26.20 Enhanced Power Control

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

26.20.1 Enhanced Power Control / MS Supports EPC

26.20.1.1 Conformance requirements

The purpose of the Mobile Station Classmark 3 information element is to provide the network with information concerning aspects of the mobile station. The contents might affect the manner in which the network handles the operation of the mobile station. The Mobile Station Classmark information indicates general mobile station characteristics and it shall therefore, except for fields explicitly indicated, be independent of the frequency band of the channel it is sent on.

<Classmark 3 Value part> ::=

{ 0 | 1 < High Multislot Capability : bit(2) > } —Release 5 starts here.

{ 0 | 1 < GERAN Iu Mode Capabilities > } — ‘1’ also means support of GERAN Iu mode

< GERAN Feature Package 2 : bit >

GERAN Feature Package 2 (1 bit field)

This field indicates the MS support of the GERAN Feature Package 2. The GERAN Feature Package 2 includes Enhanced Power Control (EPC) (see 3GPP TS 45.008).

0 GERAN feature package 2 not supported.
1 GERAN feature package 2 supported.

In A/Gb mode, when assigned a TCH or O-TCH, the MS shall configure the channel in enhanced power control (EPC) mode if so commanded by BSS in the channel assignment (see 3GPP TS 44.018). On such a channel, EPC may be used for uplink power control and/or downlink power control.

When on a channel in EPC mode,

  • the MS shall use the EPCCH in the uplink for EPC measurement reporting (see subclause 8.4.1b).
  • the MS shall, depending on what is signalled in the L1 header of the downlink SACCH (see 3GPP TS 44.004) and during channel assignment (see 3GPP TS 44.018), obey either the EPC Uplink Power Control Command (sent on the EPCCH in the downlink) or the Ordered MS Power Level (sent in the L1 header of the downlink SACCH).

– If the signalling indicates that EPC shall be used in the uplink, the MS shall employ the most recently commanded EPC power control level, as indicated by the EPC Uplink Power Control Command sent on the corresponding EPCCH in the downlink. The EPC Uplink Power Control Command is sent once every EPC reporting period (see subclause 8.4.1b). The MS shall ignore the Ordered MS Power Level sent in the SACCH L1 header in the downlink.

– If the signalling indicates that normal power control shall be used in the uplink, the MS shall ignore the EPC Uplink Power Control Command and use normal power control.

When in enhanced power control (EPC) mode, the MS shall for uplink power control obey either the EPC Uplink Power Control Commands or the Ordered MS Power Level. This is controlled by signalling via the SACCH L1 header in the downlink (see 3GPP TS 44.004) and during channel assignment (see 3GPP TS 44.018 and 3GPP TS 44.118). The type of power control commands to be obeyed by the MS during one SACCH period is determined by what is signalled in the L1 header during the previous SACCH period and, before any SACCH block has been correctly decoded, by what is signalled during channel assignment.

NOTE: This signalling via the SACCH L1 header and during channel assignment only controls the uplink power control mechanism. In A/Gb mode, EPC measurement procedures shall always be followed by the MS when on a TCH or O-TCH in EPC mode. Similarly in Iu mode, EPC measurement procedures shall always be followed by the MS when on a DBPSCH in EPC mode.

When the MS is ordered to obey the Ordered MS Power Level, the timing according to subclause 4.7.1 applies.

When the MS is ordered to obey the EPC Uplink Power Control Command, it shall, upon receipt of an EPC Uplink Power Control Command on an EPCCH in the downlink, change to the new power level on the corresponding uplink channel at the first TDMA frame belonging to the next EPC reporting period (as specified in subclause 8.4.1b).

References

3GPP TS 24.008, subclause 10.5.1.7

3GPP TS 45.008, subclause 4.2, subclause 4.7.3

26.20.1.2 Test purpose

To verify that a MS that supports EPC indicates to the network that it supports GERAN feature package 2.

To verify that when commanded to do so the MS shall configure the assigned TCH or O-TCH channel in EPC mode.

To verify that when on a channel in EPC mode the MS ignores the EPC Uplink Power Control command if the signalling indicates that normal power control shall be used in the uplink.

To verify that when in EPC mode, the MS shall for uplink power control obey either the EPC Uplink Power Control Commands or the Ordered MS Power Level.

