03a_tcsm2 Basic Operation

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TCSM2TCSM2basic operationbasic operation

BSS S11.5

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TCSM2 basic operationTCSM2 basic operation

After studying this module you will:

• be able to explain the use of the TCSM2 in the BSS• know about different TC configurations and their Ater interfaces• know the TCSM2 architecture• know about TCSM2 rack, cartridges and plug-in units• understand configuration of TCSM2

Refer to S11.5 Documentation:• Descriptions\ Product descriptions\ Product description for TCSM2E

Refer to S11.5 Documentation:• Descriptions\ Product descriptions\ Product description of TCSM2E

See additional information in S11.5 Documentation:• Integrate\ Q1 Interface\ BSS transmission management\ Configuring a new

transcoder\ Configuring a TCSM unit (TCSM2)• Optimise and Expand\ Transmission\ Modifying an existing transcoder configuration• Monitor\ Routine testing of TCSM2\ Interrogating routine test information• Descriptions\ Hardware descriptions\ Functional unit descriptions\ TCSM2\ TCSM2

overview• Commission\ Commissioning TCSM2\ Commissioning TCSM2• Descriptions\ Functional area descriptions\Transmission\TCSM2 Functionalities\

Overview of TCSM2 Functionalities• Descriptions\ Hardware descriptions\ Plug-in unit descriptions\ TRCO\ TRCO

Overview• Descriptions\ Hardware descriptions\ Plug-in unit descriptions\ ET2E, ET2E-C, ET2E-

S, ET2E-SC\ ET2E, ET2E-C, ET2E-S, ET2E-SC overview

HW requirements: one TCSM and a terminal for each group

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Operating environment of the TCSM2EOperating environment of the TCSM2E

BSC MSC

AterInterface

AInterface

E1

E1

E1

E1

TCSM2EUnit

TCSM2EUnit

TCSM2EEQUIPMENT

1

3

6

2

45

7

0

0

. . .

. . .

1

3

6

2

45

7

Refer to S11.5 Documentation:

• Descriptions\ Product descriptions\ Product description of TCSM2A and TCSM2E\Overview of product description of TCSM2A and TCSM2E

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Channel allocation for Channel allocation for A A andand AterAter ififA interface

2nd A-IF trunk

3rd A-IF trunk

4th A-IF trunk

1 2 3 4 5 6 7 80001 01 02 0302 04 05 06 0703 08 09 10 1104 12 13 14 1505 16 17 18 1906 20 21 22 2307 24 25 26 2708 28 29 30 3109 01 02 0310 04 05 06 0711 08 09 10 1112 12 13 14 1513 16 17 18 1914 20 21 22 2315 24 25 26 2716 28 29 30 3117 01 02 0318 04 05 06 0719 08 09 10 1120 12 13 14 1521 16 17 18 1922 20 21 22 2323 24 25 26 2724 28 29 30 3125 01 02 0326 04 05 06 0727 08 09 10 1128 12 13 14 1529 16 17 18 1930 20 21 22 2331 24 25 26 27

LAPD

1 2 3 4 5 6 7 8000102 0203 0304 0405 0506 0607 0708 0809 0910 1011 1112 1213 1314 1415 1516 1617 1718 1819 1920 2021 2122 2223 2324 2425 2526 2627 2728 2829 2930 3031 31

01

1st A-IF trunk

Ater interface

64 kb/s Traffic Channels


• Descriptions\ Product descriptions\ Product description of TCSM2A and TCSM2E\Architecture of TCSM2A and TCSM2E\ Time slot allocation for TCSM2E

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TranscodingTranscoding and and submultiplexingsubmultiplexing

7 6 5 4 3 2 1 160 159 158 157 156 157 154

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

x x b1 b2 x x x x

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

2 Mbit/s frames from the MSC to the transcoder

2 Mbit/s frames, 125 us

7 6 5 4 3 2 1 160 159 158 157 156 157 154

B1 B2 B3 B4 B5 B6 B7 B8

7 6 5 4 3 2 1 160 159 158 157 156 157 154 7 6 5 4 3 2 1 160 159 158 157 156 157 154

20ms sample, 160 x 2 Mbit/s frames

64 kbit/s timeslot, 8 bits

160 x timeslot from the 160 x 2 Mbit/s frames

DSP for TS 1

DSP for TS 31

160 x 2 bits from timeslot

2 Mbit/s frames, 125 us

20 ms sample, 160 2 Mbit/s frames Mbit/s frames from the transcoder to the BSC (SM2M)

