bts loop testing suja june 2004

© NOKIA – NET/BTS Test loops/SDSh/29.05.2004 PAGE 1 CONFIDENTIAL

BTS TEST LOOPS

The MetroSite and UltraSite BTS provides functionality that allows data to be looped to facilitate verification – validation - maintenance testing.


Test loop introduction

(E)RECVA

EQDSP

(E)FBIA

CHDSP

(E)TXA (E)RXA

DAC ADC

TX RF RX RFLOOP MODULE

(E)DIBA

DTRU

TC or test equipment

MS or test equipment

AIR1

AIR4

AIR3

AIR2

ABIS4

ABIS1

ABIS0

ABIS2

ABIS3CHDSP configures the loop as commanded by the O&M software. The actual command may come from BSC or BTS Manager.

The CHDSP generates the test data which is looped around. The CHDSP is commanded by the O&M to use a particular encoding/ decoding scheme. The test data is processed accordingly and gets finally looped back.

The CHDSP compares the Tx and Rx data over time and reports the error to the O&M SW.


Test loop back points


AIR side loop back points

• AIR1 EQDSP SW reads the TX burst, which was sent by CHDSP. EQDSP makes simplified GMSK modulation and bit normal detection and loops the bit detected TX burst back 3 timeslots delayed. This means that the loop does not interfere with other timeslots.

• AIR2 The TX burst is looped back from D/A to A/D at RF board. EQDSP sees this loop as a normal bit detection. UC must activate timeslot 3 slots earlier to give correct diversity info for the loop. CHDSP must tell the right frequency control bytes to RF three timeslots earlier to RF parts because the TX burst is looped back right away. From CHDSP point of view this is loop is the same as Air3 except that TRX loop bit is not set in the TX burst. This loop point can be used only at production testing where connection from D/A to A/D is made in the production tester. I.e. this looping point is not available in the final product. This loop "steals" one timeslot.

• AIR3 The TX burst is looped back from TRX loop block in the RF parts. EQDSP makes normal bit detection. UC must activate timeslot 3 slots earlier to give correct diversity info for the loop. CHDSP must tell the right frequency control bytes to RF three timeslots earlier to RF parts because the TX burst is looped back right away. CHDSP must also set TRX-loop bit in the TX burst so that the TRX-loop block knows which timeslot to loop back. This loop "steals" one timeslot.

• AIR4When this loop point is chosen the both EQDSP and CHDSP operate normally. There must be an external device that can receive the TX burst and loop them back 3 timeslots later on RX frequency. E.g. either CMD tester or MS.


ABIS loop back points

•ABIS0The loop mechanism makes hard decisions of the soft bits in a received bursts and sends them back as downlink bursts (on the physical channel where ABIS0 is activated). Deinterleaving and decoding are not used for this loop test. ABIS0 is implemented in EDGE BTSs only. ( Suja: Not implemented)ABIS1CHDSP loops back the uplink TRAU frame to downlink TRAU frame inside the CHDSP processor.I.e. the channel decoded block is given to channel encoder. EDGE BTSs can also loop back the signaling channels with Abis1. This is defined as ABIS1S.ABIS2UC configures the (E)DIBA into loop mode on the looped Abis channel. This loop requires that CHDSP makes uplink TRAU frames but changes the frame type as a downlink TRAU frame. So far ABIS2 does not work in EDGE and use instead ABIS1.ABIS3 This loop is the same as Abis2 but now UC does not configure (E)DIBA to loop mode. I.e. loop can be done from TRUA (with UC control) or as a wire loop from Abis connection.ABIS4 When this loop point is chosen the CHDSP must operate normally. There must be an external device that can receive the uplink TRAU frames and loop them asdownlink TRAU frames.


Test loop features• A TS must be inactive when a test loop is run on that TS.

Loop tests can be run for only 1TS at a time.• When a loop test is requested on a particular timeslot all

other timeslots should operate normally.• Loop tests cannot be performed on BCCH (TS0) and on TS

configured as Control channels (SDCCH, PBCCH etc).• AIR2 is not supported in UltraSite.• The TRX loop test reserves two radio time slots, one for the

Downlink and one for the Uplink directions, 3 timeslots apart.• Both fixed data and PRBS data can be selected for looping

around. • In case of PRBS data failure to synchronize shall be reported

of synchronizations is not achieved after 60 frames.• On removal or end of loop test, the TRX shall operate

normally.• The Channel mode, TS, Number of blocks, Tx Power and

ABISn-AIRn must be selected for a loop test.


