Understanding 5G Beam Management

A key feature of the 5G-New Radio (NR) design is its ability to operate in two different frequency ranges: sub-6 GHz and millimeter wave (mmWave). As the availability of sub-6 GHz range becomes more limited, mmWave frequency bands with wider bandwidths will become more predominant. mmWave is a short-range, high-frequency wave operating above 24 GHz spectrum, which offers higher capacity.

Characteristics such as propagation loss, signal blockage, and fading effects differ from mmWave to the sub 6Ghz band, which introduces new challenges for the system design and affect the end-to-end throughput and quality of the user experience. Throughput is one of the key factors in making 5G successful.

To address these limitations, 3GPP 5G NR standards define new Physical Layer (PHY) and Medium Access Control (MAC) layer features to support directional communications. Among the important features is beam management, which is used to acquire and maintain beams. It also defines new initial access procedures to ensure successful directional transmission.