Transcoder TCSM2

The speech signal is divided into 20 ms samples (160 2Mbit/s frames). Each sample is taken from the MSC and passed into the transcoder where the Digital Signal Processor (DSP) performs the RPE-LTP coding of the sample (Regular Pulse Excitation - Long Term Prediction). The resulting coded sample is known as the vocoded block, which contains 260 bits for full rate traffic channels or 112 bits for half rate. Each vocoded block is inserted into a TRAU frame, which contains a vocoded block plus synchronisation bits and control bits giving a total of 320 bits (16 kbit/s) for full rate or 160 bits (8 kbit/s) for half rate. The frame is reassembled in the DSP in the transceiver unit of the BTS. Each traffic timeslot has its own DSP for transcoding.

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InbandInband Signalling between TCSM2 and BTSSignalling between TCSM2 and BTS

TCSM2E BSC BTS64 kb 16 kb 16 kb

33,8 kb

Inband Signalling within the TRAU Frame

16 kb

DSP1

DSP90

2 Mbit/s TRU DSPET

GSW MS

TRX

13 kb

ET2

Mbit/s2

Mbit/s

Inband signalling between TCSM2E and TRX in the BTS

The bit rate after transcoding is 16 kbit/s for full rate traffic channels, which includes 13 kbit/sof transcoded speech/data and 3 kbit/s of control data. For half rate the bit rate is 8 kbit/s, which includes 5.6 kbit/s of speech/data and 2.4 kbit/s of control data. This control data is used for inband signalling between the DSP in the Transcoder and the DSP in the Transceiver Unit of the BTS.

The BTS controls the transcoder with this signalling information for the following purposes:

- shifting between speech and data,- shifting between half and full rate radio channels,- controlling rate adaptation functions for data calls,- timing down link frames for speech frames, and- transferring DTX (discontinuous transmission) information.

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Example: Example: FR TRAU frameFR TRAU frame

12345678910111213141516171819202122232425262728293031323334353637383940

001

C81

D81

D231

D381

D531

D681

D831

D981

D1131

D1281

D1431

D1581

D1731

D1881

D2031

D2181

D2331

D2481

C18

00

C1C9D1D9D16D24D31D39D46D54D61D69D76D84D91D99D106D114D121D129D136D144D151D159D166D174D181D189D195D204D211D219D226D234D241D249D256C19

00


00


00

C4C12D4D12D19D27D34D42D49D57D64D72D79D87D94D102D109D117D124D132D139D147D154D162D169D177D184D191D198D207D214D222D229D237D244D252D259

T1

00

C5C13D5D13D20D28D35D43D50D58D65D73D80D88D95D103D110D118D125D133D140D148D155D163D170D178D185D192D199D208D2151D223D230D238D245D253D260

T2

00

C6C14D6D14D21D29D36D44D51D59D66D74D81D89D96D104D111D119D126D134D141D149D156D164D171D179D186D193D200D209D216D224D231D239D246D254C16T3

00

C7C15D7D15D22D30D37D45D52D60D67D75D82D90D97D105D112D120D127D135D142D150D157D165D172D180D187D194D201D210D217D225D232D240D247D255C17T4

1 2 3 4 5 6 7 8Octet no.

Bit number

One full rate TRAU frame consists of 260 bits speech/data information together with 60 bits that are used for creating the TRAU frame structure (in-band signalling between the two DSPsin the BTS and in the TCSM2).

Those 60 control bits contain information like frame alignment word, frame type, channel type, time alignment information, DTX on/off etc.

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Time slot allocationTime slot allocation

Circuittype

Capacity unit onAter interface

FR speech, EFR speechFR data (14.5, 12, 6 or 3.6 kbit/s)

A

B

C

Supported channels and speech codingalgorithms

D

E

16 kbit/s

8 kbit/s

2 x 16 kbit/s

4 x 16 kbit/s

HR speechHR data (6 or 3.6 kbit/s)

16 kbit/sFR speech, EFR speech, HR speechFR data (14.5, 12, 6 or 3.6 kbit/s)HR data (6 or 3.6 kbit/s)FR speech, EFR speech, HR speechFR data (14.5, 12, 6 or 3.6 kbit/s)HR data (6 or 3.6 kbit/s)HSCSD max 2 x FR data (14.5, 12 or 6 kbit/s)FR speech, EFR speech, HR speechFR data (14.5, 12, 6 or 3.6 kbit/s)HR data (6 or 3.6 kbit/s)HSCSD max 4 x FR data (14.5, 12 or 6 kbit/s)

F AMR speech 16 kbit/s



AMR (Adaptive Multi-Rate) is the newest available speech codec using 16kbit/s on the AterInterface.