Test loop- Interaction with other features• Loop tests cannot be performed on a TRX that

is defined in BB hopping or Antenna Hopping sector

• With Intelligent Downlink diversity feature, one can select Main/Aux TRX from BTS Manager.

• With ECELL feature loop tests may not be possible on Extended TRXs.

• Uplink Incremental Redundancy and Downlink Pointer retransmission features can be tested use ULIR and DLPR loop tests.These tests are run by as part of DSP Regression testing.


CHDSP <-> UC interface for TL

The UC-CHDSP interface messages that are exchanged for a basic test loop operation are listed below

UC -> CHDSP > INI ( INItialization message)UC -> CHDSP > TSC ( Times Slot Configuration)UC -> CHDSP > CHC ( CHannel Configuration)*UC -> CHDSP > BAT ( Bit Allocation Table)UC -> CHDSP > TEC (TEst Command)CHDSP -> UC > TLR ( Test Loop Response)

* BAT is required for ABIS3 loops only


How to run loop tests

• By DSP Testers

• By BTS Manager• TRX test• TRX loop test

• By BSC MML command• TRX test• ABIS loop test ( fixed, Dynamic)


DSP Tester Loop tests


DSPT - Initialization Message


DSPT- TSC message


DSPT- CHC Message


DSPT- TEC


TLRword bits Purpose

0 (u16) b15-b10 DSP_TLR_MSG_TYPE

b9-b0 DSP_TLR_MSG_LENGTH

1 (u16) b15-b8 Amount of 1b bits in one block

b7-b0 Timeslot number 0-7

2 (u16) b15-b8 Amount of 2cl bits in one block

b7-b0 Subchannel number 0-7

3 (u16) b15-b0 Test response

4-5 (u32) LSW first Bit error number of loop test

6 (u16) b15-b0 Bits in block

7-8 (u32) LSW first Sum of SNR values

9-10 (i32) LSW first Main_branch_RXLEV_sum (each summed value is on the scale = -20 - (+90), 0 corresponds to -110 dBm and step size is 1 dBm)

11-12 (i32) LSW first Div_branch_RXLEV_sum (each summed value is on the scale = -20 - (+90), 0 corresponds to -110 dBm and step size is 1 dBm)

13-14 (u32)

LSW first Number or bad_frames

15-16 (u32)

LSW first RBER1b

17-18 (u32)

LSW first RBER2

19-20 (u32)

LSW first BFI_OR_UFI_0 (DSP tester only)Also IR_BLER_PS1

21-22 (u32)

LSW first RBER1B_BFI_UFI (DSP tester only)Also IR_BLER_PS2

23-24 (u32)

LSW first UFR (DSP tester only)Also IR_BLER_PS3

25-26 (u32)

LSW first EVSIDR (DSP tester only)

27-28 (u32)

LSW first RBER_SID2 (DSP tester only)

29-30 (u32)

LSW first ESIDR (DSP tester only)

31-32 (u32)

LSW first RBER_SID_1OR2 (DSP tester only)


Loop Tests initiated by MMI:

TRX testsTRX Loop tests


BTS Manager : TRX test


BTS Manager : TRX test[1]The following set of loop tests are commanded sequentially by them O&M SW:RF_DIBA_LOOP_MAIN Main rx Lev & BER1. ABIS1 - AIR3 SLAVE_TRC_CHDSP_FILTER_LOOP

RF_DIBA_LOOP_DIV Div rx Lev & BER2. ABIS1 - AIR3 SLAVE_TRC_CHDSP_FILTER_LOOP

RFMIF_LOOP Floor noise3. ABIS1 - AIR4SLAVE_TRA_CHDSP_AIR_LOOP

ABIS_EQ_LOOP BBB BER 4. ABIS2 - AIR1

SLAVE_TRC_DIBA_EQDSP_LOOP


BTS Manager : TRX test[1]

START/STOP_PHASE_ERROR_TRACE Start/stop loop5/6. ABIS1 - AIR3SLAVE_TRC_CHDSP_FILTER_LOOP

VSWR_LOOP VSWR & antenna detection7. ABIS1 - AIR3SLAVE_TRC_CHDSP_FILTER_LOOP

The channel coding scheme commanded in the CHC is TCH-FS, MCS-5 or MCS-9 depending on that selected by the BTS Manager.


