9 Immunity

37.1133GPPMulti-Standard Radio (MSR) Base Station (BS) Electromagnetic Compatibility (EMC)NR, E-UTRA, UTRA and GSM/EDGERelease 17TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

9.1 Test configurations

This subclause defines the configurations for immunity tests as follows:

– the equipment shall be tested under normal test conditions as specified in the functional standards;

– the test configuration shall be as close to normal intended use as possible;

– if the equipment is part of a system, or can be connected to ancillary equipment, then it shall be acceptable to test the equipment while connected to the minimum configuration of ancillary equipment necessary to exercise the ports;

– if the equipment has a large number of ports, then a sufficient number shall be selected to simulate actual operation conditions and to ensure that all the different types of termination are tested;

– the test conditions, test configuration and mode of operation shall be recorded in the test report;

– ports which in normal operation are connected shall be connected to an ancillary equipment or to a representative piece of cable correctly terminated to simulate the input/output characteristics of the ancillary equipment, Radio Frequency (RF) input/output ports shall be correctly terminated;

– ports which are not connected to cables during normal operation, e.g. service connectors, programming connectors, temporary connectors etc. shall not be connected to any cables for the purpose of EMC testing. Where cables have to be connected to these ports, or interconnecting cables have to be extended in length in order to exercise the EUT, precautions shall be taken to ensure that the evaluation of the EUT is not affected by the addition or extension of these cables;

– Immunity tests on the entire base station shall be performed by establishing communication links at the radio interface (e.g. with the mobile simulator) and the S1/Iub/ Abis interface (e.g. with an RNC/EPC/BSC simulator) and evaluating the BLER/throughput/BER (see Figure 9.1-1);

– Immunity tests shall be performed on both the Uplink and Downlink paths. The tests shall also include both the radio interface and the S1/Iub/ Abis interface. BLER/throughput/BER evaluation may be carried out at either interface, where appropriate, and the measurements for the Uplink and Downlink paths may be carried out as a single path looped at either the radio interface or S1/Iub/ Abis interface. In case of looping is used care have to be taken that the BLER/throughput/BER information doesn’t change due to looping.

– For BS capable of multi-RAT and/or multi-band operation, communication links shall be established in such a way that all RATs and operating band(s) are activated during the test according to the applicable test configurations in subclause 4.5. Performance assessment may be done separately for each RAT and/or operating band.

Figure 9.1-1: Communication link set up for BS immunity measurement

9.2 RF electromagnetic field (80 MHz – 6000 MHz)

The test shall be performed on a representative configuration of the equipment, the associated ancillary equipment, or representative configuration of the combination of radio and ancillary equipment.

9.2.1 Definition

This test assesses the ability of radio equipment and ancillary equipment to operate as intended in the presence of a radio frequency electromagnetic field disturbance at the enclosure.

9.2.2 Test method and level

The test method shall be in accordance with IEC 61000‑4‑3 [23]. The use of reverberation chamber test method according to IEC 61000-4-21 [40], clause 6.1 and Annex D as alternative method. is allowed:

– for transmitters, receivers and transceivers the following requirements shall apply:

– the test level shall be 3 V/m amplitude modulated to a depth of 80 % by a sinusoidal audio signal of 1 kHz;

– the stepped frequency increments shall be 1 % of the momentary frequency;

– the test shall be performed over the frequency range 80 MHz – 6000 MHz with the exception of the exclusion band for receivers (see subclause 4.4);

– responses in stand-alone receivers or receivers which are part of transceivers occurring at discrete frequencies which are narrow band responses, shall be disregarded, see subclause 4.3;

– the frequencies selected during the test shall be recorded in the test report.

9.2.3 Performance criteria

Base station:

The performance criteria of subclause 6.1 shall apply.

Ancillary equipment:

The performance criteria of subclause 6.3 shall apply.

9.3 Electrostatic discharge

The test shall be performed on a representative configuration of the radio equipment, the associated ancillary equipment, or representative configuration of the combination of radio and ancillary equipment.