In AMR Mode the transcoder rate together with the coding scheme in the BTS will be dynamically adjusted to reach always the best Mean Opinion Score. That means change conditions in the Air Interface will be balanced between voice quality and robustness.

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AMR speech codecAMR speech codec

Full Rate Half rate

12.2

10.2

7.95 7.95 (*)

7.4 7.4

6.7 6.7

5.9 5.9

5.15 5.15

4.75 4.75

Speech bit rate

Voice quality

Robustness

8 AMR codecs for FR and 6 for HR:

1.0

2.0

3.0

4.0

5.0

No Errors 16 dB C/I 13 dB C/I 10 dB C/I 7 dB C/I 4 dB C/I

MOS (Mean Opinion Score)

EFRAMR FR

AMR Full Rate performance compared to Full Rate EFR in Clean Speech

1.0

2.0

3.0

4.0

5.0

No Errors 19 dB C/I 16 dB C/I 13 dB C/I 10 dB C/I 7 dB C/I 4 dB C/I

FRAMR HR

MOS (Mean Opinion Score)

AMR Half Rate performance compared to Full Rate in Clean Speech

Optional extra slideOptional extra slide

(*) Requires 16 kbit/s TRAU, not supported



Codec mode adaptation for AMR is based on received channel quality estimation in both MS and BTS, followed by a decision on the most appropriate speech and channel codec mode to apply at a given time. In high-error conditions more bits are used for error correction to obtain error robust coding, while in good transmission conditions only low amount of bits is needed for sufficient error protection and more bits can therefore be allocated for source coding.

An inband-signalling channel is defined for AMR that enables the MS and the BTS to exchange messages on applied or requested speech and channel codec modes. The above mentioned selected speech codec mode is then sent, by using the inband signalling channel, to the transmitting side, where it is applied for the other link.

BTS commands the MS to apply a particular speech codec mode in the uplink, but MS can only request BTS to apply a particular speech codec mode in the downlink because BTS has an option to override the MS's request.

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Channel allocation for circuit types A, C and FChannel allocation for circuit types A, C and F

1st A-IF trunk

2nd A-IF trunk

3rd A-IF trunk

1 2 3 4 5 6 7 80001 01 02 0302 04 05 06 0703 08 09 10 1104 12 13 14 1505 - 17 18 1906 20 21 22 2307 24 25 26 2708 28 29 30 3109 01 02 0310 04 05 06 0711 08 09 10 1112 12 13 14 1513 - 17 18 1914 20 21 22 2315 24 25 26 2716 28 29 30 3117 01 02 0318 04 05 06 0719 05 09 10 1120 12 13 14 1521 - 17 18 1922 20 21 22 2323 24 25 26 2724 28 29 30 312526272829 --- --- --- --- --- --- --- ---30 --- --- --- --- --- --- --- ---31 --- --- --- --- --- --- --- ---

LAPD

Reserved for CCS7

1st A-IF trunk

2nd A-IF trunk

3rd A-IF trunk

4th A-IF trunk

1 2 3 4 5 6 7 80001 01 02 0302 04 05 06 0703 08 09 10 1104 12 13 14 1505 16 17 18 1906 20 21 22 2307 24 25 26 2708 28 29 30 3109 01 02 0310 04 05 06 0711 08 09 10 1112 12 13 14 1513 16 17 18 1914 20 21 22 2315 24 25 26 2716 28 29 30 3117 01 02 0318 04 05 06 0719 08 09 10 1120 12 13 14 1521 16 17 18 1922 20 21 22 2323 24 25 26 2724 28 29 30 3125 01 02 0326 04 05 06 0727 08 09 10 1128 12 13 14 1529 16 17 18 1930 20 21 22 2331 24 25 26 27

LAPD



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Channel allocation for circuit type BChannel allocation for circuit type B

1st A-IF trunk (HR)

2nd A-IF trunk (HR)

3rd A-IF trunk (HR)

4th A-IF trunk (HR)

5th A-IF trunk (HR)

