When you walk along the street or drive on the road, you will notice various communication base stations. Their main function is to facilitate wireless communication with mobile phones.

Communication base stations are equipped with base station antennas and radio frequency remote units (RFUs) designed to drive the antennas' operation. Typically, a 5G base station requires three antennas along with corresponding RFUs. Each antenna provides coverage for 120 degrees, allowing three antennas to achieve a 360-degree omnidirectional coverage. In traditional 5G base station construction, 25G white optical modules with a wavelength of 1310nm and optical fibers are used to connect the RFUs on the signal tower to the base station controller in the backend equipment room. Signal transmission between each RFU and the base station controller requires a pair of optical fibers, resulting in a total of three pairs of fibers, or six fiber cores, for the connection of three antennas/RFUs to the base station controller.

In the case of co-building 4G and 5G, following the traditional construction approach would necessitate 12 fiber cores. This situation leads to a shortage of optical fiber resources and significant wastage. Particularly during the initial phases of large-scale 5G deployment, the rapid completion of 5G base station construction and activation becomes a prevalent challenge in the face of limited optical fiber resources. In response to this scenario, a passive wavelength division multiplexing (WDM) based base station fronthaul construction solution has been proposed to address the effective utilization of optical fiber resources.

Sino-Telecom possesses extensive technical expertise and rich market experience in the field of wavelength division multiplexing (WDM), being one of the earliest companies in China to apply passive WDM technology to the domain of base station fronthaul. The fundamental principle of Sino-Telecom's 5G fronthaul solution, based on passive WDM, involves utilizing a wavelength division multiplexer to divide the optical fiber into six wavelength channels with 20nm intervals: 1270nm, 1290nm, 1310nm, 1330nm, 1350nm, and 1370nm. Simultaneously, the traditional 1310nm white light modules on the radio frequency remote units (RFUs) and base station controllers are replaced with corresponding colored light modules supporting the six different wavelengths.

By implementing this approach, the original requirement of six separate fibers for transmission between the base station and RFUs can be achieved through a single fiber utilizing the six wavelength channels. This results in the virtualization of one fiber into the equivalent of six fibers. Drawing an analogy to transportation, this can be likened to expanding a single lane into a bidirectional six-lane highway using wavelength division multiplexing technology, eliminating the need for constructing an additional five lanes. This approach significantly reduces optical fiber deployment costs and expedites the base station construction timeline.
Moreover, in the scenario of co-locating 4G and 5G infrastructure, the optical fiber can be expanded to incorporate twelve wavelength channels with 20nm intervals. In addition to the six wavelength channels dedicated to 5G base stations, the extra six wavelength channels are designated for 4G base station transmission at 1390nm, 1410nm, 1430nm, 1450nm, 1470nm, and 1490nm. It is noteworthy that the transmission speed of the optical modules in the 4G RFUs and base station controllers is 10Gbps. Drawing a parallel to transportation, this application scenario involves expanding a single lane into a bidirectional twelve-lane highway through wavelength division multiplexing technology.

Sino-Telecom's passive wavelength division multiplexing-based 5G fronthaul products have earned industry acclaim for their exceptional technical performance, adaptability to temperature variations, and ease of construction. These products play a crucial role in telecommunications operators' 5G network deployment, offering outstanding technical features and contributing significantly to cost reduction, efficiency improvement, and resource optimization. Sino-Telecom is recognized as a reliable partner, providing telecommunications operators with versatile, speedy, excellent, and cost-effective solutions, solidifying its reputation in the industry.