Do you know how optical modules are used in base stations?

Communication tower must be no stranger to you, this article for you to introduce the communication tower under the base station and optical module in the base station application.

The communication triangle tower is composed of antennas, machine rooms, base stations, feeders and supporting equipment. The antenna is on the top of the triangle tower, and there will be a machine room under the tower. The machine room is mainly for the base station, which is the equipment for transmitting wireless signals. The base station is logically divided into two parts: BBU and RRU. RRU is responsible for sending and receiving signals, while BBU is responsible for signal processing. The feeder is used to connect the antenna and the base station, and the supporting equipment is mainly power supply and air conditioning.

In distributed site, the base station BBU and RRU work separately. RRU is hung on the tower, while BBU is placed in the machine room under the tower. CPRI protocol transmits physical layer data between BBU and RRU, which not only contains the data carried, but also contains a lot of physical layer information.

The transmission carriers connecting BBU and RRU devices are optical modules and optical fibers. In 2/3/4G networks, optical modules of 10Gbps are generally used for CPRI interfaces. In 5G networks, CPRI will be upgraded to eCPRI.

The following describes the types of optical modules used by 10G SFP+ and 25G SFP28 to connect the BBU to the RRU device.

1. 10G SFP+ CPRI SR 300M (industrial grade)

The product model is ES85X-3LID03, which uses 850nm VCSEL laser and PIN photodetector, working temperature range is -40℃-85℃, in line with SFP28 MSA, IEEE 802.3 25GBASE-SR Ethernet and CPRI standards. The transmission range is up to 300m (OM3) through multi-mode optical fiber.

2, 25G SFP28 CPRI/eCPRI SR 100M (industrial grade)

The product model is ES2852X-3LID01, which uses 850nm VCSEL laser and PIN photodetector, the working temperature range is -40℃-85℃, in line with SFP28 MSA, IEEE 802.3 25GBASE-SR Ethernet and CPRI/eCPRI standards. The transmission distance can be up to 70m (OM3) or 100m (OM4) through multi-mode optical fiber.