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Enable 2xNR-CA on X53, X60, X65 modems with MPSS.HI.4.0, MPSS.DE.1.0 baseband firmware or newer:

Qualcomm modems broadcast a packet called 0xB826 which contains NR-CA combos defined by the modem firmware. Said combos cannot be changed after compile time as they are defined in the .c,.cpp source of the modem firmware and is proprietary. However, the HW combos can be limited or ‘pruned’ by the OEM via NV item files i.e. cap_prune (Samsung only, reduces specific combos), cap_control_nrca_f_plus_t_band_combos (disables or enables FDD + TDD combos entirely). Specific bands (and hence all of their combos) can also be limited by excluding them from the policy files hardware_band_filtering.xml or carrier_policy.xml in the EFS.

Commercial support by a UE for NR-CA combos therefore can only confirmed by the contents of the ueCapabilityInformation RRC packet reponse to the network per the 3GPP Rel-15 standard, not soley the content of the 0xB826 packet as the OEM may have chose to limit or reduce the available NR-CA combinations (often per the carriers’ request). The information element we’re looking for is in the ueCapabilityInformation RRC packet and is called the BandCombinationList information element; which contains a list of NR-CA and/or EN-DC band combinations. In the absence of the appropriate NV item files, the NR-CA combos won’t be included in the UE’s response to the UE capability inquiry even if those bands are supported in HW. Once enabled via the NV item files, any NR-CA combos (NR-SA/NSA) supported in HW by the device will show in the NR ueCapabilityInformation RRC packet.

In addition to this guide for 2xNR-CA, there are two additional guides for adding 3xNR-CA in FDD+FDD+FDD here and TDD+FDD+FDD here.

Confirmed working with the following devices:

Devices with NR-CA enabled out of the box by the OEM:

Note: NR-CA in SA only mode excludes NR-CA in EN-DC e.g. n41-n71 but not 2-66_n41-n71

How to enable NR-CA in NR-SA and in NR-NSA (EN-DC/MR-DC)

Step 1: Launch EFS explorer

Launch QPST with your device in diag mode. Then, open the EFS explorer.

Step 2: Upload the NV item files for NR-CA

Navigate to /nv/item_files/modem/nr5g/RRC/

Right click and “Copy item file from PC”, do not drag or drop.

List of NV item files:

cap_control_mrdc_f_plus_t_band_combos set to 0x01, defines NR-NSA 2xDLCA FDD+TDD

cap_control_mrdc_t_plus_t_band_combos set to 0x010101, defines NR-NSA 2xDLCA TDD+TDD (intraband contiguous), TDD+TDD (intraband non-contigous), TDD+TDD (interband)

cap_control_nrca_f_plus_t_band_combos set to 0x01, defines NR-SA 2xDLCA FDD+TDD

cap_control_nrca_t_plus_t_band_combos set to 0x010101, defines NR-SA 2xDLCA TDD+TDD (intraband contiguous), TDD+TDD (intraband non-contigous), TDD+TDD (interband)

cap_control_nr_t_plus_t_band_combos set to 0x01, defines a booloean to enable DLCA TDD+TDD NSA NR-CA in SSIM, 0x0101 to enable in MSIM (>MPSS.HI.4.0), seems deprecated on >MPSS.DE.1.0

cap_control_t_plus_f_band_combos set to 0x0F, (bits 00001111), defines a global boolean switch for enabling TDD+FDD NR-CA in both NR-NSA and NR-SA on SSIM and MSIM configurations. Bits 1 & 2 define NR-CA MR-DC and NR-SA respectively, and bits 3 & 4 define MSIM and SSIM respectively. Set to 0x0D to limit to SSIM (0x05 is the default on Samsung UEs)

For dual SIM devices, also copy over the files suffixed by _Subscription01

Download from here