6th A-IF trunk (HR)

7th A-IF trunk (HR)

Reserved for CCS7 / X.25

1 2 3 4 5 6 7 80001 01 02 03 04 05 0602 07 08 09 10 11 12 13 1403 15 17 18 19 20 21 22 2304 24 25 26 27 28 29 30 3105 01 02 03 04 05 0606 07 08 09 10 11 12 13 1407 15 17 18 19 20 21 22 2308 24 25 26 27 28 29 30 3109 01 02 03 04 05 0610 07 08 09 10 11 12 13 1411 15 17 18 19 20 21 22 2312 24 25 26 27 28 29 30 3113 01 02 03 04 05 0614 07 08 09 10 11 12 13 1415 15 17 18 19 20 21 22 2316 24 25 26 27 28 29 30 3117 01 02 03 04 05 0618 07 08 09 10 11 12 13 1419 15 17 18 19 20 21 22 2320 24 25 26 27 28 29 30 3121 01 02 03 04 05 0622 07 08 09 10 11 12 13 1423 15 17 18 19 20 21 22 2324 24 25 26 27 28 29 30 3125 01 02 03 04 05 0626 07 08 09 10 11 12 13 1427 15 17 18 19 20 21 22 2328 24 25 26 27 28 29 30 3129 --- --- --- --- --- --- --- ---30 --- --- --- --- --- --- --- ---31 --- --- --- --- --- --- --- ---

LAPD



65890 v5 /01.08.2005/AlEc12

Channel allocation for circuit types D and EChannel allocation for circuit types D and E

1st A-IF trunk (HS2&EFR&FR&HR&D144)

2nd A-IF trunk (HS2&EFR&FR&HR&D144)

1st A-IF trunk (HS4&EFR&FR&HR&D144)

1 2 3 4 5 6 7 80001 0102 02 0303 04 0504 06 0705 08 0906 10 1107 12 1308 14 1509 16 1710 18 1911 20 2112 22 2313 24 2514 26 2715 28 2916 30 3117 0118 02 0319 04 0520 06 0721 08 0922 10 1123 12 1324 14 1525 16 1726 18 1927 20 2128 22 2329 24 2530 26 2731 28 29

LAPD

1 2 3 4 5 6 7 8000102 0203 0304 0405 0506 0607 0708 0809 0910 1011 1112 1213 1314 1415 1516 1617 1718 1819 1920 2021 2122 2223 2324 2425 2526 2627 2728 2829 2930 3031 31

LAPD



65890 v5 /01.08.2005/AlEc13

Mixed allocationsMixed allocations

1st A-IF trunk

2nd A-IF trunk

3rd A-IF trunk (HR)

4th A-IF trunk (HR)

5th A-IF trunk (HR)

6th A-IF trunk (HR)

1st A-IF trunk

2nd A-IF trunk (HS2&EFR&FR&HR&D144)

3rd A-IF trunk (HS4&EFR&FR&HR&D144)

1 2 3 4 5 6 7 80001 01 02 0302 04 05 06 0703 08 09 10 1104 12 13 14 1505 16 17 18 1906 20 21 22 2307 24 25 26 2708 28 29 30 3109 01 02 0310 04 05 06 0711 08 09 10 1112 12 13 14 1513 16 17 18 1914 20 21 22 2315 24 25 26 2716 28 29 30 3117 01 02 03 04 05 0618 07 08 09 10 11 12 13 1419 15 17 18 19 20 21 22 2320 24 25 26 27 28 29 30 3121 01 02 03 04 05 0622 07 08 09 10 11 12 13 1423 15 17 18 19 20 21 22 2324 24 25 26 27 28 29 30 3125 01 02 03 04 05 0626 07 08 09 10 11 12 13 1427 15 17 18 19 20 21 22 2328 24 25 26 27 28 29 30 3129 01 02 03 04 05 0630 07 08 09 10 11 12 13 1431 15 17 18 19 20 21 22 23

LAPD

1 2 3 4 5 6 7 80001 01 02 0302 04 05 06 0703 08 09 10 1104 12 13 14 1505 16 17 18 1906 20 21 22 2307 24 25 26 2708 28 29 30 3109 0110 02 0311 04 0512 06 0713 08 0914 10 1115 12 1316 14 1517 16 1718 18 1919 20 2120 22 2321 24 2522 26 2723 28 2924 30 3125 0126 0227 0328 0429 0530 0631 07

LAPD



65890 v5 /01.08.2005/AlEc14

Channel allocation in Channel allocation in AterAter interface:interface:mixed configurationmixed configuration

Plug-in unit

*)2...62...8

TR16-S

ET2E

TCH

Capacity unit onAter: 16 kbit/s

(Circuit types A,C,F)

*)1...21...3*)29...90or 29...120

*) if BSC-side submultiplexing is carried out by the SMUX unit and three PCMs aremultiplexed onto Ater.