9.3.1 Definition

This test assesses the ability of radio equipment and ancillary equipment to operate as intended in the event of an electrostatic discharge.

9.3.2 Test method and level

The test method shall be in accordance with IEC 61000‑4‑2 [24]:

– for contact discharge, the equipment shall pass at ±4 kV;

– for air discharge shall pass at ±8 kV;

– electrostatic discharge shall be applied to all exposed surfaces of the EUT except where the user documentation specially indicates a requirement for appropriate protective measures.

NOTE: Ensure that the EUT is fully discharged between each ESD exposure.

9.3.3 Performance criteria

Base station:

The performance criteria of subclause 6.2 shall apply.

Ancillary equipment:

The performance criteria of subclause 6.4 shall apply.

9.4 Fast transients common mode

The test shall be performed on AC mains power input ports.

This test shall be performed on signal ports, telecommunication ports, control ports and DC power input/output ports if the cables may be longer than 3 m.

Where this test is not carried out on a port or any other ports because the manufacturer declares that it is not intended to be used with cables longer than 3 m, a list of ports which were not tested for this reason shall be included in the test report.

This test shall be performed on a representative configuration of the equipment, the associated ancillary equipment, or representative configuration of the combination of radio and ancillary equipment.

9.4.1 Definition

This test assesses the ability of radio equipment and ancillary equipment to operate as intended in the event of fast transients present on one of the input/output ports.

9.4.2 Test method and level

The test method shall be in accordance with IEC 61000‑4‑4 [25]:

– the test level for signal ports, telecommunication ports and control ports shall be 0,5 kV open circuit voltage as given in IEC 61000‑4‑4 [25];

– the test level for DC power input/output ports shall be 0.5 kV open circuit voltage as given in IEC 61000‑4‑4 [25];

– the test level for AC mains power input ports shall be 1 kV open circuit voltage as given in IEC 61000‑4‑4 [25].

For AC and DC power input ports the transients shall be applied (in parallel) to all the conductors in the cable with reference to the cabinet reference earth (true common mode) and the source impedance shall be 50 Ω.

9.4.3 Performance criteria

Base station:

The performance criteria of subclause 6.2 shall apply.

Ancillary equipment:

The performance criteria of subclause 6.4 shall apply.

9.5 RF common mode (0,15 MHz – 80 MHz)

The test shall be performed on AC mains power input/output ports.

This test shall be performed on signal ports, telecommunication ports, control and DC power input/output ports, which may have cables longer than 3 m.

Where this test is not carried out on a port or any other ports because the manufacturer declares that it is not intended to be used with cables longer than stated above, a list of ports which were not tested shall be included in the test report.

NOTE: This test can also be performed using the intrusive method, where appropriate, see IEC 61000‑4‑6 [26].

9.5.1 Definition

This test assesses the ability of radio equipment and ancillary equipment to operate as intended in the presence of a radio frequency electromagnetic disturbance.

9.5.2 Test method and level

The test method shall be in accordance with IEC 61000‑4‑6 [26]:

– the test signal shall be amplitude modulated to a depth of 80 % by a sinusoidal audio signal of 1 kHz;

– the stepped frequency increments shall be 50 kHz in the frequency range 150 kHz to 5 MHz and 1% frequency increment of the momentary frequency in the frequency range 5 MHz to 80 MHz;

– the test level shall be severity level 2 as given in IEC 61000‑4‑6 [26] corresponding to 3 V rms, at a transfer impedance of 150 Ω;

– the test shall be performed over the frequency range 150 kHz – 80 MHz;

– the injection method to be used shall be selected according to the basic standard IEC 61000-4-6 [26];

– responses of stand-alone receivers or receivers which are part of transceivers occurring at discrete frequencies which are narrow band responses, shall be disregarded, see subclause 4.3;

– the frequencies of the immunity test signal selected and used during the test shall be recorded in the test report.

9.5.3 Performance criteria

Base station:

The performance criteria of subclause 6.1 shall apply.

