20.2 Cell selection with varying signal strength values

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

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

20.2.1 Definition

For definition see conformance requirement.

20.2.2 Conformance requirement

1. The MS shall:

The MS shall search all RF channels within its bands of operation, take readings of received RF signal level on each RF channel, and calculate the RLA_C for each. The averaging is based on at least five measurement samples per RF carrier spread over 3 to 5 s, the measurement samples from the different RF carriers being spread evenly during this period.

3GPP TS 05.08 / 3GPP TS 45.008, subclause 6.2.

1.1 The MS shall search all RF channels within its bands of operation, take readings of received RF signal level on each RF channel, and calculate the RLA_C for each.

1.2 The averaging is based on at least five measurement samples per RF carrier spread over 3 to 5 s, …

1.3 …. the measurement samples from the different RF carriers being spread evenly during this period.

2. These quantities termed the "received level averages" (RLA_C), shall be unweighted averages of the received signal levels measured in dBm..

GSM 05.08 / 3GPP TS 45.008, subclause 6.1.

20.2.3 Test purpose

1. To verify that:

1.1 The MS meets conformance requirement 1.1.

1.2 The MS meets conformance requirement 1.2.

1.3 The MS meets conformance requirement 1.3.

2. To verify that the MS meets conformance requirement 2.

20.2.4 Method of test

20.2.4.1 Initial conditions

Parameters changed from the default values in table 20.1.

Parameter	Carrier 1	Carrier 2	Carrier 3	Carrier 4	Carrier 5	Carrier 6
RF Signal Level (dBV emf() / dBm)	23 / -90	58 / -55	OFF	OFF	OFF	OFF
RXLEV_ACCESS_MIN (dBV emf() / dBm)	13 / -100	13 / -100

C1	10	53

For an E-GSM MS carrier 1 ARFCN is chosen in the E-GSM band.

Specific PICS Statements:

–

PIXIT statements:

– averaging time Tav

20.2.4.2 Procedure

a) The SS transmits on carriers 1 and 2. After a period of b  Tav carrier 2 reduces its transmit level to ‑85 dBm (28 dBV emf( )). After a further period of a  Tav, carrier 2 increases its transmit level again to ‑55 dBm (58 dBV emf( )). Switching of carrier 2 continues with these levels and duty cycle until the end of the test.

Tav is the averaging time declared by the manufacturer.

The parameters a and b are chosen according to the following rules:

(a + b)  Tav > Tav

0 < a  Tav < 2/3  Tav

0,5  Tav < b  Tav < Tav

In the equations < and > means at least one TDMA frame less or greater than the given value.

While satisfying the conditions given above:

a is chosen to be as close as possible to 2/3.

b is chosen to be as close as possible to 0,5.

b) The MS is switched on.

c) The SS monitors all RA requests from MS on carriers 1 and 2.

20.2.5 Test requirements

In step c), the first response from the MS shall be on carrier 2 within 33 s.

NOTE 1: With the selected duty cycle it can be guaranteed that a "good" MS passes the test even at the worst case situations. The minimum averaged value of carrier 2 is in any case higher or equal to -75 dBm which is still 6 dB above carrier 1’s level (for a "good" MS).

NOTE 2: With the selected levels and duty cycle the probability that a "bad" MS (i.e. MS that averages over shorter period than 3 s) fails the test is maximized. However, it can not be guaranteed that all the MSs not fulfilling the conformance requirement of averaging or uniform sampling will fail this test.