Huawei 5G phone limitations

Access stratum capabilities

Huawei mate X 20 / 30 / P40 registers in NSA mode with an accessStratumRelease rel13 instead of rel15 ( in the eutra UE capabilities)

To ignore this inconsistency and consider this device as a 4G/5G device, you can add the following field in the enb.cfg :

Example

/* list of cells */ cell_list: [ { rf_port: 0, /* Broadcasted PLMN identities */ plmn_list: [ "00101", ], dl_earfcn: 300, /* 2140 MHz, band 1 */ n_id_cell: 1, cell_id: 0x01, tac: 0x0001, root_sequence_index: 120, /* PRACH root sequence index */ ignore_ue_as_release: true, nr_scell_list: [ { cell_id: 0x02 } ], }, ], /* cell_list */

SCG Failure Information NR

When 5G NR bearer is added before measurement report b1 is triggered , the UE fails to detect the NR cell and finally returns a SCG Failure Information NR over LTE

To overcome this issue, it's recommended to trigger the NR bearer addition upon the measurement report NR B1 reception. To do that , add the measurement configuration in the enb.cfg file under the lte cell_default: field :

Example

/* measurement configuration */ meas_config_desc: { a1_report_type: "rsrp", a1_rsrp: -70, a1_hysteresis: 10, a1_time_to_trigger: 320, a2_report_type: "rsrp", a2_rsrp: -110, a2_hysteresis: 0, a2_time_to_trigger: 640, a3_report_type: "rsrp", a3_offset: 6, a3_hysteresis: 0, a3_time_to_trigger: 256, rsrp_filter_coeff: 3, nr_b1_report_type: "rsrp", nr_b1_rsrp: -119, nr_b1_hysteresis: 10, nr_b1_time_to_trigger: 480, nr_rsrp_filter_coeff: 3 }, meas_gap_config: "gp0", /* DRB configuration */ drb_config: "drb.cfg", },

SA mode

With this firmware

Model: EVR-N29 Build Number: 9.1.1.188(C431E2R4P1) GPU Turbo

we are able to successfully test SA mode with the Mate20X using a test sim card. If the phone gets locked after the first SA attach, try a factory reset.

The SA cell must be at least 40MHz with a sub carrier spacing of 30KHz.

Other firmwares seem to be restricting SA to a list of white listed PLMNs. Here is the information we gathered so far:

• for some versions you should use a SIM card to modify its IMSI with a Chinese PLMN 46011 and configure the gNB and AMF to use the same PLMN. Some other versions work fine with the 00101 test PLMN and a test SIM card
• Have the IMS server running because the phone will disconnect if it fails to perform its IMS registration. Some other customers reported that they could run without IMS server by ensuring that ims_vops MME configuration parameter is set to false.

Some other customers had less pain with the Huawei CPE WL2H112SM, but it still mandates the Chinese PLMN or test PLMN as far as we know.