 of the supported band or band combinations. For LTE in the case of dual connectivity, the approximate data rate for a given number of aggregated carriers in a band or band combination is computed as DMR-DC = 10-3 =1 TBS} (Mbps), where J is the number of aggregated LTE component carriers in multi-radio dual connectivity (MR-DC) band combination and TBSj is the total maximum number of DL-SCH transport block bits received within a 1 ms TTI for the jth component carrier based on the UE supported maximum MIMO layers for the jth carrier, and based on the modulation order and the number of physical resource blocks (PRBs) in the bandwidth of the jth carrier. The approximate maximum data rate can be calculated as the maximum of the approximate data rates computed using the latter equation for each of the supported band or band combinations. For MR-DC, the approximate maximum data rate is computed as the sum of the approximate maximum data rates from NR and LTE [13]. The total layer 2 buffer size is another UE capability attribute that is defined as the sum of the number of bytes that the UE is capable of storing in the RLC transmission windows and RLC reception and reordering windows and also in PDCP reordering windows for all radio bearers. The total layer 2 buffer size in MR-DC and NR-DC scenario is the maximum of the calculated values based on the following equations [13]: MaxULDataRate_MNXRLCRTT_MN+MaxULDataRate_SNXRLCRTT_SN + MaxDLDataRate_SN RLCRTT_SN + MaxDLDataRate_MN X (RLCRTT_SN+X2/Xndelay + QueuinginSN) MaxULDataRate_MNXRLCRTT_MN+ MaxULDataRate_SN X RLCRTT_SN + MaxDLDataRate_MN> RLCRTT_MN + -MaxDLDataRate_SN (RLCRTT_MN + X2/Xndelay+QueuinginMN) In other scenarios, the total layer 2 buffer size is calculated as MaxDLDataRate X RLCRTT + MaxULDataRate X RLCRTT. It must be noted that the additional layer 2 buffer required for preprocessing of data is not taken into account in above formula. The total layer 2 buffer size is determined as the maximum layer 2 buffer size of all calculated ones for each band combinati