26.20.1.3 Method of test

Initial Conditions

System Simulator:

1 cell, default parameters except IMSI Attach-detach shall be applied.

Mobile Station:

MS is switched off.

Specific PICS Statements:

PIXIT Statements:

Test Procedure

The MS is switched on (or its power is re-applied). After the start of the LOCATION UPDATING procedure the SS initiates a CLASSMARK ENQUIRY procedure. The MS shall report in the CLASSMARK CHANGE that it supports “GERAN FEATURES PACKAGE 2”. The SS then completes the LOCATION UPDATING procedure assignment a mobile identity.

The MS is paged and a MT speech call (TCH) is established with an early assignment (before CONNECT). The MS is assigned a channel that supports “Enhanced Power Control” with the power level set to the maximum allowed. The MS shall send EPCCH Message block on the EPCCH channel. The reported power level is the one set in the ASSIGNMENT COMMAND.

The SS checks that the MS is using the enhanced power control mechanism by commanding it to lower its power level. This is checked on the subsequent EPCCH Message blocks sent by the MS on the EPCCH.

“Enhanced Power Control” is disabled and the SS checks that the MS goes back to using the normal power control mechanism in MEASUREMENT REPORT messages on SACCH.

Maximum Duration of Test

Expected Sequence

Step

Direction

Message

Comments

1

MS

The MS is switched on (or its power is re-applied).

2

MS -> SS

CHANNEL REQUEST

3

SS -> MS

IMMEDIATE ASSIGNMENT

4

MS -> SS

LOCATION UPDATING REQUEST

5

SS -> MS

CLASSMARK ENQUIRY

6

MS -> SS

CLASSMARK CHANGE

Classmark 3 should be present indicating that the MS supports GERAN Feature Package 2.

7

SS -> MS

LOCATION UPDATING ACCEPT

Assign a TMSI

8

MS -> SS

LOCATION UPDATE COMPLETE

9

SS -> MS

CHANNEL RELEASE

10

SS -> MS

PAGING REQUEST TYPE 1

Sent on the correct paging subchannel. "Mobile Identity" IE contains the TMSI allocated to the MS

11

MS -> SS

CHANNEL REQUEST

12

SS -> MS

IMMEDIATE ASSIGNMENT

13

MS -> SS

PAGING RESPONSE

14

SS -> MS

SETUP

Message does not contain the signal IE.

15

MS -> SS

CALL CONFIRMED

16

SS -> MS

ASSIGNMENT COMMAND

Set the power level to the maximum allowed for the class of MS being tested and enable EPC.

17

MS -> SS

ASSIGNMENT COMPLETE

Sent on the new channel.

18

SS

Change the SACCH L1 header to indicate “EPC in use for MS power control”.

19

SS -> MS

ALERTING

20

MS

An alert indication is given by the MS.

21

MS

The MS is made to accept the call.

22

MS -> SS

CONNECT

23

MS

The TCH shall be through connected by both directions in the dedicated mode.

24

SS -> MS

CONNECT ACKNOWLEDGE

25

MS -> SS

EPCCH MESSAGE BLOCK

Message is sent on EPCCH. Determine the RF power control level being used from the SACCH L1 header.

26

SS

Command the MS to lower its power level by 2 dB (setting Ordered MS power level in the SACCH header) using the EPC UPLINK POWER CONTROL COMMAND. Sent on the EPCCH.

27

MS -> SS

EPCCH MESSAGE BLOCK

Message is sent on EPCCH. Confirm that the reported power level used by the MS is 2dB lower.

28

SS -> MS

ASSIGNMENT COMMAND

Disable EPC, using normal power control. Set power level to value seen in step 27.

29

MS -> SS

ASSIGNMENT COMPLETE

30

SS

Change the SACCH L1 header to indicate “EPC not in use for MS power control”.

31

SS

Command the MS to lower its power level by 2 dB using the EPC UPLINK POWER CONTROL COMMAND. Sent on the EPCCH.

32

MS -> SS

MEASUREMENT REPORT

Message is sent on SACCH. Report power level used by MS should not have changed from that used in step 27.

33

SS

Change the SACCH L1 header to indicate the MS to lower its power by 4 dB.

34

MS -> SS

MEASUREMENT REPORT

Message is sent on SACCH. Confirm that the reported power level used by the MS is 4 dB lower than that reported at step 27.