Bandwidth part

Bandwidth part (BWP) is one of the most important concepts innovated in 5G NR, and it has a profound impact on almost all NR aspects such as resource allocation, uplink and downlink control channels, initial access, MIMO, MAC/RRC layer protocols, etc. Many BWP design problems were gradually solved in the course of standardization, including how to configure a BWP; the relationship between BWP configuration and numerology; whether the BWP configuration should be different between TDD and FDD systems; activation/deactivation mechanism for BWP; how to use BWP in the initial access process before RRC connection is established; and the relationship between BWP and carrier aggregation. This chapter explains the corresponding solutions one by one.