14.2.10 Reference sensitivity – TCH/AFS

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

14.2.10.1 Definition

The reference sensitivity is the signal level at the MS receiver input at which a certain BER and FER must be achieved.

For E-GSM 900 MS this test is only performed in the P-GSM band.

14.2.10.2 Conformance requirement

1. At reference sensitivity level, the TCH/AFS FER shall meet the reference sensitivity performance of table 1 in 3GPP TS 05.05 subclause 6.2.

2. At reference sensitivity level, the TCH/AFS class Ib RBER shall meet the reference sensitivity, performance of table 1 in 3GPP TS 05.05 subclause 6.2.

14.2.10.3 Test purpose

NOTE: This test is not performed under STATIC propagation conditions because the performance requirements are too small to be accurately measured.

1. To verify that the MS does not exceed conformance requirement 1 under TUhigh propagation conditions with an allowance for the statistical significance of the test.

2. To verify that the MS does not exceed conformance requirement 2 under TUhigh propagation conditions with an allowance for the statistical significance of the test.

14.2.10.4 Method of test

NOTE 1: The BA list sent on the BCCH and SACCH will indicate at least six surrounding cells with at least one near to each band edge. It is not necessary to generate any of these BCCHs but, if provided the signal strengths of BCCHs shall be in the range 15 dBVemf(  ) to 35 dBVemf(  ).

NOTE 2: The ARFCN of any BCCH shall not be co-channel or on adjacent channels to the wanted traffic channel.

NOTE 3: When frequency hopping is used, the traffic channel may fall on any of the ARFCNs defined in clause 6.

14.2.10.4.1 Initial conditions

A call is set up according to the generic call set up procedure on a TCH/AFS with an ARFCN in the Mid ARFCN range for GSM 400, GSM 700, T-GSM 810, GSM 850, DCS 1800 and PCS 1 900 and ARFCN 70 for GSM 900, power control level set to maximum power.

NOTE: For GSM 900 ARFCN 70 is tested since this is the 73rd harmonic of the 13 MHz clock normally used internally in a MS.

The multirate configuration indicates the use of a codec set limited to 12,2 kbit/s.

The SS transmits Standard Test Signal C1 on the traffic channel.

The SS commands the MS to create traffic channel loop back signalling erased frames.

14.2.10.4.2 Procedure

a) The fading function is set to TUhigh.

b) the SS sets the amplitude of the wanted signal to reference sensitivity level ( ).

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 class Ib, by examining sequences of at least the minimum number of samples of consecutive bits of class Ib. Bits are taken only 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 10,2 kbit/s and steps a) to e) are repeated.

g) The SS uses a Channel Mode Modify procedure to change the active codec set to 7,4 kbit/s and steps a) to e) are repeated.

Maximum/Minimum Duration of Test

Statistical test method, pre Rel-5 MS

Maximum: 31 minutes (GSM850, GSM900), 83 minutes (DCS1800, PCS1900).

Minimum: 10 minutes (GSM850, GSM900), 5 minutes (DCS1800, PCS1900).

Statistical test method, Rel-5 onwards MS

Maximum: 31 minutes (GSM850, GSM900), 278 minutes (DCS1800, PCS1900).

Minimum: 10 minutes (GSM850, GSM900), 9 minutes (DCS1800, PCS1900).

14.2.10.5 Test requirements

Testing the reference sensitivity performance is performed using statistical methods that lead to an early pass/fail decision with test time significantly reduced for MS with BER/BLER not on the limit.

For more information on statistical testing of BER/BLER performance, especially the definition of the limit lines refer to Annex 6.2

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.

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. No early pass/fail decision is allowed until the minimum test time due to fading has elapsed.

Table 14-36: Minimum test times due to TU high fading conditions

Full Rate 50 km/h

Frequency

0,4

0,7

0,85

0,9

1,8

1,9

GHz

Wavelength

0,75

0,43

0,35

0,33

0,17

0,16

m

min test time

428

244

201

190

95

90

s

0:07:08

0:04:04

0:03:21

0:03:10

0:01:35

0:01:30

hh:mm:ss

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 done 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 rates measured for different channels and under the different propagation conditions, shall be tested according to the values given in table 14-37 or 14-38.

Table 14-37: Statistical test limits for GSM 400, GSM 700, T-GSM 810, GSM 850 and GSM 900 sensitivity

TU high no FH

0.4 to 0.9GHz

frames per s

Orig. BER

Derived

Target number

Target test

Target test time

Channel

bits per sec

clas1b per s

requirement

test limit

of samples

time (s)

(hh:mm:ss)

AFS 12.2

frames

12200

50

0,049000

0,060466

5706

114

00:01:54

Class1b

12200

8150

0,015000

0,018510

18639

2

00:00:02

AFS 10.2

frames

10200

50

0,021000

0,025914

13313

266

00:04:26

Class1b

10200

6950

0,002300

0,002838

121556

17

00:00:17

AFS 7.4

frames

7400

50

0,004100

0,005059

68190

1364

00:22:44

Class1b

7400

4350

0,000540

0,000666

517738

119

00:01:59

Table 14-38: Statistical test limits for DCS 1 800 and PCS 1 900 sensitivity

TU high no FH

1.8 to 1.9 GHz

frames per s

Orig. BER

Derived

Target number

Target test

Target test time

Channel

bits per sec

clas1b per s

requirement

test limit

of samples

time (s)

(hh:mm:ss)

AFS 12.2

frames

12200

50

Pre Rel-5:

0,030000

Rel-5:

0,020000

Pre Rel-5:

0,037020

Rel-5:

0,024680

Pre Rel-5:

9320

Rel-5:

13979

Pre Rel-5:

186

Rel-5:

280

Pre Rel-5:

00:03:06

Rel-5:

00:04:40

Class1b

12200

8150

Pre Rel-5:

0,0150000

Rel-5:

0,014000

Pre Rel-5:

0,018510

Rel-5:

0,017276

Pre Rel-5:

18639

Rel-5:

19970

Pre Rel-5:

2

Rel-5:

2

Pre Rel-5:

00:00:02

Rel-5:

00:00:02

AFS 10.2

frames

10200

50

Pre Rel-5:

0,012000

Rel-5:

0,006500

Pre Rel-5:

0,014808

Rel-5:

0,008021

Pre Rel-5:

23299

Rel-5:

43012

Pre Rel-5:

466

Rel-5:

860

Pre Rel-5:

00:07:46

Rel-5:

00:14:20

Class1b

10200

6950

Pre Rel-5:

0,001700

Rel-5:

0,001200

Pre Rel-5:

0,002098

Rel-5:

0,001481

Pre Rel-5:

164458

Rel-5:

232982

Pre Rel-5:

24

Rel-5:

34

Pre Rel-5:

00:00:24

Rel-5:

00:00:34

AFS 7.4

frames

7400

50

Pre Rel-5:

0,001300

Rel-5:

0,000360

Pre Rel-5:

0,001604

Rel-5:

0,000444

Pre Rel-5:

215061

Rel-5:

776607

Pre Rel-5:

4301

Rel-5:

15532

Pre Rel-5:

01:11:41

Rel-5:

04:18:52

Class1b

7400

4350

Pre Rel-5:

0,000260

Rel-5:

0,000130

Pre Rel-5:

0,000321

Rel-5:

0,000160

Pre Rel-5:

1075302

Rel-5:

2150605

Pre Rel-5:

247

Rel-5:

494

Pre Rel-5:

00:04:07

Rel-5:

00:08:14