Ancillary equipment:

The performance criteria of subclause 6.3 shall apply.

9.6 Voltage dips and interruptions

The tests shall be performed on AC mains power input ports.

These tests shall be performed on a representative configuration of the equipment, the associated ancillary equipment, or representative configuration of the combination of radio and ancillary equipment.

9.6.1 Definition

These tests assess the ability of radio equipment and ancillary equipment to operate as intended in the event of voltage dips and interruptions present on the AC mains power input ports.

9.6.2 Test method and level

The test method shall be in accordance with IEC 61000‑4‑11 [27], wherethe test levels shall be:

– Voltage dip: 0 % residual voltage for 0.5 cycle;

– Voltage dip: 0 % residual voltage for 1 cycle;

– Voltage dip: 70 % residual voltage for 25/30 cycles (at 50/60 Hz);

– Voltage interruption: 0 % residual voltage for 250/300 cycles (at 50/60 Hz).

9.6.3 Performance criteria

For a 0 % residual voltage dip test, the performance criteria for transient phenomena shall be applied:

– Criteria 6.2 for base station

– Criteria 6.4 for ancillary equipment

For a 70% residual voltage dip test and for voltage interruption test, the following applies:

1. In the case where the equipment is fitted with or connected to a battery back-up, the following performance criteria shall be applied:

– Criteria 6.2 for base station

– Criteria 6.4 for ancillary equipment

2. In the case where the equipment is powered solely from the AC mains supply (without the use of a parallel battery back-up) volatile user data may have been lost and if applicable the communication link need not to be maintained and lost functions should be recoverable by user or operator:

– No unintentional responses shall occur at the end of the test, when the voltage is restored to nominal

– In the event of loss of communications link or in the event of loss of user data, this fact shall be recorded in the test report

9.7 Surges, common and differential mode

The tests shall be performed on AC mains power input ports.

This test shall be additionally performed on telecommunication ports.

9.7.1 Definition

These tests assess the ability of radio equipment and ancillary equipment to operate as intended in the event of surges being present at the AC mains power input ports and telecommunication ports.

9.7.2 Test method and level

The test method shall be in accordance with IEC 61000-4-5 [28].

The requirements and evaluation of test results given in subclause 9.7.2.1 (telecommunication ports, outdoor cables), subclause 9.7.2.2 (telecommunication ports, indoor cables) and subclause 9.7.2.3 (AC power ports) shall apply, but no test shall be required where normal functioning cannot be achieved, because of the impact of the CDN on the EUT.

9.7.2.1 Test method for telecommunication ports directly connected to outdoor cables

The test level for telecommunications ports, intended to be directly connected to the telecommunications network via outdoor cables, shall be 1 kV line to ground as given in IEC 61000-4-5 [28]. In this case the total output impedance of the surge generator shall be in accordance with the basic standard IEC 61000-4-5 [28].

The test generator shall provide the 1,2/50 μs pulse as defined in IEC 61000-4-5 [28].

9.7.2.2 Test method for telecommunication ports connected to indoor cables

The test level for telecommunication ports, intended to be connected to indoor cables (longer than 10 m) shall be 0,5 kV line to ground. In this case the total output impedance of the surge generator shall be in accordance with the basic standard IEC 61000-4-5 [28].

The test generator shall provide the 1,2/50 μs pulse as defined in IEC 61000-4-5 [28].

9.7.2.3 Test method for AC power ports

The test level for AC power input ports shall be 2 kV line to ground, and 1 kV line to line, with the output impedance of the surge generator as given in IEC 61000-4-5 [28].

In telecommunication centres 1 kV line to ground and 0,5 kV line to line shall be used.

The test generator shall provide the 1,2/50 μs pulse as defined in IEC 61000-4-5 [28].

9.7.3 Performance criteria

Base station:

The performance criteria of subclause 6.2 shall apply.

Ancillary equipment:

The performance criteria of subclause 6.4 shall apply.

Annex A (normative):
BER assessment for GSM/EDGE