Non-signaling mode

In the non-signaling mode, continuous TX or RX mode and burst mode TX can be used.

When using continuous TX, closed-loop power control is not active. This may cause TX power to drift. Drift may happen with long TX transmissions using over 10 dBm power levels. To correctly decode the non-signaling mode TX signal, the RF tester must be set according to the system bandwidth defined in the %XRFTEST TX test command.

The non-signaling RX mode uses Carrier Wave (CW) signal for Signal-to-Noise Ratio (SNR) measurement and returns SNR and RSSI values for each measured frequency point.

The non-signaling mode SNR result can be converted to approximate sensitivity with the following formula:

Sensitivity [dBm] = Prx_snr [dBm] + BB_snr [dB] - SNR_result [dB]


CW level from signal generator [dBm]. The power level should be -90 dBm or less at the antenna feed pad.
Required minimum SNR to reach 5% block error rate (BLER). For LTE-M, 0.5 dB can be used, and for Narrowband Internet of Things (NB-IoT), 1.5 dB can be used.
SNR measurement result [dB]
Note: AFC correction should be performed to increase the accuracy of the RX SNR measurement. AFC correction can reduce the frequency error between nRF9160 and the used test equipment.

In the non-signaling mode, an RSSI scan test can be used to detect if noise from other sources, such as Integrated Circuit (IC)s or LEDs, is coupling to the LTE antenna RF path on the Printed Circuit Board (PCB). The test is a similar sweep as a non-signaling receiver sensitivity SNR test but without a CW test signal from an external signal generator. The level of the test signal in the XRFTEST AT command should be set to -90 dBm to set the RX gain properly.

The XRFTEST parameters used in the non-signaling mode tests are defined in Production test features in nRF91 AT Commands Reference Guide.