BTS Manager : TRX Loop test

Just a single loop test is run. ABISx-AIRx and the channel coding scheme is that selected


BTS Manager : TRX Loop test result


BSC initiated Loop tests

-TRX test-ABIS loop test


BSC test -TRX test• To initiate test

ZUBS:BTS=53,TRX=1:MODE=[x]: [RTSL];where MODE(x) = 0 for 8PSK (EDGE) and 1 for

GMSK The loops run are exactly same like TRX tests run by

BTS Manager for GMSK(mode=0) and MCS-9.(mode=1)

• To check test reportZUBP:TR: BTS=53,TRX=1:;

• To delete test reportZUBD:TR: BTS=53,TRX=1:;


BSC test - TRX test report

The format of the test report generated by the BSC for a TRX test is as follows:

RADIO NETWORK TEST REPORT TRX TEST BCF-050 BTS-053 TRX-001TX_RTSL-001 RX_RTSL-006 TEST RESULT: FAILEDREASON: RESULT IS NOT WITHIN THRESHOLD VALUE RANGE TEST EXECUTED: 2004-05-29 15:47:06 TRANSMITTED POWER......................... 15 DBM MAIN RX:BIT ERROR RATIO ...................(BER).. 0.0000 %RX SENSITIVITY............................ -114 DBM DIVERSITY RX:BIT ERROR RATIO ...................(BER).. 0.0000 %RX SENSITIVITY............................ - END OF REPORT


BSC - ABIS Loop test

• To initiate testZUBK:TEST:BTS=53,TRX=1:<RTSL>:SEL=<Y>where ABIS CONNECETION(Y)= FIXED(0) or DYNAMIC(1)

ABIS3-AIR1 loop is run for TCH-FS in case Fixed(0) is selected andABIS3-AIR1 loop is run for MCS-1 in case Dynamic(1) is selected.

• To check test reportZUBP:AL: BTS=53,TRX=1:;


BSC test – ABIS Loop test reportThe format of the test report generated by the BSC for a

ABIS Loop test run on TS-0 is as follows:RADIO NETWORK TEST REPORT ABIS LOOP TESTBCF-050 BTS-053 TRX-001TEST RESULT: INCONCLUSIVEREASON: SOME OF THE RADIO TIME SLOTS ARE NOT TESTED SUCCESSFULLY START DATE.............. 2004-05-29START TIME.............. 15:54:10LOOP DURATION........... 00:00:05:000THRESHOLD OF FER........ 0.1000 %THRESHOLD OF BER........ 0.1000 %RTSL RESULT ACTION FER(%) BER(%) ET_PCM TSL SUB_TSL--------------------------------------------------------------------- 0 PASSED TESTED 0.0000 0.0000 50 1 0 1 INCONCLUSIVE NOT TESTED - - 50 1 1 REASON: TESTING IS NOT REQUESTED TO THIS TEST OBJECT 2 INCONCLUSIVE NOT TESTED - - 50 1 2 REASON: TESTING IS NOT REQUESTED TO THIS TEST OBJECT 3 INCONCLUSIVE NOT TESTED - - 50 1 3 REASON: TESTING IS NOT REQUESTED TO THIS TEST OBJECT 4 INCONCLUSIVE NOT TESTED - - 50 2 0 REASON: TESTING IS NOT REQUESTED TO THIS TEST OBJECT 5 INCONCLUSIVE NOT TESTED - - 50 2 1 REASON: TESTING IS NOT REQUESTED TO THIS TEST OBJECT 6 INCONCLUSIVE NOT TESTED - - 50 2 2 REASON: TESTING IS NOT REQUESTED TO THIS TEST OBJECT 7 INCONCLUSIVE NOT TESTED - - 50 2 3 REASON: TESTING IS NOT REQUESTED TO THIS TEST OBJECT END OF REPORT


Test loop users• DSP Tester (Any ABISx-AIRx tests)

BTS SW Development (DSP)

RF Development

Layer 1 Regression testing

RF performance testing

• BTS Manager/MMI ( TRX tests and TRX loop tests)

BTS SW Release testing

Metrosite/Ultrasite TRX Production testing

Installation/Maintenance activities in field

• BSC by MML commands (TRX tests and ABIS Loop tests)

BTS SW Release testing

Installation/Maintenance activities in field


Testing TLs in DSPSW

• In DSP SW supports all AbisN, AirN loops except any combination involving Abis0,Abis 2 loops and Air 2 loops. Loops apart from these, should function for full rate, half rate, and AMR speech, CD, GPRS and EGPRS. Constant and random data generation are to be supported.

• Layer 1 regression is a automated test suite used by SW developers to verify channel coding in Layer 1. These test are performed as part of the regression test prior to official test packets or pre releases. DSP tester is used.


