14.2.19 Reference sensitivity – TCH/AFS-INB

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

The reference sensitivity is the signal level at the MS receiver input at which a certain FER for in band signalling codewords or frames must be achieved.

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

1. At reference sensitivity level, the TCH/AFS-INB FER shall meet the reference sensitivity performance of table 1 in 3GPP TS 45.005 subclause 6.2.

The delays associated with Loop I remain constant for all of the following circumstances:

– For a given MS implementation.

– For the duration of the MS being powered on.

3GPP TS 44.014 subclause 5.1.7a.1. 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. 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. 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 the following set of codecs modes:

Codec Mode

TCH/AFS in kbit/s









The Initial Codec Mode shall be set to the lowest codec mode (CODEC_MODE_1).

The following decision threshold and hysteresis values in terms of normalized carrier to interference ratio (C/Inorm), shall apply for Codec Mode Command / Request (MC, MR):





18,5 dB

+ 


12,5 dB

20,5 dB


6,5 dB

14,5 dB


 

8,5 dB

The SS transmits Standard Test Signal C1 on the traffic channel using the Initial Codec Mode (ICM).

The SS continuously sends a CMC corresponding to the highest codec mode (CODEC_MODE_4).

The SS commands the MS to loop back in band signalling codewords by closing a Loop I. 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 shall change the Codec Mode Indication and Codec Mode Command to the neighbour mode every 22 speech frames (440 ms) by following a scanning pattern (1->2->3->4->4->3->2->1). CMI should initially be increased. CMC should initially be decreased. The CMI/CMC pattern shall be repeated until the minimum required number of frame samples has been sent to the MS.

d) The SS compares the in band signalling codewords/frames it sends to the MS with the in band signalling codewords/frames which are looped back from the receiver after demodulation and decoding, and checks for in band signalling (CMI/CMC) frame errors.

e) The SS determines the frame error events by examining sequences of at least the minimum number of samples of consecutive frames. All frames should be considered when computing the frame error rate: those corresponding to a downlink CMI/CMC transitions and those without downlink CMI/CMC transitions.

NOTE: The delays associated with Loop I are not specified, and will be MS implementation dependant. Loop I should be considered as having two separate parts (DL CMC -> UL CMI and DL CMI -> UL CMR). The delays associated with the two parts may differ. The SS should ensure that the correctly looped inband bits are compared. The delays associated with Loop I will remain constant for the duration of the test, thus every UL frame received by the SS will have only one possible expected value.

Maximum/Minimum Duration of Test

Maximum/minimum: 50 minutes (GSM850, GSM900, DCS1800, PCS1900). Test requirements

The frame error rates measured for different channels shall not exceed the test limit error rate values given in table 14.2.19-1 or 14.2.19-2.

Table 14.2.19-1: Limits for GSM 400, GSM 700, T-GSM 810, GSM 850 and GSM 900 sensitivity


Propagation conditions Tuhigh

Test limit
error rate %

Minimum No.
of samples




Table 14.2.19-2: Limits for DCS 1 800 and PCS 1 900 sensitivity


Propagation conditions TUhigh

Test limit
error rate %

Minimum No.
of samples