Capacity unit onAter: 8 kbit/s

(Circuit type B)

Capacity unit onAter: 2 x 16 kbit/s

(Circuit type D)

Capacity unit onAter: 4 x 16 kbit/s

(Circuit type E)

2...14

1...4

29...210

2...4

1...2

29...60

2

1

30



65890 v5 /01.08.2005/AlEc15

TCSM2E InternalTCSM2E Internal--block diagramblock diagram

CPU186

ESO

ESI

V.24

TRUNKTIMINGBLOCK

LI

TRCI SUBA TRI CLOCKS

UB

+ 5V

VDU

ESO

ESI

Ater (BSC)

A(MSC)

TCSM2E

LIET2EET2EET2EET2E

TRCO

TR16-S

01

TR16-S

25

10

TR16-S

13

RAM

PROM

FLASH

LAPD

PSC1

1234567

O


• Descriptions\ Product descriptions\ Product description of TCSM2A and TCSM2E\Architecture of TCSM2A and TCSM2E

65890 v5 /01.08.2005/AlEc16

TranscoderTranscoder hardwarehardware


• Descriptions\ Product descriptions\ Product description of TCSM2A and TCSM2E\Configurations, capacity, and performance of TCSM2A and TCSM2E\ Rack capacityof TCSM2E

65890 v5 /01.08.2005/AlEc17

Front panel of TRCO Front panel of ET2E

Local user interface

ESI: ext. synchr. input ESO: ext. synchr. outputOn: If sychron. input with highest priority is used.Off: Opposite/ Plesiochrone

Clock alarm

Alarm TRCO

Alarm TR16

Reset flash

PCM interface

0

1

On: Basic time error (sychronisation)

Incoming direction alarm: -2Mb signal. missing -Loss of frame alignment-AIS alarm -BER > 10-3

B3 alarm: remote end alarm

Outgoing direction alarm: -ET sends AIS -Internal loop is created.

Both

PCM

0

PCM

1

B3

B3


• Descriptions\ Hardware descriptions\ Plug-in unit descriptions\ TRCO\ TRCOOverview

• Descriptions\ Hardware descriptions\ Plug-in unit descriptions\ ET2E, ET2E-C, ET2E-S, ET2E-SC\ ET2E, ET2E-C, ET2E-S, ET2E-SC overview

65890 v5 /01.08.2005/AlEc18

Exercise: Exercise: TranscoderTranscoder operationoperation

BSC MSCTCSM2

Complete the picture according to the TCSM2 in your classroom!

ET... ET...ET...

ET...

ET...

Refer to S11.5 Documentation:•Integrate\ Q1 Interface\ BSS transmission management\ Configuring a new transcoder\ Configuring a TCSM unit (TCSM2)• Optimise and Expand\ Transmission\ Modifying an existing transcoder configuration•Commission\ Commissioning TCSM2\ Commissioning TCSM2

Exercise: Transcoder operation. Duration: 25 min.

You are working with TCSM No…….

Give the location (coordinate) of the TC1C cartridge:

_____________________________________________________________________

Give the location of the ET1TC cartridge:

_____________________________________________________________________

How many ET plug-in units are used?

_____________________________________________________________________How many TR16 cards are used?

_____________________________________________________________________Are there through-connected timeslots?

_____________________________________________________________________

How are the TC PCMs configured (FR/HR/data…)?

_____________________________________________________________________

Add a (fictive) TC-PCM to your TCSM2, configured as EFR. If you cannot provide the additional HW to the TCSM do not make a unit restart!

_____________________________________________________________________

Make a through-connection from TS16 to TS… on the highway PCM (only possible if you can provide the additional HW to the TCSM!).

_____________________________________________________________________

What plug-in units had to be added to implement the new configuration?

_____________________________________________________________________

Delete the just created TC-PCM and the through-connection.

_____________________________________________________________________

Documents

03a_tcsm2 Basic Operation