14.2.23 Reference sensitivity – O-TCH/WHS

3GPP51.010-1Mobile Station (MS) conformance specificationPart 1: Conformance specificationTS

14.2.23.1 Definition

14.2.23.2 Conformance requirement

For 8-PSK modulated speech channels for AMR, associated control channels and inband signalling, the minimum input signal level for which the reference performance shall be met is specified in table 1g

For all classes of MS supporting 8-PSK speech channels, an additional +2 dB adjustment applies for 8-PSK modulated speech channels.

The reference performance shall be:

For speech channels (O-TCH/WHSy) FER £ 1%

All other requirements in tables 1f and 1g shall be fulfilled at this input level for reference performance.

Correction values for 8-PSK modulated signals:

for GSM 400, GSM 900, GSM 850, T-GSM 810 and GSM 700 small MS

0 dB

for other GSM 400, GSM 900, GSM 850, T-GSM 810 and GSM 700 MS

-2 dB

for DCS 1 800 and PCS 1900 class 1 or class 2 MS

0 dB

for other DCS 1 800 and PCS 1900 MS

-2 dB

3GPP TS 45.005, subclause 6.2.

14.2.23.3 Test purpose

To verify that the MS does not exceed conformance requirement for FER and class 1b RBER under HT100 propagation conditions with an allowance for the statistical significance of the test, for channel combinations O-TCH/WHS12.65 and O-TCH/WHS 8.85.

14.2.23.4 Method of test

14.2.23.4.1 Initial conditions

A call is set up according to the generic call set up procedure on a O-TCH/WHS with an ARFCN in the mid ARFCN range, power control level set to maximum power. RADIO_LINK_TIMEOUT is set to maximum.

The multirate configuration indicates the use of a codec set limited to 12,65 kbit/s.

The SS transmits Standard Test Signal C1 on the traffic channel (wanted signal).

The SS commands the MS to create the traffic channel loop back, signalling erased frames (subclause 36).

14.2.23.4.2 Procedure

a) The fading function is set to HT100.

b) The SS sets the level of the wanted signal to that indicated by Clev in table 14.2.23-2 or 14.2.23-3. The level is corrected by the appropriate value in the table above.

c) The SS compares the data of the signal that it sends to the MS with the signal which is looped back from the receiver after demodulation and decoding, and checks the frame erasure indication.

d) The SS determines the number of residual bit error events for the bits of the class Ib, by examining sequences of at least the minimum number of samples of consecutive bits of class Ib. Bits are only taken from those frames not signalled as erased.

e) The SS also determines the frame erasure events by examining sequences of at least the minimum number of samples of consecutive frames and assuming a frame is received successfully, if it is not signalled as erased.

f) The SS uses a Channel Mode Modify procedure to change the active codec set to 8.85 kbit/s and steps b) to e) are repeated.

Maximum/Minimum Duration of Test

Maximum: 19 minutes (GSM850), 19 minutes (GSM900), 19 minutes (DCS1800), 19 minutes (PCS1900).

Minimum: 7 minutes (GSM850), 7 minutes (GSM900), 3 minutes (DCS1800), 3 minutes (PCS1900).

14.2.23.5 Test requirements

Testing should be performed using statistical methods that lead to an early pass/fail decision with test time significantly reduced for MS with FER/BER not on the limit.

For more information on statistical testing of BER/BLER performance, especially the definition of limit lines refer to Annex 7.

Wrong decision risk F for one single error rate test:

Fpass   =   Ffail   =   F and F   =   0.2%

Wrong decision probability D per test step:

Dpass   =   Dfail   =   D and D   =   0.0085%

Parameters for limit lines:

1. D =  0.000085 wrong decision probability per test step.

2. M =   1.5 bad DUT factor

3. ne number of (error) events. This parameter is the x‑ordinate in figure A7.1.3.1.

4. ns number of samples. The error rate is calculated from ne and ns.

Limit checking

Before limit checking is valid the minimum test time due to fading needs to be considered:

Testing under multipath and interference conditions requires that at least 990 wavelengths are crossed with the speed given in the fading profile. This leads to a minimum test time depending on the frequency range. No early pass/fail decision is allowed until the minimum test time due to fading has elapsed.

Table 14.2.23-1: Minimum test times due to HT 100 fading conditions

Half Rate 100 km/h

Frequency (GHz)

0,85

0,9

1,8

1,9

Wavelength (m)

0,35

0,33

0,17

0,16

min test time (s)

201

190

95

90

0:03:21

0:03:10

0:01:35

0:01:30

If the minimum test time due to multipath conditions exceeds the target test time, then the test runs for the minimum test time due to multipath conditions and the decision is made by comparing the result with the “derived test limit”. In this case early pass/fail decisions are obsolete.

If the target test time exceeds the minimum test time due to multipath conditions early pass/fail decisions can be headed for in order to accelerate test execution.

For an early decision a minimum number of (error) events is necessary.

For an early pass decision ne   ≥   1 (inclusive artificial error)

For an early fail decision ne   ≥   7

When the target test time has been reached the test is finished and a pass/fail decision can be made.

The error rate measured in this test shall be tested according to the values given in tables 14.2.23-2 and 14.2.23.3

Table 14.2.23-2: Statistical test limits for GSM 850 and GSM 900 O-TCH/WHS reference sensitivity

HT100 / No FH

0.8 to 0.9GHz

Clev (dBm)

Samples per second

Orig. BER requirement

Derived test limit

Target number of samples

Target test time (s)

Target test time (hh:mm:ss)

WHS12.65

Frames

-90.5

50

0,010000

0,012340

27958

560

00:09:20

Class1b

9050

0,004000

0.004936

69895

8

00:00:08

WHS 8.85

Frames

-92.0

50

0,010000

0,012340

27958

560

00:09:20

Class1b

5650

0,001300

0.001604

215087

38

00:00:38

Table 14.2.23-3: Statistical test limits for DCS 1 800 and PCS 1 900 O-TCH/WHS reference sensitivity

HT100 / No FH

1.8 to 1.9GHz

Clev (dBm)

Samples per second

Orig. BER requirement

Derived test limit

Target number of samples

Target test time (s)

Target test time (hh:mm:ss)

WHS12.65

Frames

-90.0

50

0,010000

0,012340

27958

560

00:09:20

Class1b

9050

0,004400

0.005430

63536

7

00:00:07

WHS 8.85

Frames

-92.0

50

0,010000

0,012340

27958

560

00:09:20

Class1b

5650

0,001500

0.001851

186386

33

00:00:33