14.2.24 Reference sensitivity – TCH/WFS

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

14.2.24.1 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.

14.2.24.2 Conformance requirement

At reference sensitivity level, the TCH/WFS class Ib RBER shall meet the reference sensitivity, performance of table 1f in 3GPP TS 45.005 subclause 6.2.

At reference sensitivity level ,the TCH/WFS FER shall meet the reference performance stated in 3GPP TS 45.005 subclause 6.2.

The reference performance shall be:

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

The levels shall be corrected by the following values:

MS, GMSK modulated signals

for DCS 1 800 class 1 or class 2 MS

+2/+4 dB**

for DCS 1 800 class 3 MS

+2 dB

for GSM 400, GSM 900, GSM 850, T_GSM 810 and GSM 700 small MS

+2 dB

for other GSM 400, GSM 900, GSM 850, T_GSM 810 and GSM 700 MS

0 dB

for PCS 1900 class 1 or class 2 MS

+2 dB

for other PCS 1900 MS

0 dB

** For DCS 1 800 class 1 and class 2 MS, a correction offset of +2dB shall apply for the reference sensitivity performance as specified in table 1a for the normal conditions defined in Annex D and an offset of +4 dB shall be used to determine all other MS performances.

The performance requirements for GSM 400 and GSM 700 systems are as for GSM 900 in table 1f, except that the GSM 400 MS speed is doubled from that of GSM 900, e.g. TU50 becomes TU100, and the GSM 700 MS speed is increased by a factor of 1.2, e.g. TU50 becomes TU60.

3GPP TS 45.005 subclause 6.2

For T-GSM 810 the requirements for GSM 900 shall apply, apart for those parameters for which a separate requirement exists.

3GPP TS 45.005 subclause 2

14.2.24.3 Test purpose

1. To verify that the MS does not exceed conformance requirement at the maximum implemented codec rate under propagation condition TUhigh (for GSM700, T-GSM 810, GSM 850, GSM 900, DCS 1800 and PCS 1900) with no frequency hopping, RAhigh with no frequency hoping (for GSM700, T-GSM 810, GSM 850 and GSM 900), HThigh with no frequency hoping (for GSM700, T-GSM 810, GSM 850,GSM 900, DCS1800 and PCS 1900), and STATIC (for GSM700, T-GSM 810, GSM 850 and GSM900) with no frequency hopping with an allowance for the statistical significance of the test.

2. To verify that the MS does not exceed conformance requirement for the remaining implemented codec rates under propagation condition TUhigh with no frequency hopping with an allowance for the statistical significance of the test.

14.2.24.4 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.

14.2.24.4.1 Initial conditions

A call is set up according to the generic call set up procedure on a TCH/WFS with an ARFCN in the Mid ARFCN range for GSM700, 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 6.60 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.

14.2.24.4.2 Procedure

a) The fading function is set to TUhigh.

b) the SS sets the amplitude of the wanted signal to reference sensitivity level from table 2f in TS 45.005 based on the current active codec set, fading function of the SS and band. The level shall be corrected by the value in the table above describing the reference performance level correction factors for packet switched channels.

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 8.85 kbit/s and steps b) to e) are repeated.

g) The SS uses a Channel Mode Modify procedure to change the active codec set to 12.65 kbit/s and steps b) to e) are repeated.

h) The fading function is set to HThigh and steps b) to e) are repeated.

i) If DCS 1800 or PCS 1900 then skip steps j) and k).

j) The fading function is set to RAhigh and steps b) to e) are repeated.

k) The fading function is set to STATIC and steps b) to e) are repeated.

Maximum/Minimum Duration of Test

– Maximum: 15 minutes (GSM700, GSM850, GSM900) or 10 minutes ( DCS1800, PCS1900).

– Minimum: 15 minutes (GSM700, GSM850, GSM900) or 10 minutes (DCS1800, PCS1900).

14.2.24.5 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 14.2.24-1: 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

Full Rate 60 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

356

204

168

158

79

75

s

0:05:56

0:03:24

0:02:48

0:02:38

0:01:19

0:01:15

hh:mm:ss

Table 14.2.24-2: Minimum test times due to RA high fading conditions

Full Rate 250 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

m

min test time

86

49

40

38

S

0:1:26

0:0:49

0:0:40

0:0:38

hh:mm:ss

Full Rate 300 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

m

min test time

71

41

34

32

S

0:1:11

0:0:41

0:0:34

0:0:32

hh:mm:ss

Table 14.2.24-3: Minimum test times due to HT high fading conditions

Full Rate 100 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

214

122

101

95

48

45

S

0:3:34

0:2:02

0:1:41

0:1:35

0:0:48

0:0:45

hh:mm:ss

Full Rate 120 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

m

min test time

178

102

84

79

S

0:2:58

0:1:42

0:1:24

0:1:19

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 tables 14.2.24-4 through 14.2.24-9.

For STATIC channel conditions the target number of samples indicated in table 14.2.24-4 shall be taken.

Table 14.2.24-4: Statistical test limits for GSM 700, T-GSM 810, GSM 850 and GSM 900 STATIC

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)

WFS 12.65

Frames

12650

50

0.010000

0.012340

27958

560

00:09:20

Class1b

12650

9050

0,005000

0,006170

55916

6

00:00:06

Table 14.2.24-5: Statistical test limits for GSM 700, T-GSM 810, GSM 850 and GSM 900 RA 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)

WFS 12.65

Frames

12650

50

0.010000

0.012340

27958

560

00:09:20

Class1b

12650

9050

0,007200

0,008885

38830

4

00:00:04

Table 14.2.24-6: Statistical test limits for GSM 700, T-GSM 810, GSM 850 and GSM 900 HT 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)

WFS 12.65

Frames

12650

50

0.010000

0.012340

27958

560

00:09:20

Class1b

12650

9050

0,006200

0,007651

45093

5

00:00:05

Table 14.2.24-7: Statistical test limits for GSM 700, T-GSM 810, GSM 850 and GSM 900 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)

WFS 12.65

frames

12650

50

0.010000

0.012340

27958

560

00:09:20

Class1b

12650

9050

0,003500

0,004319

79880

9

00:00:09

WFS 8.85

frames

8850

50

0.010000

0.012340

27958

560

00:09:20

Class1b

8850

5650

0,003800

0,004689

73573

13

00:00:13

WFS 6.60

frames

6600

50

0.010000

0.012340

27958

560

00:09:20

Class1b

6600

3900

0,001500

0,001851

186386

48

00:00:48

Table 14.2.24-8: Statistical test limits for DCS 1 800 and PCS 1 900 HT 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)

WFS 12.65

Frames

12650

50

0.010000

0.012340

27958

560

00:09:20

Class1b

12650

9050

0,006600

0,008144

42360

5

00:00:05

Table 14.2.24-9: Statistical test limits for DCS 1 800 and PCS 1 900 TU high no FH

1.8 and 1.9GHz

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)

WFS 12.65

Frames

12650

50

0.010000

0.012340

27958

560

00:09:20

Class1b

12650

9050

0,006200

0,007651

45093

5

00:00:05

WFS 8.85

Frames

8850

50

0.010000

0.012340

27958

560

00:09:20

Class1b

8850

5650

0,005900

0,007281

47386

8

00:00:08

WFS 6.60

Frames

6600

50

0.010000

0.012340

27958

560

00:09:20

Class1b

6600

3900

0,001700

0,002098

164458

42

00:00:42