Layer 1 Regression Testing

The Layer 1 Regression testing tests the following loops before every minor release using DSP TesterABIS1-AIR1, ABIS1-AIR3 and ABIS3-AIR1 for all of following channels:TCH, Speech TCH/HS, TCH/FS, TCH/EFS [GMSK]

TCH/AHS, TCH/AFS [GMSK]

TCH Transparent CSD TCH/F2.4, TCH/F4.8, TCH/F9.6 and TCH/F14.4. [GMSK]

TCH CSD Non-Transparent TCH/F2.4, TCH/F4.8, TCH/F9.6 and TCH/F14.4.[GMSK]

GPRS CS1 and CS2. [GMSK]

EGPRS MCS-1 to MCS-9.[GMSK\8PSK]


RF Performance testingLoop Channel Supported

Air 4, Abis 1 FACCH/FFACCH/HSDCCHRACHPRACH 8 bitPRACH 11 bitTCH/FSTCH/F14.4TCH/F9.6TCH/H4.8TCH/EFSTCH/HSPDTCH/CS-1PDTCH/CS-2PDTCH/MCS-1PDTCH/MCS-2PDTCH/MCS-3PDTCH/MCS-4PDTCH/MCS-5PDTCH/MCS-6PDTCH/MCS-7PDTCH/MCS-8PDTCH/MCS-9TCH/AFS12.2TCH/AFS7.4TCH/AFS5.9TCH/AFS4.75TCH/AHS7.4TCH/AHS5.9TCH/AHS4.75PACCH

Air 4, Abis 0 TCH/FS, PDTCH/MCS5

For AIR4 loop a external RF equipment like CMD,CMU300 or RACAL is necessary.

CMD supports only TCHFS.RACAL supports only PDTCH GPRS/EGPRS channels.CMU300 tests all channels except AMR.

DSP Tester is used.


RF Development Testing

RF Developers generally use the following loop commanded by DSP tester or BTS Manager

Loop Channel Supported

Air 1, Abis 1 TCH/FS

Air 1, Abis 3 TCH/FS. MCS5

Air 3, Abis 1 TCH/FS, MCS5

Air 4, Abis 1 GMSK/8PSK, MCS5

Air 4, Abis 0 MCS5


MetroSite and UltraSite Production Tests

Loop Channel Supported Comments

Air 3, Abis 1 TCH/FS, GMSK

Air 4, Abis 1 GMSK/8PSK, MCS5 Absolute Sensitivity

Air 4, Abis 0 GMSK/8PSK,UNCODED NER

Air 4, Abis 3 GMSK,TCH/FS BTS DTRU Loop Test

For Connectsite 10 and EDGE Metrosite products production these these selected tests are run.

The tests are activated using the MMI interface.

Loop Channel Supported Comments

Air 3, Abis 1 8PSK\MCS9, GMSK\TCHFS TRX loop Cal + TRX loop Test (cal GMSK, Test 8PSK)

Air 3 Abis 3 TCH/FS BB2/BOI Unit tester (GMSK)

Air 4, Abis 0 GMSK/8PSK,UNCODED NER

Air 4, Abis 1 8PSK\MCS9, GMSK\TCHFS Sensitivity (GMSK, 8PSK)

Air 4, Abis 3 TCH/FS DTRU loop final tester DTRU loop (at the moment GMSK)

For Ultrasite production these these selected tests are run.

The tests are also activated using the MMI interface.


SW Release Testing/ Field Tests

• The TRX tests and ABIS Loop tests run from BSC.• The TRX tests run from the MMI• AIR4/ABIS1 and AIR4/ABIS4 loop tests are run

from MMI (This is specific to customer requirement where these two loop tests are supported).

• Open Issue: The present requirement for Loop Test that is developed for CS3 and CS4 coding scheme implementation is yet to be clarified.


Some contact points

• TRX Loop test requirements: Eric Jones

• RF Development testing: John LoPresti, Andy Inman

• MetroSite Production tests : Tom Tinsley

• UltraSite Production tests: Bob Wilson & Janne Moilanen

• Software release testing: Jim Kennard.

• RF Performance tests: Santosh Nath


References

1 NOLS

2 Loop Test Requirements:Nokia_BTS\CM_Ctrl\CX4.1\System\BTS Requirements\Loop Test\Version 0.0.2


THANK YOU

ANY QUESTIONS?

bts loop testing suja june 2004

Documents

loop point

abis loop

loop mode

loop steals

loop mechanism

wire loop

end of loop test

trx loop test reserves