14.2.10a Reference sensitivity – TCH/AFS in TIGHTER configuration

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

14.2.10a.1 Definition

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

14.2.10a.2 Conformance requirement

3GPP TS 45.005 subclause 6.2.5

The reference performance for Tightened Link Level Performance (TIGHTER) specified in table 1w, shall be

For speech channels (TCH/FS, TCH/HS, TCH/EFS, TCH/AFSx, TCH/AHSx, TCH/WFSx ) FER:  1 %

In addition for speech channels the residual class Ib BER and residual class II BER performance shall not exceed the specified values in table 1w at the corresponding signal level in dBm. The reference sensitivity level in section 6.2.1 shall be applied for TIGHTER MS.

14.2.10a.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. For TCH AFS/FER, MS shall meet the reference sensitivity performance mentioned in 3GPP TS 45.005 sub clause 6.2.5, for reference sensitivity level mentioned in Table 1w according to propagation conditions.

2. For TCH/AFS class Ib RBER, MS shall meet the reference sensitivity performance mentioned in 3GPP TS 45.005 sub clause 6.2.5, for reference sensitivity level mentioned in Table 1w according to propagation conditions.

14.2.10a.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.

14.2.10a.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.

Specific PICS Statements:

14.2.10a.4.2 Procedure

a) The fading function is set to TUhigh no FH.

b) The SS sets the amplitude of the wanted signal to reference sensitivity as defined in Table 1w.

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

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

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

14.2.10a.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 14.2.10a.5-1: 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 14.2.10a.5-2 to 14.2.10a.5-3.

Table 14.2.10a.5-2 : Statistical test limits for 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 14.2.10a.5-3 : 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

0,020000

0,024680

13979

280

00:04:40

Class1b

12200

8150

0,014000

0,017276

19970

2

00:00:02

AFS 10.2

frames

10200

50

0,006500

0,008021

43012

860

00:14:20

Class1b

10200

6950

0,001200

0,001481

232982

34

00:00:34

AFS 7.4

frames

7400

50

0,000360

0,000444

776607

15532

04:18:52

Class1b

7400

4350

0,000130

0,000160

2150605

494

00:08:14