This spectrum as assigned in the multiband auction 700/1500/2100 MHz in 2020. In the year 2021 the usage rights were adjusted in accordance with changed Union law (Implementing Decision (EU) 2020/667).
The 2100 MHz band is currently used for 5G (NR band n1) and 4G (LTE band 1) and decreasingly for 3G (UMTS, band 1). The band is operated in frequency duplex (FDD), it consists of 60 MHz in the download and uplink, see the following figure:
Following the mulitband auction 700/1500/2100 MHz the band ist devided among operators as follows:
Historic information regarding the allocation following the procedure of the year 2000 is available here.