6.4 Transmitted RF carrier power versus time

3GPP51.021Base Station System (BSS) equipment specificationRadio aspectsRelease 17TS

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

6.4.1 Test purpose

To verify:

1) the time during which the transmitted power envelope should be stable (the useful part of the time slot);

2) the stability limits;

3) the maximum output power when nominally off between time slots.

It is not the purpose of this test to measure the detail of the power ramps; this is measured as adjacent channel power in subclause 6.5.

6.4.2 Test case

The Manufacturer shall declare how many TRXs the BSS supports, and declare any TRXs which are a dedicated BCCH carrier:

1 TRX: The BSS shall not be tested.

2 TRX: One TRX shall be configured to support the BCCH and the other shall be tested. Tests shall be performed on B, M and T, and both TRXs shall be tested on at least one frequency.

3 TRX: One TRX shall be configured to support the BCCH and the other two shall be tested at B, T and B, M. Tests shall be performed on B, M and T and both TRXs shall be tested on at least one frequency.

4 TRX or more: One TRX shall be configured to support the BCCH and three TRXs tested, one on B, one on M and one on T.

If the Manufacturer declares that Synthesizer Slow Frequency Hopping is supported by the BSS, the BSS shall be configured with the number of TRXs activated and frequency allocation defined above and SFH enabled. The TRX configured to support the BCCH shall not be tested.

If the TRX under test supports 8-PSK and/or other modulation(s), the test shall be performed at GMSK, 8-PSK and all other supported modulations.

A single time slot in a TDMA‑frame shall be activated in all TRXs to be tested, all other time slots in the TDMA‑frame shall be at Pidle.

Power measurements are made with a detector bandwidth of at least 300 kHz at the BTS antenna connector, at each frequency tested. Timing is related to T0 which, for the normal symbol rate case, is the transition time from symbol 13 to symbol 14 of the midamble training sequence for each time slot. For higher symbol rate T0 is defined as center of the 16^th symbol. For timing on a per time slot basis each time slot, for the normal symbol rate case, may contain 156.25 modulating symbols, or 2 time slots may contain 157 and 6 time slots 156 modulating symbols according to 3GPP TS 45.010. In case of higher symbol rate each time slot may contain 187,5 symbols or 188,4 symbols on timeslot 0 and 4 and 187,2 symbols on the remaining timeslots in a TDMA-frame. Measurements shall be made at Pmax and Pmin. The time slots measured shall be displayed or stored for at least 100 complete cycles of the time slot power sequence for each measurement.

Pmax = Power measured in subclause 6.3 (Highest Static Power Control Level).

Pmin = the Lowest Static Power Level measured in subclause 6.3.

Pidle Pmax ‑30 dB, or Pmin ‑ 30 dB.

As a minimum, one time slot shall be tested on each TRX under test which is not a dedicated BCCH.

6.4.3 Void

6.4.4 Conformance requirement

Test Environment

Normal

Minimum requirement

The output power of each GMSK modulated time slot tested relative to time shall conform with that illustrated in figure 6.4-1 and, if other modulations than GMSK are supported, in figures 6.4-2, 6.4-3, 6.4-4, 6.4-5 and 6.4-6. The residual output power, if a time slot is not activated, shall be maintained at, or below, the level of ‑30 dBc (300 kHz measurement bandwidth).

Power/time mask for GSM 400, GSM 900, ER-GSM 900, DCS 1800, GSM 700, GSM 850 and MXM 850

Power/time mask for PCS 1900 and MXM 1900

NOTE: The 0 dB reference is equal to the power Pmax or Pmin.

Figure 6.4-1: Power/time mask for power ramping of normal bursts at GMSK modulation

NOTE: The 0 dB reference is equal to the power Pmax or Pmin.

Figure 6.4-2: Power/time mask for power ramping of normal bursts at 8-PSK modulation

Figure 6.4-3: Power/Time mask for normal bursts (NB) at 16-QAM and 32-QAM modulation at normal symbol rate

Figure 6.4-4: Power/Time mask for higher symbol rate bursts (HB) at QPSK modulation with narrow pulse shaping filter

Figure 6.4-5: Power/Time mask for higher symbol rate bursts (HB) at 16-QAM and 32-QAM modulation with narrow pulse shaping filter

Figure 6.4-6: Power/time mask for power ramping of normal bursts at AQPSK modulation

(*)	For all BTS on all frequency bands	no requirement below ‑30 dBc
(****)	For all BTS on all frequency bands	Lower limit within the useful part of burst is seen as undefined for 16-QAM and 32-QAM.

6.4.5 Requirement reference

3GPP TS 45.005 subclause 4.5.1.