Building the base station power supply

This is when the PSU is no longer powering the PA, which is the main power draw, but still needs to power other electronics. The current target for low-load efficiency is about 30 W. Some OEMs would like to see that drop to nearly 10 W.

A power supply with a capacity of 100 W to 350 W was sufficient to cover many applications. Forward converters were a good choice and have been employed for years in telecom BBUs and RRUs. With the growing demand for mobile data, new markets and applications continue to emerge.

In practice, the battery groups (either traditional lead-acid batteries or emerging lithium ones) are deployed as the backup power supply of BSs. In our scenario, one battery group could be shared by multiple BSs nearby to exploit the statistical multiplexing gain, and the multiple BSs sharing the same battery group form a virtual cell (VC).

A simplified diagram of a typical telecommunications DC power system. When power from the grid is lost, the diesel generator is designed to start automatically providing AC power to the DC port system. The ATS synchronizes voltages from different sources to the equipment.

During quiescent periods—typically 5 ms to 100 ms—the PSU must minimize all load power with the basic functions of the antenna unit remaining active. It also must be able to ramp up to full power whenever the antenna wants to check for any active users within its range.

Therefore, BS power backup is in great need to keep the reliability of future mobile networks, especially for the macro BSs with large areas of network coverage and small ones serving mission-critical mobile and edge services (e.g., connected and automated vehicles ).