The 2100 MHz band can be used for NR (5G), LTE and UMTS and consists of 60 MHz each in the download and uplink, see the following figure:
The band ist divided among operators as follows (change end of 2020):
The previous allocation (expiring on December 31, 2020) is available here.
The band is called "Band 1" in UMTS and LTE, and "Band n1" in NR (5G). The original use for UMTS is increasingly being used by LTE
and NR (as "dynamic spectrum sharing", DSS).