. Through the shared DCM and BBU site amplification, 40km can be transmitted. The demand for 50G optical modules mainly comes from the construction of 5G bearer networks. If 5G bearer networks are widely adopted, its market is expected to reach tens of millions.

5G backhaul: 100G/200G/400G optical module

The 5G backhaul network will need to carry more traffic than 4G because of the higher performance and higher bandwidth 5G NR new radio. Therefore, the convergence layer and core layer of the 5G backhaul network have requirements for DWDM color optical modules with speeds of 100Gb/s, 200Gb/s, and 400Gb/s. The 100G PAM4 DWDM optical module is mainly deployed in the access layer and the convergence layer, and can support 60km through the shared T-DCM and optical amplifier. The core layer transmission requires high capacity and an extended distance of 80km, so 100G/200G/400G coherent DWDM optical modules are required to support the metro core DWDM network. Now, the most urgent thing is the 5G network’s demand for 100G optical modules. Service providers need 200G and 400G bandwidth to achieve the throughput required for 5G deployment.

In mid-transmission and backhaul scenarios, optical modules are often used in computer rooms with better heat dissipation conditions, so commercial-grade optical modules can be used. At present, the transmission distance below 80km mainly uses 25Gb/s NRZ or 50Gb/s, 100 Gb/s, 200Gb/s, 400Gb/s PAM4 optical modules, and the long-distance transmission above 80km will mainly use coherent optical modules (single carrier 100 Gb/s and 400Gb/s).

In summary, 5G has promoted the growth of the 25G/50G/100G/200G/400G optical module market.

Post time: Jun-03-2021